Living gymnosperms comprise four major groups:cycads,Ginkgo,conifers,and gnetophytes.Relationships among/within these lineages have not been fully resolved.Next generation sequencing has made available a large number ...Living gymnosperms comprise four major groups:cycads,Ginkgo,conifers,and gnetophytes.Relationships among/within these lineages have not been fully resolved.Next generation sequencing has made available a large number of sequences,including both plastomes and single-copy nuclear genes,for reconstruction of solid phylogenetic trees.Recent advances in gymnosperm phylogenomic studies have updated our knowledge of gymnosperm systematics.Here,we review major advances of gymnosperm phylogeny over the past 10 years and propose an updated classification of extant gymnosperms.This new classification includes three classes(Cycadopsida,Ginkgoopsida,and Pinopsida),five subclasses(Cycadidae,Ginkgoidae,Cupressidae,Pinidae,and Gnetidae),eight orders(Cycadales,Ginkgoales,Araucariales,Cupressales,Pinales,Ephedrales,Gnetales,and Welwitschiales),13 families,and 86 genera.We also described six new tribes including Acmopyleae Y.Yang,Austrocedreae Y.Yang,Chamaecyparideae Y.Yang,Microcachrydeae Y.Yang,Papuacedreae Y.Yang,and Prumnopityeae Y.Yang,and made 27 new combinations in the genus Sabina.展开更多
The rapid expansion of next-generation sequencing （NGS） has generated a powerful array of approaches to address fundamental questions in biology. Several genome-partitioning strategies to sequence selected subsets o...The rapid expansion of next-generation sequencing （NGS） has generated a powerful array of approaches to address fundamental questions in biology. Several genome-partitioning strategies to sequence selected subsets of the genome have emerged in the fields of phylogenomics and evolutionary genomics. In this review, we summarize the applications, advantages and limitations of four NGS-based genome- partitioning approaches in plant phylogenomics： genome skimming, transcriptome sequencing （RNA- seq）, restriction site associated DNA sequencing （RAD-Seq）, and targeted capture （Hyb-seq）. Of these four genome-partitioning approaches, targeted capture （especially Hyb-seq） shows the greatest promise for plant phy^ogenetics over the next fex~ years. This reviex~ wi~ aid ~esea^chers in their selection of appropriate genome-partitioning approaches to address questions of evolutionary scale, where we anticipate continued development and expansion ofwhole-genome sequencing strategies in the fields of plant phylogenomics and evolutionary biology research.展开更多
The cosmopolitan family Solanaceae,which originated and first diversified in South America,is economically important.The tribe Hyoscyameae is one of the three clades in Solanaceae that occurs outside of the New World;...The cosmopolitan family Solanaceae,which originated and first diversified in South America,is economically important.The tribe Hyoscyameae is one of the three clades in Solanaceae that occurs outside of the New World;Hyoscyameae genera are distributed mainly in Europe and Asia,and have centers of species diversity in the Qinghai-Tibet Plateau and adjacent regions.Although many phylogenetic studies have focused on Solanaceae,the phylogenetic relationships within the tribe Hyoscyameae and its biogeographic history remain obscure.In this study,we reconstructed the phylogeny of Hyoscyameae based on whole chloroplast genome data,and estimated lineage divergence times according to the newly reported fruit fossil from the Eocene Patagonia,Physalis infinemundi,the earliest known fossil of Solanaceae.We reconstructed a robust phylogeny of Hyoscyameae that reveals the berry fruit-type Atropa is sister to the six capsule-bearing genera(Hyoscyameae sensu stricto),Atropanthe is sister to the clade(Scopolia,Physochlaina,Przewalskia),and together they are sister to the robustly supported AnisoduseHyoscyamus clade.The stem age of Hyoscyameae was inferred to be in the Eocene(47.11 Ma,95%HPD:36.75e57.86 Ma),and the crown ages of Hyoscyameae sensu stricto were estimated as the early Miocene(22.52 Ma,95%HPD:15.19e30.53 Ma),which shows a close correlation with the rapid uplift of the Qinghai-Tibet Plateau at the Paleogene/Neogene boundary.Our results provide insights into the phylogenetic relationships and the history of the biogeographic diversification of the tribe Hyoscyameae,as well as plant diversification on the Qinghai-Tibet Plateau.展开更多
Spiders are among the most varied terrestrial predators,with highly diverse morphology,ecology,and behavior.Morphological and molecular data have greatly contributed to advances in the phylogeny and evolutionary dynam...Spiders are among the most varied terrestrial predators,with highly diverse morphology,ecology,and behavior.Morphological and molecular data have greatly contributed to advances in the phylogeny and evolutionary dynamics of spiders.Here,we performed comprehensive mitochondrial phylogenomics analysis on 78 mitochondrial genomes(mitogenomes)representing 29 families;of these,23 species from eight families were newly generated.Mesothelae retained the same gene arrangement as the arthropod ancestor(Limulus polyphemus),while Opisthothelae showed extensive rearrangement,with 12 rearrangement types in transfer RNAs(tRNAs)and control region.Most spider tRNAs were extremely truncated and lacked typical dihydrouridine or TΨC arms,showing high tRNA structural diversity;in particular,trnS1 exhibited anticodon diversity across the phylogeny.The evolutionary rates of mitochondrial genes were potentially associated with gene rearrangement or truncated tRNAs.Both mitogenomic sequences and rearrangements possessed phylogenetic characteristics,providing a robust backbone for spider phylogeny,as previously reported.The monophyly of suborder,infraorder,retrolateral tibial apophysis clade,and families(except for Pisauridae)was separately supported,and high-level relationships were resolved as(Mesothelae,(Mygalomorphae,(Entelegynae,(Synspermiata,Hypochilidae)))).The phylogenetic positions of several families were also resolved(e.g.,Eresidae,Oecobiidae and Titanoecidae).Two reconstructions of ancestral web type obtained almost identical results,indicating that the common ancestor of spiders likely foraged using a silk-lined burrow.This study,the largest mitochondrial phylogenomics analysis of spiders to date,highlights the usefulness of mitogenomic data not only for providing efficient phylogenetic signals for spider phylogeny,but also for characterizing trait diversification in spider evolution.展开更多
Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae,comprising approximately 520 species from the Northern Hemisphere.A comprehensive infrageneric classification,supported by robust ...Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae,comprising approximately 520 species from the Northern Hemisphere.A comprehensive infrageneric classification,supported by robust phylogenetic trees and corroborated by morphological and other data,has not yet been published.For the first time,we recovered a well-resolved nuclear phylogeny of Saussurea consisting of four main clades,which was also supported by morphological data.Our analyses show that ancient hybridization is the most likely source of deep cytoplasmic-nuclear conflict in Saussurea,and a phylogeny based on nuclear data is more suitable than one based on chloroplast data for exploring the infrageneric classification of Saussurea.Based on the nuclear phylogeny obtained and morphological characters,we proposed a revised infrageneric taxonomy of Saussurea,which includes four subgenera and 13 sections.Specifically,1)S.sect.Cincta,S.sect.Gymnocline,S.sect.Lagurostemon,and S.sect.Strictae were moved from S.subg.Saussurea to S.subg.Amphilaena,2)S.sect.Pseudoeriocoryne was moved from S.subg.Eriocoryne to S.subg.Amphilaena,and 3)S.sect.Laguranthera was moved from S.subg.Saussurea to S.subg.Theodorea.展开更多
Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized genera.Recognition and delineation of genera within this family have varied greatly.The three-sub...Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized genera.Recognition and delineation of genera within this family have varied greatly.The three-subfamily classification of Dryopteridaceae was based primarily on molecular phylogenetic relationships but lacked morphological evidence,and the phylogenetic relationships of the subfamilies and genera of Dryopteridaceae are only partially resolved.A comprehensive and robust phylogeny is urgently needed.The heterogeneous morphology of the current members of Dryopteridaceae makes the family and its subfamilies difficult to define by single morphological characteristics or even character combinations.We carried out phylogenetic analyses to reconstruct a highly supported phylogeny of Dryopteridaceae.Our analyses recovered 24 strongly supported clades grouped into seven major clades of Dryopteridaceae.Seven morphological characters including habit,rhizome shape,frond morphology,rachis-costae architecture,appendages on stipe base and lamina,and soral arrangement were found to be informative for identifying different major clades and clades in Dryopteridaceae.Based on phylogenetic reconstruction and morphological analysis,we presented an updated infra-familial classification of Dryopteridaceae with seven subfamilies and 24 genera including four newly proposed subfamilies(Ctenitidoideae,Lastreopsidoideae,Pleocnemioideae,and Polystichopsidoideae).Morphological character combinations of each subfamily are summarized,and a key is provided.Most genera sensu PPG I are recognized,with Stigmatopetris reclassified into Dryopteridoideae and Arthrobotrya considered a synonym of Teratophyllum.A new genus Pseudarachniodes is introduced.This revised classification will serve as a foundational framework for future investigations on taxonomy,biogeography,and diversification of the most species-rich Dryopteridaceae in ferns.展开更多
Angiosperms(flowering plants) are by far the most diverse land plant group with over 300,000 species. The sudden appearance of diverse angiosperms in the fossil record was referred to by Darwin as the “abominable mys...Angiosperms(flowering plants) are by far the most diverse land plant group with over 300,000 species. The sudden appearance of diverse angiosperms in the fossil record was referred to by Darwin as the “abominable mystery,”hence contributing to the heightened interest in angiosperm evolution. Angiosperms display wide ranges of morphological, physiological,and ecological characters, some of which have probably influenced their species richness. The evolutionary analyses of these characteristics help to address questions of angiosperm diversification and require well resolved phylogeny. Following the great successes of phylogenetic analyses using plastid sequences,dozens to thousands of nuclear genes from next-generation sequencing have been used in angiosperm phylogenomic analyses, providing well resolved phylogenies and new insights into the evolution of angiosperms. In this review we focus on recent nuclear phylogenomic analyses of large angiosperm clades, orders, families,and subdivisions of some families and provide a summarized Nuclear Phylogenetic Tree of Angiosperm Families. The newly established nuclear phylogenetic relationships are highlighted and compared with previous phylogenetic results. The sequenced genomes of Amborella,Nymphaea, Chloranthus, Ceratophyllum, and species of monocots, Magnoliids, and basal eudicots, have facilitated the phylogenomics of relationships among five major angiosperms clades. All but one of the 64 angiosperm orders were included in nuclear phylogenomics with well resolved relationships except the placements of several orders. Most families have been included with robust and highly supported placements, especially for relationships within several large and important orders and families.Additionally, we examine the divergence time estimation and biogeographic analyses of angiosperm on the basis of the nuclear phylogenomic frameworks and discuss the differences compared with previous analyses. Furthermore,we discuss the implications of nuclear phylogenomic analyses on ancestral reconstruction of morphological, physiological, and ecological characters of angiosperm groups, limitations of current nuclear phylogenomic studies, and the taxa that require future attention.展开更多
Plant root-nodule symbiosis(RNS)with mutualistic nitrogen-fixing bacteria is restricted to a single clade of angiosperms,the Nitrogen-Fixing Nodulation Clade(NFNC),and is best understood in the legume family.Nodulatin...Plant root-nodule symbiosis(RNS)with mutualistic nitrogen-fixing bacteria is restricted to a single clade of angiosperms,the Nitrogen-Fixing Nodulation Clade(NFNC),and is best understood in the legume family.Nodulating species share many commonalities,explained either by divergence from a common ancestor over 100 million years ago or by convergence following independent origins over that same time period.Regardless,comparative analyses of diverse nodulation syndromes can provide insights into constraints on nodulation—what must be acquired or cannot be lost for a functional symbiosis—and the latitude for Plant Communications Genomic landscape of nodulation variation in the symbiosis.However,much remains to be learned about nodulation,especially outside of legumes.Here,we employed a large-scale phylogenomic analysis across 88 species,complemented by 151 RNA-seq libraries,to elucidate the evolution of RNS.Our phylogenomic analyses further emphasize the uniqueness of the transcription factor NIN as a master regulator of nodulation and identify key muta-tions that affect its function across the NFNC.Comparative transcriptomic assessment revealed nodule-specific upregulated genes across diverse nodulating plants,while also identifying nodule-specific and nitrogen-response genes.Approximately 70%of symbiosis-related genes are highly conserved in the four representative species,whereas defense-related and host-range restriction genes tend to be lineage specific.Our study also identified over 900000 conserved non-coding elements(CNEs),over 300000 of which are unique to sampled NFNC species.NFNC-specific CNEs are enriched with the active H3K9ac mark and are correlated with accessible chromatin regions,thus representing a pool of candidate regula-tory elements for genes involved in RNS.Collectively,our results provide novel insights into the evolution of nodulation and lay a foundation for engineering of RNS traits in agriculturally important crops.展开更多
Early efforts to classify Mortierellaceae were based on macro-and micromorphology,but sequencing and phylogenetic studies with ribosomal DNA(rDNA)markers have demonstrated conflicting taxonomic groupings and polyphyle...Early efforts to classify Mortierellaceae were based on macro-and micromorphology,but sequencing and phylogenetic studies with ribosomal DNA(rDNA)markers have demonstrated conflicting taxonomic groupings and polyphyletic genera.Although some taxonomic confusion in the family has been clarified,rDNA data alone is unable to resolve higher level phylogenetic relationships within Mortierellaceae.In this study,we applied two parallel approaches to resolve the Mortierel-laceae phylogeny:low coverage genome(LCG)sequencing and high-throughput,multiplexed targeted amplicon sequenc-ing to generate sequence data for multi-gene phylogenetics.We then combined our datasets to provide a well-supported genome-based phylogeny having broad sampling depth from the amplicon dataset.Resolving the Mortierellaceae phylogeny into monophyletic genera resulted in 13 genera,7 of which are newly proposed.Low-coverage genome sequencing proved to be a relatively cost-effective means of generating a high-confidence phylogeny.The multi-gene phylogenetics approach enabled much greater sampling depth and breadth than the LCG approach,but has limitations too.We present this work to resolve some of the taxonomic confusion and provide a genus-level framework to empower future studies on Mortierellaceae diversity and evolution.展开更多
Ciliates are one of the oldest living eukaryotic unicellular organisms, widely distributed in the waters around the world. As a typical marine oligotrich ciliate, Strombidium sulcatum plays an important role in marine...Ciliates are one of the oldest living eukaryotic unicellular organisms, widely distributed in the waters around the world. As a typical marine oligotrich ciliate, Strombidium sulcatum plays an important role in marine food webs and energy flow. Here we report the first deep se- quencing and analyses of RNA-Seq data from Strombidium sulcatum. We generated 42,640 unigenes with an N50 of 1,451 bp after de novo assembly and removing rRNA, mitochondrial and bacteria contaminants. We employed SPOCS to detect orthologs from S. sulcatum and 17 other ciliates, and then carried out the phyloge- nomic reconstruction using 127 single copy orthologs. In phylogenomic analyses, concatenated trees have similar topological structures with concordance tree on the class level. Together with phylogenetic networks analysis, it aroused more doubts about the placement of Protocruzia, Mesodinium and Myrionecta. While epi- plasmic proteins are known to be related to morphological characteristics, we found the potential relationship between gene expression of epiplasmic proteins and morphological characteristics. This work supports the use of high throughput approaches for phylogenomic analysis as well as correlation analysis between expression level of target genes and morphological characteristics.展开更多
Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow distribution.Previous phylogenetic studies revealed an unexpected,isolated phylogenetic position...Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow distribution.Previous phylogenetic studies revealed an unexpected,isolated phylogenetic position of Ps.gracilis.Here we conducted phylogenomic analysis by sampling populations of Ps.gracilis and its sympatric species Ps.nanunica and Sinosasa polytricha reflecting different genomic signals,by deep genome skimming.Integrating molecular evidence from chloroplast genes and genome-wide SNPs,we deciphered the phylogenetic relationships of Ps.gracilis.Both plastid and nuclear data indicate that Ps.gracilis is more closely related to Sinosasa,which is discordant with the taxonomic treatment.To further explore this molecular-morphological conflict,we screened 411“perfect-copy”syntenic genes to reconstruct phylogenies using both the concatenation and coalescent methods.We observed extensive discordance between gene trees and the putative species tree.A significant hybridization event was detected based on 411 genes from the D subgenome,showing Ps.gracilis was a hybrid descendant between Sinosasa longiligulata and Ps.nanunica,with 63.56%and 36.44%inheritance probabilities of each parent.Moreover,introgression events were detected in the C subgenome between Ps.gracilis and S.polytricha in the same distribution region.Our findings suggest that sympatric hybridization and introgression play a crucial role in the origin of Ps.gracilis.By providing an empirical example of bamboo of hybrid origin using comprehensive analyses based on genomic data from different inheritance systems and morphological characters,our study represents a step forward in understanding of reticulate evolution of bamboos.展开更多
Laurasiatheria is one of the richest and most diverse superorders of placental mammals. Because this group had a rapid evolutionary radiation, the phylogenetic relationships among the six orders of Laurasiatheria rema...Laurasiatheria is one of the richest and most diverse superorders of placental mammals. Because this group had a rapid evolutionary radiation, the phylogenetic relationships among the six orders of Laurasiatheria remain a subject of heated debate and several issues related to its phylogeny remain open. Reconstructing the true phylogenetic relationships of Laurasiatheria is a significant case study in evolutionary biology due to the diversity of this suborder and such research will have significant implications for biodiversity conservation. We review the higher-level （inter-ordinal） phylogenies of Laurasiatheria based on previous cytogenetic, morphological and molecular data, and discuss the controversies of its phylogenetic relationship. This review aims to outline future researches on Laurasiatheria phylogeny and adaptive evolution.展开更多
Ruminants(Ruminantia) are among the most successful herbivorous mammals, exhibiting wideranging morphological and ecological characteristics(such as headgear and multichambered stomach)and including various key livest...Ruminants(Ruminantia) are among the most successful herbivorous mammals, exhibiting wideranging morphological and ecological characteristics(such as headgear and multichambered stomach)and including various key livestock species(e. g.,cattle, buffalo, yak, sheep, and goat). Understanding their evolution is of great significance not only in scientific research but also in applications potential for human society. The rapid growth of genomic resources provides unprecedented opportunities to dissect the evolutionary histories and molecular mechanisms underlying the distinct characteristics of ruminants. Here we summarize our current understanding of the genetic, morphological, and ecological diversity of ruminants and provide prospects for future studies.展开更多
Panax stipuleanatus(Araliaceae) is an endangered and medicinally important plant endemic to China.However, phylogenetic relationships within the genus Panax have remained unclear. In this study, we sequenced the compl...Panax stipuleanatus(Araliaceae) is an endangered and medicinally important plant endemic to China.However, phylogenetic relationships within the genus Panax have remained unclear. In this study, we sequenced the complete plastome of P. stipuleanatus and included previously reported Panax plastomes to better understand the relationships between species and plastome evolution within the genus Panax.The plastome of P. stipuleanatus is 156,069 base pairs(bp) in length, consisting of a pair of inverted repeats(IRs, each 25,887 bp) that divide the plastome into a large single copy region(LSC, 86,126 bp) and a small single copy region(SSC, 8169 bp). The plastome contains 114 unigenes(80 protein-coding genes,30 tRNA genes, and 4 r RNA genes). Comparative analyses indicated that the plastome gene content and order, as well as the expansion/contraction of the IR regions, are all highly conserved within Panax. No significant positive selection in the plastid protein-coding genes was observed across the eight Panax species, suggesting the Panax plastomes may have undergone a strong purifying selection. Our phylogenomic analyses resulted in a phylogeny with high resolution and supports for Panax. Nine proteincoding genes and 10 non-coding regions presented high sequence divergence, which could be useful for identifying different Panax species.展开更多
Cannabaceae is an economically important family that includes ten genera and ca. 117 accepted species.To explore the structure and size variation of their plastomes, we sequenced ten plastomes representing all ten gen...Cannabaceae is an economically important family that includes ten genera and ca. 117 accepted species.To explore the structure and size variation of their plastomes, we sequenced ten plastomes representing all ten genera of Cannabaceae. Each plastome possessed the typical angiosperm quadripartite structure and contained a total of 128 genes. The Inverted Repeat(IR) regions in five plastomes had experienced small expansions(330 e983 bp) into the Large Single-Copy(LSC) region. The plastome of Chaetachme aristata has experienced a 942-bp IR contraction and lost rpl22 and rps19 in its IRs. The substitution rates of rps19 and rpl22 decreased after they shifted from the LSC to IR. A 270-bp inversion was detected in the Parasponia rugosa plastome, which might have been mediated by 18-bp inverted repeats. Repeat sequences, simple sequence repeats, and nucleotide substitution rates varied among these plastomes.Molecular markers with more than 13% variable sites and 5% parsimony-informative sites were identified, which may be useful for further phylogenetic analysis and species identification. Our results show strong support for a sister relationship between Gironniera and Lozanell(BS ? 100). Celtis, CannabisHumulus, Chaetachme-Pteroceltis, and Trema-Parasponia formed a strongly supported clade, and their relationships were well resolved with strong support(BS ? 100). The availability of these ten plastomes provides valuable genetic information for accurately identifying species, clarifying taxonomy and reconstructing the intergeneric phylogeny of Cannabaceae.展开更多
