U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb ...U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb zircon analyses of two samples from the investigated mafic dykes yield consistent ages ranging from 121.9 Ma ± 0.47 Ma to 122.9 Ma ± 0.61 Ma. The mafic dykes are characterized by high （87Sr/86Sr） i ranging from 0.7087 to 0.7089, low εNd（t） values ranging from -16.9 to -17.8, 206Pb/204Pb = 17.15 to 17.17, 207Pb/204Pb = 15.45 to 15.47, and 208Pb/204Pb = 37.59 to 37.68. Results from the current study suggest that the mafic dykes are derived from partial melting of ancient lithospheric mantle that was variably hybridized by melts derived from foundered lower crustal eclogite. The mafic dykes may have been generated through subsequent insignificant crystal fractionation and very minor crustal contamination during magma ascent. Combined with previous studies, the current findings provide new evidence that the intense lithospheric thinning beneath the eastern Shandong Province of eastern China occurred at ~120 Ma, and that this condition was caused by the removal of the lower lithosphere （mantle and lower crust）.展开更多
Controlled pedigrees and the multi-decade timescale of national crop plant breeding programs offer a unique experimental context for examining how selection affects plant genomes.More than 3000 wheat cultivars have be...Controlled pedigrees and the multi-decade timescale of national crop plant breeding programs offer a unique experimental context for examining how selection affects plant genomes.More than 3000 wheat cultivars have been registered,released,and documented since 1949 in China.In this study,a set of 145 elite cultivars selected from historical points of wheat breeding in China were re-sequenced.A total of 43.75 Tb of sequence data were generated with an average read depth of 17.94x for each cultivar,and more than 60.92 million SNPs and 2.54 million InDels were captured,based on the Chinese Spring RefSeq genome v1.0.Seventy years of breeder-driven selection led to dramatic changes in grain yield and related phenotypes,with distinct genomic regions and phenotypes tar-geted by different breeders across the decades.There are very clear instances illustrating how introduced Italian and otherforeign germplasm was integrated into Chinese wheat programs and reshaped the genomic landscape of local modern cultivars.Importantly,the resequencing data also highlighted significant asymmetric breeding selec-tion among the three sub-genomes:this was evident in both the collinear blocks for homeologous chromosomes and among sets of three homeologous genes.Accumulation of more newly assembled genes in newer cultivars implied the potential value of these genes in breeding.Conserved and extended sharing of linkage disequilibrium(LD)blocks was highlighted among pedigree-related cultivars,in which fewer haplotype differences were detected.Fixation or replacement of haplotypes from founder genotypes after generations of breeding was related to their breeding value.Based on the haplotype frequency changes in LD blocks of pedigree-related cultivars,we propose a strategy for evaluating the breeding value of any given line on the basis of the accumulation(pyramiding)of bene-ficial haplotypes.Collectively,our study demonstrates the influence of "founder genotypes" on the output of breeding efforts over many decades and also suggests that found展开更多
Since late 2011,outbreaks of pseudorabies virus(PRV)have occurred in southern China causing major economic losses to the pig industry.We previously reported that variant PRV forms and recombination in China could be t...Since late 2011,outbreaks of pseudorabies virus(PRV)have occurred in southern China causing major economic losses to the pig industry.We previously reported that variant PRV forms and recombination in China could be the source of continued epidemics.Here,we analyzed samples from intensive pig farms in eastern China between 2017 and 2019,and sequenced the main glycoproteins(gB,gC,gD,and gE)to study the evolution characteristics of PRV.Based on the gC gene,we found that PRV variants belong to clade 2 and detected a founder effect during by the PRV epidemic.In addition,we detected inter-and intra-clade recombination;in particular,inter-clade recombination in the gB genes of strains FJ-ZXF and FJ-W2,which were recombinant with clade 1 strains.We also found specific amino-acid changes and positively selected sites,possibly associated with functional changes.This analysis of the emergence of PRV in China illustrates the need for continuous monitoring and the development of vaccines against specific variants of PRV.展开更多
基金supported by the Opening Project of the State Key Laboratory of Ore deposit Geochemistry(201206)National Natural Science Foundation of China(41373028,41573022)
基金supported by Opening Project(201206)of the State Key Laboratory of Ore deposit Geochemistry,Chinese Academia of Sciencesthe National Nature Science Foundation of China(40773020,40972071,90714010,and 40634020)
文摘U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb zircon analyses of two samples from the investigated mafic dykes yield consistent ages ranging from 121.9 Ma ± 0.47 Ma to 122.9 Ma ± 0.61 Ma. The mafic dykes are characterized by high （87Sr/86Sr） i ranging from 0.7087 to 0.7089, low εNd（t） values ranging from -16.9 to -17.8, 206Pb/204Pb = 17.15 to 17.17, 207Pb/204Pb = 15.45 to 15.47, and 208Pb/204Pb = 37.59 to 37.68. Results from the current study suggest that the mafic dykes are derived from partial melting of ancient lithospheric mantle that was variably hybridized by melts derived from foundered lower crustal eclogite. The mafic dykes may have been generated through subsequent insignificant crystal fractionation and very minor crustal contamination during magma ascent. Combined with previous studies, the current findings provide new evidence that the intense lithospheric thinning beneath the eastern Shandong Province of eastern China occurred at ~120 Ma, and that this condition was caused by the removal of the lower lithosphere （mantle and lower crust）.
