Gene expression regulation, including loss-of-function and gain-of-function assays, is a powerful method to study developmental and disease mechanisms. Drosophila melanogaster is an ideal model system particularly wel...Gene expression regulation, including loss-of-function and gain-of-function assays, is a powerful method to study developmental and disease mechanisms. Drosophila melanogaster is an ideal model system particularly well-equipped with many genetic tools. In this review, we describe and discuss the gene expression regulation techniques recently developed and their applications, including the CRISPR/Cas9-triggered heritable mutation system, CRISPR/dCas9-based transcriptional activation(CRISPRa) system,and CRISPR/dCas9-based transcriptional repression(CRISPRi) system, as well as the next-generation transgenic RNAi system. The main purpose of this review is to provide the fly research community with an updated summary of newly developed gene expression regulation techniques and help the community to select appropriate methods and optimize the research strategy.展开更多
In the Drosophila ovary, escort cells (ECs) extrinsically control germline stem cell (GSC) maintenance and progeny differentiation. However, the underlying mechanisms remain poorly understood. In this study,we identif...In the Drosophila ovary, escort cells (ECs) extrinsically control germline stem cell (GSC) maintenance and progeny differentiation. However, the underlying mechanisms remain poorly understood. In this study,we identified 173 EC genes for their roles in controlling GSC maintenance and progeny differentiation by using an in vivo systematic RNAi approach. Of the identified genes, 10 and 163 are required in ECs to promote GSC maintenance and progeny differentiation, respectively. The genes required for progeny differentiation fall into different functional categories, including transcription, mRNA splicing, protein degradation, signal transduction and cytoskeleton regulation. In addition, the GSC progeny differentiation defects caused by defective ECs are often associated with BMP signaling elevation, indicating that preventing BMP signaling is a general functional feature of the differentiation niche. Lastly, exon junction complex (EJC) components, which are essential for mRNA splicing, are required in ECs to promote GSC progeny differentiation by maintaining ECs and preventing BMP signaling. Therefore, this study has identified the major regulators of the differentiation niche, which provides important insights into how stem cell progeny differentiation is extrinsically controlled.展开更多
Sense mutations in several conserved modifiable sites of histone H3 have been found to be strongly correlated with multiple tissuespecific clinical cancers.These clinical site mutants acquire a distinctively new epige...Sense mutations in several conserved modifiable sites of histone H3 have been found to be strongly correlated with multiple tissuespecific clinical cancers.These clinical site mutants acquire a distinctively new epigenetic role and mediate cancer evolution.In this study,we mimicked histone H3 at the 56th lysine(H3K56)mutant incorporation in mouse embryonic stem cells(mESCs)by lentivirus-mediated ectopic expression and analyzed the effects on replication and epigenetic regulation.The data show that two types of H3K56 mutants,namely H3 lysine 56-to-methionine(H3K56M)and H3 lysine 56-to-alanine(H3K56A),promote replication by recruiting more minichromosome maintenance complex component 3 and checkpoint kinase 1 onto chromatin compared with wild-type histone H3 and other site substitution mutants.Under this condition,the frequency of genomic copy number gain in H3K56M and H3K56A cells globally increases,especially in the Mycl1 region,a known molecular marker frequently occurring in multiple malignant cancers.Additionally,we found the disruption of H3K56 acetylation distribution in the copy-gain regions,which indicates a probable epigenetic mechanism of H3K56M and H3K56A.We then identified that H3K56M and H3K56A can trigger a potential adaptation to transcription;genes involved in the mitogen-activated protein kinase pathway are partially upregulated,whereas genes associated with intrinsic apoptotic function show obvious downregulation.The final outcome of ectopic H3K56M and H3K56A incorporation in mESCs is an enhanced ability to form carcinomas.This work indicates that H3K56 site conservation and proper modification play important roles in harmonizing the function of the replication machinery in mESCs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31571320,31872818,and 31801079)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2016YFE0113700)the China Postdoctoral Science Foundation(2017M620747)
文摘Gene expression regulation, including loss-of-function and gain-of-function assays, is a powerful method to study developmental and disease mechanisms. Drosophila melanogaster is an ideal model system particularly well-equipped with many genetic tools. In this review, we describe and discuss the gene expression regulation techniques recently developed and their applications, including the CRISPR/Cas9-triggered heritable mutation system, CRISPR/dCas9-based transcriptional activation(CRISPRa) system,and CRISPR/dCas9-based transcriptional repression(CRISPRi) system, as well as the next-generation transgenic RNAi system. The main purpose of this review is to provide the fly research community with an updated summary of newly developed gene expression regulation techniques and help the community to select appropriate methods and optimize the research strategy.
基金supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of the People's Republic of China (2016YFE0113700)the National Natural Science Foundation of China (31571320, 31872818, and 31801079)
文摘In the Drosophila ovary, escort cells (ECs) extrinsically control germline stem cell (GSC) maintenance and progeny differentiation. However, the underlying mechanisms remain poorly understood. In this study,we identified 173 EC genes for their roles in controlling GSC maintenance and progeny differentiation by using an in vivo systematic RNAi approach. Of the identified genes, 10 and 163 are required in ECs to promote GSC maintenance and progeny differentiation, respectively. The genes required for progeny differentiation fall into different functional categories, including transcription, mRNA splicing, protein degradation, signal transduction and cytoskeleton regulation. In addition, the GSC progeny differentiation defects caused by defective ECs are often associated with BMP signaling elevation, indicating that preventing BMP signaling is a general functional feature of the differentiation niche. Lastly, exon junction complex (EJC) components, which are essential for mRNA splicing, are required in ECs to promote GSC progeny differentiation by maintaining ECs and preventing BMP signaling. Therefore, this study has identified the major regulators of the differentiation niche, which provides important insights into how stem cell progeny differentiation is extrinsically controlled.
基金supported by grants from the National Key Research and Development Program of China(2017YFA0103301)the National Natural Science Foundation of China(81972743)China Postdoctoral Science Foundation(2020M671205).
文摘Sense mutations in several conserved modifiable sites of histone H3 have been found to be strongly correlated with multiple tissuespecific clinical cancers.These clinical site mutants acquire a distinctively new epigenetic role and mediate cancer evolution.In this study,we mimicked histone H3 at the 56th lysine(H3K56)mutant incorporation in mouse embryonic stem cells(mESCs)by lentivirus-mediated ectopic expression and analyzed the effects on replication and epigenetic regulation.The data show that two types of H3K56 mutants,namely H3 lysine 56-to-methionine(H3K56M)and H3 lysine 56-to-alanine(H3K56A),promote replication by recruiting more minichromosome maintenance complex component 3 and checkpoint kinase 1 onto chromatin compared with wild-type histone H3 and other site substitution mutants.Under this condition,the frequency of genomic copy number gain in H3K56M and H3K56A cells globally increases,especially in the Mycl1 region,a known molecular marker frequently occurring in multiple malignant cancers.Additionally,we found the disruption of H3K56 acetylation distribution in the copy-gain regions,which indicates a probable epigenetic mechanism of H3K56M and H3K56A.We then identified that H3K56M and H3K56A can trigger a potential adaptation to transcription;genes involved in the mitogen-activated protein kinase pathway are partially upregulated,whereas genes associated with intrinsic apoptotic function show obvious downregulation.The final outcome of ectopic H3K56M and H3K56A incorporation in mESCs is an enhanced ability to form carcinomas.This work indicates that H3K56 site conservation and proper modification play important roles in harmonizing the function of the replication machinery in mESCs.