Cobetia marina is a model proteobacteria in researches on marine biofouling. Its taxonomic nomenclature has been revised many times over the past few decades. To better understand the role of the surface-associated li...Cobetia marina is a model proteobacteria in researches on marine biofouling. Its taxonomic nomenclature has been revised many times over the past few decades. To better understand the role of the surface-associated lifestyle of C. marina and the phylogeny of the family Halomonadaceae, we sequenced the entire genome of C. marina JCM 21022T using single molecule real-time sequencing technology （SMRT） and performed comparative genomics and phylogenomics analyses. The circular chromosome was 4 176 300 bp with an average GC content of 62.44% and contained 3 611 predicted coding sequences, 72 tRNA genes, and 21 rRNA genes. The C. marina JCM 2102U genome contained a set of crucial genes involved in surface colonization processes. The comparative genome analysis indicated the significant differences between C. marina JCM 21022T and Cobetia amphilecti KMM 296 （formerly named C. marina KMM 296） resulted from sequence insertions or deletions and chromosomal recombination. Despite these differences, pan and core genome analysis showed similar gene functions between the two strains. The phylogenomic study of the family Halomonadaceae is relationships were well resolved among every genera Cobetia, Kushneria, Zymobacter, and Halotalea. reported here for the first time. We found that the tested, including Chromohalobacter, Halomonas,展开更多
Previous studies recognized three major lineages of the family Costaceae:a South American clade,an Asian clade and a Costus clade.However,the genus Hellenia within the Asian clade has been shown to be non-monophyletic...Previous studies recognized three major lineages of the family Costaceae:a South American clade,an Asian clade and a Costus clade.However,the genus Hellenia within the Asian clade has been shown to be non-monophyletic and its morphology has not been studied carefully.Therefore,the complete plastid genomes of Hellenia species were obtained and the monophyly of Hellenia was tested through four different datasets in this study.Plastid phylogenomic analyses of Costaceae revealed that Hellenia is strongly supported as paraphyletic.Two major clades are recovered,namely the Hellenia s.s.subclade and the Parahellenia subclade.Phylogenetic analyses based on an enlarged taxon sampling of the Asian clade using a two chloroplast markers dataset(trnK intron and trnL-F spacer)confirmed the paraphyly of Hellenia.Meanwhile,morphological analyses suggested that members of the Parahellenia subclade differ from the remaining Hellenia species in many characters including inflorescences,bracts,stigma,axillary buds,floral tubes and labellum.According to the present molecular and morphological evidence,the latter subclade is recognized as a new genus,Parahellenia.Two new species are described,four new combinations are made,and identification keys are also provided.展开更多
Laurasiatheria is one of the richest and most diverse superorders of placental mammals.Because this group had a rapid evolutionary radiation,the phylogenetic relationships among the six orders of Laurasiatheria remain...Laurasiatheria is one of the richest and most diverse superorders of placental mammals.Because this group had a rapid evolutionary radiation,the phylogenetic relationships among the six orders of Laurasiatheria remain a subject of heated debate and several issues related to its phylogeny remain open.Reconstructing the true phylogenetic relationships of Laurasiatheria is a significant case study in evolutionary biology due to the diversity of this suborder and such research will have significant implications for biodiversity conservation.We review the higher-level(inter-ordinal)phylogenies of Laurasiatheria based on previous cytogenetic,morphological and molecular data,and discuss the controversies of its phylogenetic relationship.This review aims to outline future researches on Laurasiatheria phylogeny and adaptive evolution.展开更多
Lycophytes are an ancient clade of the non-flowering vascular plants with chromosome numbers that vary from tens to hundreds.They are an excellent study system for examining whole-genome duplications(WGDs),or polyploi...Lycophytes are an ancient clade of the non-flowering vascular plants with chromosome numbers that vary from tens to hundreds.They are an excellent study system for examining whole-genome duplications(WGDs),or polyploidization,in spore-dispersed vascular plants.However,a lack of genome sequence data limits the reliable detection of very ancient WGDs,small-scale duplications(SSDs),and recent WGDs.Here,we integrated phylogenomic analysis and the distribution of synonymous substitutions per synonymous sites(Ks)of the transcriptomes of 13 species of lycophytes to identify,locate,and date multiple WGDs in the lycophyte family Lycopodiaceae.Additionally,we examined the genus Phlegmariurus for signs of genetic discordance,which can provide valuable insight into the underlying causes of such conflict(e.g.,hybridization,incomplete lineage sorting,or horizontal gene transfer).We found strong evidence that two WGD events occurred along the phylogenetic backbone of Lycopodiaceae,with one occurring in the common ancestor of extant Phlegmariurus(Lycopodiaceae)approximately 22-23 million years ago(Mya)and the other occurring in the common ancestor of Lycopodiaceae around 206-214 Mya.Interestingly,we found significant genetic discordance in the genus Phlegmariurus,indicating that the genus has a complex evolutionary history.This study provides molecular evidence for multiple WGDs in Lycopodiaceae and offers phylogenetic clues to the evolutionary history of Lycopodiaceae.展开更多
Cytidine-to-uridine(C-to-U)RNA editing is common in coding regions of organellar genomes throughout land plants.In most cases RNA editing alters translated amino acids or creates new start codons,potentially confounds...Cytidine-to-uridine(C-to-U)RNA editing is common in coding regions of organellar genomes throughout land plants.In most cases RNA editing alters translated amino acids or creates new start codons,potentially confounds phylogenetic reconstructions.In this study,we used the spike moss genus Selaginella(lycophytes),which has the highest frequency of RNA editing,as a model to test the effects of extreme RNA editing on phylogenetic reconstruction.We predicted the C-to-U RNA editing sites in coding regions of 18 Selaginella plastomes,and reconstructed the phylogenetic relationships within Selaginella based on three data set pairs consisted of plastome or RNA-edited coding sequences,first and second codon positions,and translated amino acid sequences,respectively.We predicted between 400 and 3100 RNA editing sites of 18 Selaginella plastomes.The numbers of RNA editing sites in plastomes were highly correlated with the GC content of first and second codon positions,but not correlated with the GC content of plastomes as a whole.Contrast phylogenetic analyses showed that there were substantial differences(e.g.,the placement of clade B in Selaginella)between the phylogenies generated by the plastome and RNA-edited data sets.This empirical study provides evidence that extreme C-to-U RNA editing in the coding regions of organellar genomes alters the sequences used for phylogenetic reconstruction,and might even confound phylogenetic reconstruction.Therefore,RNA editing sites should be corrected when plastid or mitochondrial genes are used for phylogenetic studies,particularly in those lineages with abundant organellar RNA editing sites,such as hornworts,quillworts,spike mosses,and some seed plants.展开更多
基金supported by the National Natural Science Foundation of China(31970205,31870206)the Metasequoia funding of the Nanjing Forestry University,China。
文摘Living gymnosperms comprise four major groups:cycads,Ginkgo,conifers,and gnetophytes.Relationships among/within these lineages have not been fully resolved.Next generation sequencing has made available a large number of sequences,including both plastomes and single-copy nuclear genes,for reconstruction of solid phylogenetic trees.Recent advances in gymnosperm phylogenomic studies have updated our knowledge of gymnosperm systematics.Here,we review major advances of gymnosperm phylogeny over the past 10 years and propose an updated classification of extant gymnosperms.This new classification includes three classes(Cycadopsida,Ginkgoopsida,and Pinopsida),five subclasses(Cycadidae,Ginkgoidae,Cupressidae,Pinidae,and Gnetidae),eight orders(Cycadales,Ginkgoales,Araucariales,Cupressales,Pinales,Ephedrales,Gnetales,and Welwitschiales),13 families,and 86 genera.We also described six new tribes including Acmopyleae Y.Yang,Austrocedreae Y.Yang,Chamaecyparideae Y.Yang,Microcachrydeae Y.Yang,Papuacedreae Y.Yang,and Prumnopityeae Y.Yang,and made 27 new combinations in the genus Sabina.
