Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco popula...Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco populations have grown.These native camelids share habitat and diets with sheep,but their effect on vegetation is poorly understood and has long been debated.We set up an exclusion experiment in Monte León and Cañadón Vaca,a semiarid shrubland grassland in southern Patagonia,currently grazed only by guanacos.Vegetation baselines were studied in 2016 in twelve plots,and half of them were protected from guanaco grazing.Thirty-six plots were cleared to study revegetation.Vegetation was reassessed in 2021,and changes were evaluated using a paired t-test.Within protected plots,vegetation cover increased,bare soil diminished,and vegetated patches grew in size,but the density of the patch-interpatch arrangement did not change.Biodiversity,measured by richness and the Shan-non-Wiener(SW)index,grew significantly.Nutrient recycling increased,as did the Stability and Infiltration Land Function indexes,although these last differences were not significant.Vegetation cover under guanaco grazing also increased,mainly due to the growth of dwarf shrubs,a typical tendency in sheep grazing-induced transitions in the region.Vegetated patches under grazing fragmented,resulting in smaller patches and denser patch struc-tures,while diversity and land function indexes remained unchanged.Young plants established in cleared plots without guanacos showed higher cover density and individual size.These effects are similar to those observed in numerous experimental sheep exclosures.Guanaco grazing may thus prevent restoration and contribute to the generalized land degradation processes that overgrazing has been causing in Patagonia for over a century.展开更多
Among multiple sclerosis(MS)susceptibility genes,the strongest non-human leukocyte antigen(HLA)signal in the Italian population maps to the TNFSF14 gene encoding LIGHT,a glycoprotein involved in dendritic cell(DC)matu...Among multiple sclerosis(MS)susceptibility genes,the strongest non-human leukocyte antigen(HLA)signal in the Italian population maps to the TNFSF14 gene encoding LIGHT,a glycoprotein involved in dendritic cell(DC)maturation.Through fine-mapping in a large Italian dataset(4,198 patients with MS and3,903 controls),we show that the TNFSF14 intronic SNP rs1077667 is the primarily MS-associated variant in the region.Expression quantitative trait locus(e QTL)analysis indicates that the MS risk allele is significantly associated with reduced TNFSF14 messenger RNA levels in blood cells,which is consistent with the allelic imbalance in RNA-Seq reads(P<0.0001).The MS risk allele is associated with reduced levels of TNFSF14 gene expression(P<0.01)in blood cells from 84 Italian patients with MS and 80 healthy controls(HCs).Interestingly,patients with MS are lower expressors of TNFSF14 compared to HC(P<0.007).Individuals homozygous for the MS risk allele display an increased percentage of LIGHT-positive peripheral blood myeloid DCs(CD11 c+,P=0.035)in 37 HCs,as well as in in vitro monocyte-derived DCs from 22 HCs(P=0.04).Our findings suggest that the intronic variant rs1077667 alters the expression of TNFSF14 in immune cells,which may play a role in MS pathogenesis.展开更多
基金Resources for this study were obtained from INTA Projects.
文摘Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco populations have grown.These native camelids share habitat and diets with sheep,but their effect on vegetation is poorly understood and has long been debated.We set up an exclusion experiment in Monte León and Cañadón Vaca,a semiarid shrubland grassland in southern Patagonia,currently grazed only by guanacos.Vegetation baselines were studied in 2016 in twelve plots,and half of them were protected from guanaco grazing.Thirty-six plots were cleared to study revegetation.Vegetation was reassessed in 2021,and changes were evaluated using a paired t-test.Within protected plots,vegetation cover increased,bare soil diminished,and vegetated patches grew in size,but the density of the patch-interpatch arrangement did not change.Biodiversity,measured by richness and the Shan-non-Wiener(SW)index,grew significantly.Nutrient recycling increased,as did the Stability and Infiltration Land Function indexes,although these last differences were not significant.Vegetation cover under guanaco grazing also increased,mainly due to the growth of dwarf shrubs,a typical tendency in sheep grazing-induced transitions in the region.Vegetated patches under grazing fragmented,resulting in smaller patches and denser patch struc-tures,while diversity and land function indexes remained unchanged.Young plants established in cleared plots without guanacos showed higher cover density and individual size.These effects are similar to those observed in numerous experimental sheep exclosures.Guanaco grazing may thus prevent restoration and contribute to the generalized land degradation processes that overgrazing has been causing in Patagonia for over a century.
基金supported by the Italian Foundation of Multiple Sclerosis(FISM,2011/R/142015/R/10,2019/R-Multi/033)by the Italian Ministry of Health(RF-2016-02361294)the AGING Project for Department of Excellence at the Department of Translational Medicine(DIMET),Universitàdel Piemonte Orientale,Novara,Italy+1 种基金supported by Consorzio Interuniversitario di Biotecnologie(CIB)partially supported by Multiple MS project(Horizon 2020 European Grant 733161),Stockholm。
文摘Among multiple sclerosis(MS)susceptibility genes,the strongest non-human leukocyte antigen(HLA)signal in the Italian population maps to the TNFSF14 gene encoding LIGHT,a glycoprotein involved in dendritic cell(DC)maturation.Through fine-mapping in a large Italian dataset(4,198 patients with MS and3,903 controls),we show that the TNFSF14 intronic SNP rs1077667 is the primarily MS-associated variant in the region.Expression quantitative trait locus(e QTL)analysis indicates that the MS risk allele is significantly associated with reduced TNFSF14 messenger RNA levels in blood cells,which is consistent with the allelic imbalance in RNA-Seq reads(P<0.0001).The MS risk allele is associated with reduced levels of TNFSF14 gene expression(P<0.01)in blood cells from 84 Italian patients with MS and 80 healthy controls(HCs).Interestingly,patients with MS are lower expressors of TNFSF14 compared to HC(P<0.007).Individuals homozygous for the MS risk allele display an increased percentage of LIGHT-positive peripheral blood myeloid DCs(CD11 c+,P=0.035)in 37 HCs,as well as in in vitro monocyte-derived DCs from 22 HCs(P=0.04).Our findings suggest that the intronic variant rs1077667 alters the expression of TNFSF14 in immune cells,which may play a role in MS pathogenesis.