基金the Key Research and Development Program of China(2016YFD0100302)the Central Public-interest Scientific Institution Basal Research Fund(Y2017PT39)the CAAS-Innovation Team Program(CAAS-XTCX2018020).
文摘Controlled pedigrees and the multi-decade timescale of national crop plant breeding programs offer a unique experimental context for examining how selection affects plant genomes.More than 3000 wheat cultivars have been registered,released,and documented since 1949 in China.In this study,a set of 145 elite cultivars selected from historical points of wheat breeding in China were re-sequenced.A total of 43.75 Tb of sequence data were generated with an average read depth of 17.94x for each cultivar,and more than 60.92 million SNPs and 2.54 million InDels were captured,based on the Chinese Spring RefSeq genome v1.0.Seventy years of breeder-driven selection led to dramatic changes in grain yield and related phenotypes,with distinct genomic regions and phenotypes tar-geted by different breeders across the decades.There are very clear instances illustrating how introduced Italian and otherforeign germplasm was integrated into Chinese wheat programs and reshaped the genomic landscape of local modern cultivars.Importantly,the resequencing data also highlighted significant asymmetric breeding selec-tion among the three sub-genomes:this was evident in both the collinear blocks for homeologous chromosomes and among sets of three homeologous genes.Accumulation of more newly assembled genes in newer cultivars implied the potential value of these genes in breeding.Conserved and extended sharing of linkage disequilibrium(LD)blocks was highlighted among pedigree-related cultivars,in which fewer haplotype differences were detected.Fixation or replacement of haplotypes from founder genotypes after generations of breeding was related to their breeding value.Based on the haplotype frequency changes in LD blocks of pedigree-related cultivars,we propose a strategy for evaluating the breeding value of any given line on the basis of the accumulation(pyramiding)of bene-ficial haplotypes.Collectively,our study demonstrates the influence of "founder genotypes" on the output of breeding efforts over many decades and also suggests that found
基金financially supported by the National Key Research and Development Program of China (2017YFD0500101)the Natural Science Foundation of Jiangsu Province (BK20170721)the China Association for Science and Technology Youth Talent Lift Project (2017-2019)
文摘Since late 2011,outbreaks of pseudorabies virus(PRV)have occurred in southern China causing major economic losses to the pig industry.We previously reported that variant PRV forms and recombination in China could be the source of continued epidemics.Here,we analyzed samples from intensive pig farms in eastern China between 2017 and 2019,and sequenced the main glycoproteins(gB,gC,gD,and gE)to study the evolution characteristics of PRV.Based on the gC gene,we found that PRV variants belong to clade 2 and detected a founder effect during by the PRV epidemic.In addition,we detected inter-and intra-clade recombination;in particular,inter-clade recombination in the gB genes of strains FJ-ZXF and FJ-W2,which were recombinant with clade 1 strains.We also found specific amino-acid changes and positively selected sites,possibly associated with functional changes.This analysis of the emergence of PRV in China illustrates the need for continuous monitoring and the development of vaccines against specific variants of PRV.