基金supported by the Large-scale Scientific Facilities of the Chinese Academy of Sciences (Grant No: 2017-LSFGBOWS-01)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000)the Program of Science and Technology Talents Training of Yunnan Province (2017HA014)
文摘The rapid expansion of next-generation sequencing （NGS） has generated a powerful array of approaches to address fundamental questions in biology. Several genome-partitioning strategies to sequence selected subsets of the genome have emerged in the fields of phylogenomics and evolutionary genomics. In this review, we summarize the applications, advantages and limitations of four NGS-based genome- partitioning approaches in plant phylogenomics： genome skimming, transcriptome sequencing （RNA- seq）, restriction site associated DNA sequencing （RAD-Seq）, and targeted capture （Hyb-seq）. Of these four genome-partitioning approaches, targeted capture （especially Hyb-seq） shows the greatest promise for plant phy^ogenetics over the next fex~ years. This reviex~ wi~ aid ~esea^chers in their selection of appropriate genome-partitioning approaches to address questions of evolutionary scale, where we anticipate continued development and expansion ofwhole-genome sequencing strategies in the fields of plant phylogenomics and evolutionary biology research.
基金We thank Dr.Xiao-Feng Chi and Dr.Ofelia Vargas-Ponce for contributing the whole chloroplast genome sequences of Anisodus tanguticus(Maxim.)Pascher and Physalis philadelphica Lam.before the release in NCBI.This work was supported by the Beijing Natural Science Foundation(Grant No.5192012)National Natural Science Foundation of China(grant number 32070235)the China Scholarship Council(Grant No.201906515009)。
文摘The cosmopolitan family Solanaceae,which originated and first diversified in South America,is economically important.The tribe Hyoscyameae is one of the three clades in Solanaceae that occurs outside of the New World;Hyoscyameae genera are distributed mainly in Europe and Asia,and have centers of species diversity in the Qinghai-Tibet Plateau and adjacent regions.Although many phylogenetic studies have focused on Solanaceae,the phylogenetic relationships within the tribe Hyoscyameae and its biogeographic history remain obscure.In this study,we reconstructed the phylogeny of Hyoscyameae based on whole chloroplast genome data,and estimated lineage divergence times according to the newly reported fruit fossil from the Eocene Patagonia,Physalis infinemundi,the earliest known fossil of Solanaceae.We reconstructed a robust phylogeny of Hyoscyameae that reveals the berry fruit-type Atropa is sister to the six capsule-bearing genera(Hyoscyameae sensu stricto),Atropanthe is sister to the clade(Scopolia,Physochlaina,Przewalskia),and together they are sister to the robustly supported AnisoduseHyoscyamus clade.The stem age of Hyoscyameae was inferred to be in the Eocene(47.11 Ma,95%HPD:36.75e57.86 Ma),and the crown ages of Hyoscyameae sensu stricto were estimated as the early Miocene(22.52 Ma,95%HPD:15.19e30.53 Ma),which shows a close correlation with the rapid uplift of the Qinghai-Tibet Plateau at the Paleogene/Neogene boundary.Our results provide insights into the phylogenetic relationships and the history of the biogeographic diversification of the tribe Hyoscyameae,as well as plant diversification on the Qinghai-Tibet Plateau.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK0302)Natural Science Foundation of Gansu Province(20JR5RA252)Innovation and Entrepreneurship Project of Lanzhou University(20210010020,20210010002)。
文摘Spiders are among the most varied terrestrial predators,with highly diverse morphology,ecology,and behavior.Morphological and molecular data have greatly contributed to advances in the phylogeny and evolutionary dynamics of spiders.Here,we performed comprehensive mitochondrial phylogenomics analysis on 78 mitochondrial genomes(mitogenomes)representing 29 families;of these,23 species from eight families were newly generated.Mesothelae retained the same gene arrangement as the arthropod ancestor(Limulus polyphemus),while Opisthothelae showed extensive rearrangement,with 12 rearrangement types in transfer RNAs(tRNAs)and control region.Most spider tRNAs were extremely truncated and lacked typical dihydrouridine or TΨC arms,showing high tRNA structural diversity;in particular,trnS1 exhibited anticodon diversity across the phylogeny.The evolutionary rates of mitochondrial genes were potentially associated with gene rearrangement or truncated tRNAs.Both mitogenomic sequences and rearrangements possessed phylogenetic characteristics,providing a robust backbone for spider phylogeny,as previously reported.The monophyly of suborder,infraorder,retrolateral tibial apophysis clade,and families(except for Pisauridae)was separately supported,and high-level relationships were resolved as(Mesothelae,(Mygalomorphae,(Entelegynae,(Synspermiata,Hypochilidae)))).The phylogenetic positions of several families were also resolved(e.g.,Eresidae,Oecobiidae and Titanoecidae).Two reconstructions of ancestral web type obtained almost identical results,indicating that the common ancestor of spiders likely foraged using a silk-lined burrow.This study,the largest mitochondrial phylogenomics analysis of spiders to date,highlights the usefulness of mitogenomic data not only for providing efficient phylogenetic signals for spider phylogeny,but also for characterizing trait diversification in spider evolution.
基金supported by the National Natural Science Foundation of China(grant no.32200172)Guangzhou Science and technology project(grant no.2023A04J0715).
文摘Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae,comprising approximately 520 species from the Northern Hemisphere.A comprehensive infrageneric classification,supported by robust phylogenetic trees and corroborated by morphological and other data,has not yet been published.For the first time,we recovered a well-resolved nuclear phylogeny of Saussurea consisting of four main clades,which was also supported by morphological data.Our analyses show that ancient hybridization is the most likely source of deep cytoplasmic-nuclear conflict in Saussurea,and a phylogeny based on nuclear data is more suitable than one based on chloroplast data for exploring the infrageneric classification of Saussurea.Based on the nuclear phylogeny obtained and morphological characters,we proposed a revised infrageneric taxonomy of Saussurea,which includes four subgenera and 13 sections.Specifically,1)S.sect.Cincta,S.sect.Gymnocline,S.sect.Lagurostemon,and S.sect.Strictae were moved from S.subg.Saussurea to S.subg.Amphilaena,2)S.sect.Pseudoeriocoryne was moved from S.subg.Eriocoryne to S.subg.Amphilaena,and 3)S.sect.Laguranthera was moved from S.subg.Saussurea to S.subg.Theodorea.
基金funded by the National Natural Science Foundation of China(Grant No.31970232)the National Key Basic Research Program of China(Grant No.2014CB954100).
文摘Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized genera.Recognition and delineation of genera within this family have varied greatly.The three-subfamily classification of Dryopteridaceae was based primarily on molecular phylogenetic relationships but lacked morphological evidence,and the phylogenetic relationships of the subfamilies and genera of Dryopteridaceae are only partially resolved.A comprehensive and robust phylogeny is urgently needed.The heterogeneous morphology of the current members of Dryopteridaceae makes the family and its subfamilies difficult to define by single morphological characteristics or even character combinations.We carried out phylogenetic analyses to reconstruct a highly supported phylogeny of Dryopteridaceae.Our analyses recovered 24 strongly supported clades grouped into seven major clades of Dryopteridaceae.Seven morphological characters including habit,rhizome shape,frond morphology,rachis-costae architecture,appendages on stipe base and lamina,and soral arrangement were found to be informative for identifying different major clades and clades in Dryopteridaceae.Based on phylogenetic reconstruction and morphological analysis,we presented an updated infra-familial classification of Dryopteridaceae with seven subfamilies and 24 genera including four newly proposed subfamilies(Ctenitidoideae,Lastreopsidoideae,Pleocnemioideae,and Polystichopsidoideae).Morphological character combinations of each subfamily are summarized,and a key is provided.Most genera sensu PPG I are recognized,with Stigmatopetris reclassified into Dryopteridoideae and Arthrobotrya considered a synonym of Teratophyllum.A new genus Pseudarachniodes is introduced.This revised classification will serve as a foundational framework for future investigations on taxonomy,biogeography,and diversification of the most species-rich Dryopteridaceae in ferns.
基金supported by funds from the Eberly College of Sciences and the Huck Institutes of the Life Sciences at the Pennsylvania State University。
文摘Angiosperms(flowering plants) are by far the most diverse land plant group with over 300,000 species. The sudden appearance of diverse angiosperms in the fossil record was referred to by Darwin as the “abominable mystery,”hence contributing to the heightened interest in angiosperm evolution. Angiosperms display wide ranges of morphological, physiological,and ecological characters, some of which have probably influenced their species richness. The evolutionary analyses of these characteristics help to address questions of angiosperm diversification and require well resolved phylogeny. Following the great successes of phylogenetic analyses using plastid sequences,dozens to thousands of nuclear genes from next-generation sequencing have been used in angiosperm phylogenomic analyses, providing well resolved phylogenies and new insights into the evolution of angiosperms. In this review we focus on recent nuclear phylogenomic analyses of large angiosperm clades, orders, families,and subdivisions of some families and provide a summarized Nuclear Phylogenetic Tree of Angiosperm Families. The newly established nuclear phylogenetic relationships are highlighted and compared with previous phylogenetic results. The sequenced genomes of Amborella,Nymphaea, Chloranthus, Ceratophyllum, and species of monocots, Magnoliids, and basal eudicots, have facilitated the phylogenomics of relationships among five major angiosperms clades. All but one of the 64 angiosperm orders were included in nuclear phylogenomics with well resolved relationships except the placements of several orders. Most families have been included with robust and highly supported placements, especially for relationships within several large and important orders and families.Additionally, we examine the divergence time estimation and biogeographic analyses of angiosperm on the basis of the nuclear phylogenomic frameworks and discuss the differences compared with previous analyses. Furthermore,we discuss the implications of nuclear phylogenomic analyses on ancestral reconstruction of morphological, physiological, and ecological characters of angiosperm groups, limitations of current nuclear phylogenomic studies, and the taxa that require future attention.
基金supported by the National Natural Science Foundation of China (32022006)the Program for Guangdong"ZhuJiang"Innovation Teams (2019ZT08N628)+6 种基金the Agricultural Science and Technology Innovation Program (ASTIP) (CAAS-XTCX2016001)the special funds for science technology innovation and industrial development of Shenzhen Dapeng New District (PT202101-01)supported by the National Natural Science Foundation of China (32070250)the Natural Science Foundation of Guangdong Province (2020A1515011030)the open research project of"Cross-Cooperative Team"of the Germplasm Bank of Wild Species,Kunming Institute of Botany,Chinese Academy of Sciencessupported by the Natural Science Foundation of Guangdong Province (2022A1515110240)support was provided by IRD and the Agence Nationale de la Recherche (Project SESAM,2010 BLAN 170801).
文摘Plant root-nodule symbiosis(RNS)with mutualistic nitrogen-fixing bacteria is restricted to a single clade of angiosperms,the Nitrogen-Fixing Nodulation Clade(NFNC),and is best understood in the legume family.Nodulating species share many commonalities,explained either by divergence from a common ancestor over 100 million years ago or by convergence following independent origins over that same time period.Regardless,comparative analyses of diverse nodulation syndromes can provide insights into constraints on nodulation—what must be acquired or cannot be lost for a functional symbiosis—and the latitude for Plant Communications Genomic landscape of nodulation variation in the symbiosis.However,much remains to be learned about nodulation,especially outside of legumes.Here,we employed a large-scale phylogenomic analysis across 88 species,complemented by 151 RNA-seq libraries,to elucidate the evolution of RNS.Our phylogenomic analyses further emphasize the uniqueness of the transcription factor NIN as a master regulator of nodulation and identify key muta-tions that affect its function across the NFNC.Comparative transcriptomic assessment revealed nodule-specific upregulated genes across diverse nodulating plants,while also identifying nodule-specific and nitrogen-response genes.Approximately 70%of symbiosis-related genes are highly conserved in the four representative species,whereas defense-related and host-range restriction genes tend to be lineage specific.Our study also identified over 900000 conserved non-coding elements(CNEs),over 300000 of which are unique to sampled NFNC species.NFNC-specific CNEs are enriched with the active H3K9ac mark and are correlated with accessible chromatin regions,thus representing a pool of candidate regula-tory elements for genes involved in RNS.Collectively,our results provide novel insights into the evolution of nodulation and lay a foundation for engineering of RNS traits in agriculturally important crops.
基金US National Science Foundation(NSF)DEB 1737898(GB and NVP),Michigan State University AgBioResearch NIFA project MICL02416(GB),NSF STC BEACON Cooperative Agreement DBI-093954(GB&NVP)US National Science Foundation(The Zygomycetes Genealogy of Life)DEB1354802 and DEB1441677(JS)+1 种基金JGI-the work conducted by the U.S.Department of Energy Joint Genome Institute,a DOE Office of Science User Facility,is supported by the Office of Science of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231Data analyses were performed on the High-Performance Computing Cluster at the University of California-Riverside in the Institute of Integrative Genome Biology supported by NSF DBI-1429826 and NIH S10-OD016290(JS).
文摘Early efforts to classify Mortierellaceae were based on macro-and micromorphology,but sequencing and phylogenetic studies with ribosomal DNA(rDNA)markers have demonstrated conflicting taxonomic groupings and polyphyletic genera.Although some taxonomic confusion in the family has been clarified,rDNA data alone is unable to resolve higher level phylogenetic relationships within Mortierellaceae.In this study,we applied two parallel approaches to resolve the Mortierel-laceae phylogeny:low coverage genome(LCG)sequencing and high-throughput,multiplexed targeted amplicon sequenc-ing to generate sequence data for multi-gene phylogenetics.We then combined our datasets to provide a well-supported genome-based phylogeny having broad sampling depth from the amplicon dataset.Resolving the Mortierellaceae phylogeny into monophyletic genera resulted in 13 genera,7 of which are newly proposed.Low-coverage genome sequencing proved to be a relatively cost-effective means of generating a high-confidence phylogeny.The multi-gene phylogenetics approach enabled much greater sampling depth and breadth than the LCG approach,but has limitations too.We present this work to resolve some of the taxonomic confusion and provide a genus-level framework to empower future studies on Mortierellaceae diversity and evolution.
基金This work was supported by the Natural Science Foundation of China （Grant Nos. 31430077, 91131013, and 31272285）. Many thanks are given to Prof. Weibo Song （Ocean University of China）, for his indispensable advice during the preparation of the manuscript.
文摘Ciliates are one of the oldest living eukaryotic unicellular organisms, widely distributed in the waters around the world. As a typical marine oligotrich ciliate, Strombidium sulcatum plays an important role in marine food webs and energy flow. Here we report the first deep se- quencing and analyses of RNA-Seq data from Strombidium sulcatum. We generated 42,640 unigenes with an N50 of 1,451 bp after de novo assembly and removing rRNA, mitochondrial and bacteria contaminants. We employed SPOCS to detect orthologs from S. sulcatum and 17 other ciliates, and then carried out the phyloge- nomic reconstruction using 127 single copy orthologs. In phylogenomic analyses, concatenated trees have similar topological structures with concordance tree on the class level. Together with phylogenetic networks analysis, it aroused more doubts about the placement of Protocruzia, Mesodinium and Myrionecta. While epi- plasmic proteins are known to be related to morphological characteristics, we found the potential relationship between gene expression of epiplasmic proteins and morphological characteristics. This work supports the use of high throughput approaches for phylogenomic analysis as well as correlation analysis between expression level of target genes and morphological characteristics.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)the National Natural Science Foundation of China(32200193).
文摘Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow distribution.Previous phylogenetic studies revealed an unexpected,isolated phylogenetic position of Ps.gracilis.Here we conducted phylogenomic analysis by sampling populations of Ps.gracilis and its sympatric species Ps.nanunica and Sinosasa polytricha reflecting different genomic signals,by deep genome skimming.Integrating molecular evidence from chloroplast genes and genome-wide SNPs,we deciphered the phylogenetic relationships of Ps.gracilis.Both plastid and nuclear data indicate that Ps.gracilis is more closely related to Sinosasa,which is discordant with the taxonomic treatment.To further explore this molecular-morphological conflict,we screened 411“perfect-copy”syntenic genes to reconstruct phylogenies using both the concatenation and coalescent methods.We observed extensive discordance between gene trees and the putative species tree.A significant hybridization event was detected based on 411 genes from the D subgenome,showing Ps.gracilis was a hybrid descendant between Sinosasa longiligulata and Ps.nanunica,with 63.56%and 36.44%inheritance probabilities of each parent.Moreover,introgression events were detected in the C subgenome between Ps.gracilis and S.polytricha in the same distribution region.Our findings suggest that sympatric hybridization and introgression play a crucial role in the origin of Ps.gracilis.By providing an empirical example of bamboo of hybrid origin using comprehensive analyses based on genomic data from different inheritance systems and morphological characters,our study represents a step forward in understanding of reticulate evolution of bamboos.
文摘Laurasiatheria is one of the richest and most diverse superorders of placental mammals. Because this group had a rapid evolutionary radiation, the phylogenetic relationships among the six orders of Laurasiatheria remain a subject of heated debate and several issues related to its phylogeny remain open. Reconstructing the true phylogenetic relationships of Laurasiatheria is a significant case study in evolutionary biology due to the diversity of this suborder and such research will have significant implications for biodiversity conservation. We review the higher-level （inter-ordinal） phylogenies of Laurasiatheria based on previous cytogenetic, morphological and molecular data, and discuss the controversies of its phylogenetic relationship. This review aims to outline future researches on Laurasiatheria phylogeny and adaptive evolution.
基金supported by the Talents Team Construction Fund of Northwestern Polytechnical University(NWPU)Strategic Priority Research Program of CAS(XDB13000000)to W.W.State Key Laboratory of Genetic Resources and Evolution,Kunming Institute of Zoology,Chinese Academy of Sciences(GREKF19-11 to L.C.)
文摘Ruminants(Ruminantia) are among the most successful herbivorous mammals, exhibiting wideranging morphological and ecological characteristics(such as headgear and multichambered stomach)and including various key livestock species(e. g.,cattle, buffalo, yak, sheep, and goat). Understanding their evolution is of great significance not only in scientific research but also in applications potential for human society. The rapid growth of genomic resources provides unprecedented opportunities to dissect the evolutionary histories and molecular mechanisms underlying the distinct characteristics of ruminants. Here we summarize our current understanding of the genetic, morphological, and ecological diversity of ruminants and provide prospects for future studies.
基金financially supported by the Major Program of National Natural Science Foundation of China (No. 31590823)the National Natural Science Foundation of China (No. 31070297)
文摘Panax stipuleanatus(Araliaceae) is an endangered and medicinally important plant endemic to China.However, phylogenetic relationships within the genus Panax have remained unclear. In this study, we sequenced the complete plastome of P. stipuleanatus and included previously reported Panax plastomes to better understand the relationships between species and plastome evolution within the genus Panax.The plastome of P. stipuleanatus is 156,069 base pairs(bp) in length, consisting of a pair of inverted repeats(IRs, each 25,887 bp) that divide the plastome into a large single copy region(LSC, 86,126 bp) and a small single copy region(SSC, 8169 bp). The plastome contains 114 unigenes(80 protein-coding genes,30 tRNA genes, and 4 r RNA genes). Comparative analyses indicated that the plastome gene content and order, as well as the expansion/contraction of the IR regions, are all highly conserved within Panax. No significant positive selection in the plastid protein-coding genes was observed across the eight Panax species, suggesting the Panax plastomes may have undergone a strong purifying selection. Our phylogenomic analyses resulted in a phylogeny with high resolution and supports for Panax. Nine proteincoding genes and 10 non-coding regions presented high sequence divergence, which could be useful for identifying different Panax species.
基金supported by grants from the National Natural Science Foundation of Chinakey international (regional) cooperative research project (31720103903)The Strategic Priority Research Program of the Chinese Academy of Sciences (XDPB0201)
文摘Cannabaceae is an economically important family that includes ten genera and ca. 117 accepted species.To explore the structure and size variation of their plastomes, we sequenced ten plastomes representing all ten genera of Cannabaceae. Each plastome possessed the typical angiosperm quadripartite structure and contained a total of 128 genes. The Inverted Repeat(IR) regions in five plastomes had experienced small expansions(330 e983 bp) into the Large Single-Copy(LSC) region. The plastome of Chaetachme aristata has experienced a 942-bp IR contraction and lost rpl22 and rps19 in its IRs. The substitution rates of rps19 and rpl22 decreased after they shifted from the LSC to IR. A 270-bp inversion was detected in the Parasponia rugosa plastome, which might have been mediated by 18-bp inverted repeats. Repeat sequences, simple sequence repeats, and nucleotide substitution rates varied among these plastomes.Molecular markers with more than 13% variable sites and 5% parsimony-informative sites were identified, which may be useful for further phylogenetic analysis and species identification. Our results show strong support for a sister relationship between Gironniera and Lozanell(BS ? 100). Celtis, CannabisHumulus, Chaetachme-Pteroceltis, and Trema-Parasponia formed a strongly supported clade, and their relationships were well resolved with strong support(BS ? 100). The availability of these ten plastomes provides valuable genetic information for accurately identifying species, clarifying taxonomy and reconstructing the intergeneric phylogeny of Cannabaceae.
基金Supported by the National Natural Science Foundation of China(Nos.41006082,31372517)
文摘Cobetia marina is a model proteobacteria in researches on marine biofouling. Its taxonomic nomenclature has been revised many times over the past few decades. To better understand the role of the surface-associated lifestyle of C. marina and the phylogeny of the family Halomonadaceae, we sequenced the entire genome of C. marina JCM 21022T using single molecule real-time sequencing technology （SMRT） and performed comparative genomics and phylogenomics analyses. The circular chromosome was 4 176 300 bp with an average GC content of 62.44% and contained 3 611 predicted coding sequences, 72 tRNA genes, and 21 rRNA genes. The C. marina JCM 2102U genome contained a set of crucial genes involved in surface colonization processes. The comparative genome analysis indicated the significant differences between C. marina JCM 21022T and Cobetia amphilecti KMM 296 （formerly named C. marina KMM 296） resulted from sequence insertions or deletions and chromosomal recombination. Despite these differences, pan and core genome analysis showed similar gene functions between the two strains. The phylogenomic study of the family Halomonadaceae is relationships were well resolved among every genera Cobetia, Kushneria, Zymobacter, and Halotalea. reported here for the first time. We found that the tested, including Chromohalobacter, Halomonas,
基金funded by the National Natural Science Foundation of China (Grant no.32070223)the Biological Resources Programme,Chinese Academy of Sciences (Grant no.KFJ-BRP-017-19)
文摘Previous studies recognized three major lineages of the family Costaceae:a South American clade,an Asian clade and a Costus clade.However,the genus Hellenia within the Asian clade has been shown to be non-monophyletic and its morphology has not been studied carefully.Therefore,the complete plastid genomes of Hellenia species were obtained and the monophyly of Hellenia was tested through four different datasets in this study.Plastid phylogenomic analyses of Costaceae revealed that Hellenia is strongly supported as paraphyletic.Two major clades are recovered,namely the Hellenia s.s.subclade and the Parahellenia subclade.Phylogenetic analyses based on an enlarged taxon sampling of the Asian clade using a two chloroplast markers dataset(trnK intron and trnL-F spacer)confirmed the paraphyly of Hellenia.Meanwhile,morphological analyses suggested that members of the Parahellenia subclade differ from the remaining Hellenia species in many characters including inflorescences,bracts,stigma,axillary buds,floral tubes and labellum.According to the present molecular and morphological evidence,the latter subclade is recognized as a new genus,Parahellenia.Two new species are described,four new combinations are made,and identification keys are also provided.
基金Program for New Century Excellent Talents in University(NCET)。
文摘Laurasiatheria is one of the richest and most diverse superorders of placental mammals.Because this group had a rapid evolutionary radiation,the phylogenetic relationships among the six orders of Laurasiatheria remain a subject of heated debate and several issues related to its phylogeny remain open.Reconstructing the true phylogenetic relationships of Laurasiatheria is a significant case study in evolutionary biology due to the diversity of this suborder and such research will have significant implications for biodiversity conservation.We review the higher-level(inter-ordinal)phylogenies of Laurasiatheria based on previous cytogenetic,morphological and molecular data,and discuss the controversies of its phylogenetic relationship.This review aims to outline future researches on Laurasiatheria phylogeny and adaptive evolution.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA19050404)National Natural Science Foundation of China(No.31800174).
文摘Lycophytes are an ancient clade of the non-flowering vascular plants with chromosome numbers that vary from tens to hundreds.They are an excellent study system for examining whole-genome duplications(WGDs),or polyploidization,in spore-dispersed vascular plants.However,a lack of genome sequence data limits the reliable detection of very ancient WGDs,small-scale duplications(SSDs),and recent WGDs.Here,we integrated phylogenomic analysis and the distribution of synonymous substitutions per synonymous sites(Ks)of the transcriptomes of 13 species of lycophytes to identify,locate,and date multiple WGDs in the lycophyte family Lycopodiaceae.Additionally,we examined the genus Phlegmariurus for signs of genetic discordance,which can provide valuable insight into the underlying causes of such conflict(e.g.,hybridization,incomplete lineage sorting,or horizontal gene transfer).We found strong evidence that two WGD events occurred along the phylogenetic backbone of Lycopodiaceae,with one occurring in the common ancestor of extant Phlegmariurus(Lycopodiaceae)approximately 22-23 million years ago(Mya)and the other occurring in the common ancestor of Lycopodiaceae around 206-214 Mya.Interestingly,we found significant genetic discordance in the genus Phlegmariurus,indicating that the genus has a complex evolutionary history.This study provides molecular evidence for multiple WGDs in Lycopodiaceae and offers phylogenetic clues to the evolutionary history of Lycopodiaceae.
基金We thank Dr.Peng-Fei Ma for improving the manuscript.We also thank the two anonymous reviewers for their constructive comments and suggestions.The study was supported by the Strategic Priority Research Program,Chinese Academy of Sciences,China(XDB 31000000)the National Natural Science Foundation of China(31970232)+1 种基金the Large-scale Scientific Facilities of the Chinese Academy of Sciences,China(2017-LSF-GBOWS-02)the technological leading talent project of Yunnan,China(2017HA014).
文摘Cytidine-to-uridine(C-to-U)RNA editing is common in coding regions of organellar genomes throughout land plants.In most cases RNA editing alters translated amino acids or creates new start codons,potentially confounds phylogenetic reconstructions.In this study,we used the spike moss genus Selaginella(lycophytes),which has the highest frequency of RNA editing,as a model to test the effects of extreme RNA editing on phylogenetic reconstruction.We predicted the C-to-U RNA editing sites in coding regions of 18 Selaginella plastomes,and reconstructed the phylogenetic relationships within Selaginella based on three data set pairs consisted of plastome or RNA-edited coding sequences,first and second codon positions,and translated amino acid sequences,respectively.We predicted between 400 and 3100 RNA editing sites of 18 Selaginella plastomes.The numbers of RNA editing sites in plastomes were highly correlated with the GC content of first and second codon positions,but not correlated with the GC content of plastomes as a whole.Contrast phylogenetic analyses showed that there were substantial differences(e.g.,the placement of clade B in Selaginella)between the phylogenies generated by the plastome and RNA-edited data sets.This empirical study provides evidence that extreme C-to-U RNA editing in the coding regions of organellar genomes alters the sequences used for phylogenetic reconstruction,and might even confound phylogenetic reconstruction.Therefore,RNA editing sites should be corrected when plastid or mitochondrial genes are used for phylogenetic studies,particularly in those lineages with abundant organellar RNA editing sites,such as hornworts,quillworts,spike mosses,and some seed plants.
