Background: Runs of homozygosity(ROHs) are homozygous segments of the genome where the two haplotypes inherited from the parents are identical. The current availability of genotypes for a very large number of single n...Background: Runs of homozygosity(ROHs) are homozygous segments of the genome where the two haplotypes inherited from the parents are identical. The current availability of genotypes for a very large number of single nucleotide polymorphisms(SNPs) is leading to more accurate characterization of ROHs in the whole genome. Here,we investigated the occurrence and distribution of ROHs in 3,692 Large White pigs and compared estimates of inbreeding coefficients calculated based on ROHs(FROH), homozygosity(FHOM), genomic relationship matrix(FGRM)and pedigree(FPED). Furthermore, we identified genomic regions with high ROH frequencies and annotated their candidate genes.Results: In total, 176,182 ROHs were identified from 3,569 animals, and all individuals displayed at least one ROH longer than 1 Mb. The ROHs identified were unevenly distributed on the autosomes. The highest and lowest coverages of Sus scrofa chromosomes(SSC) by ROH were on SSC14 and SSC13, respectively. The highest pairwise correlation among the different inbreeding coefficient estimates was 0.95 between FROH_totaland FHOM, while the lowest was-0.083 between FGRMand FPED. The correlations between FPEDand FROHusing four classes of ROH lengths ranged from 0.18 to 0.37 and increased with increasing ROH length, except for ROH > 10 Mb. Twelve ROH islands were located on four chromosomes(SSC1, 4, 6 and 14). These ROH islands harboured genes associated with reproduction, muscular development, fat deposition and adaptation, such as SIRT1, MYPN, SETDB1 and PSMD4.Conclusion: FROHcan be used to accurately assess individual inbreeding levels compared to other inbreeding coefficient estimators. In the absence of pedigree records, FROHcan provide an alternative to inbreeding estimates.Our findings can be used not only to effectively increase the response to selection by appropriately managing the rate of inbreeding and minimizing the negative effects of inbreeding depression but also to help detect genomic regions with an effect on traits under selection.展开更多
Runs of homozygosity (ROHs) are a class of important but poorly studied genomic variations and may be in- volved in individual susceptibility to diseases. To better understand ROH and its relationship with lung canc...Runs of homozygosity (ROHs) are a class of important but poorly studied genomic variations and may be in- volved in individual susceptibility to diseases. To better understand ROH and its relationship with lung cancer, we performed a genome-wide ROH analysis of a subset of a previous genome-wide case-control study (1,473 cases and 1,962 controls) in a Han Chinese population. ROHs were classified into two classes, based on lengths, intermedi- ate and long ROils, to evaluate their association with lung cancer risk using existing genome-wide single nucleofide polymorphism (SNP) data. We found that the overall level of intermediate ROHs was significantly associated with a decreased risk of lung cancer (odds ratio = 0.63; 95% confidence interval: 0.51-0.77; P = 4.78 × 10-6 ), while the long ROHs seemed to be a risk factor of lung cancer. We also identified one ROH region at 14q23A that was con- sistently associated with lung cancer risk in the study. These results indicated that ROHs may be a new class of variation which may be associated with lung cancer risk, and genetic variants at 14q23.1 may be involved in the development of lung cancer.展开更多
Erhualian(E),Meishan(MS)and Mi(MI)pigs are excellent indigenous pig breeds in Chinese Taihu Basin,which have made great contributions to the genetic improvement of commercial pigs.Investigation of the genetic structur...Erhualian(E),Meishan(MS)and Mi(MI)pigs are excellent indigenous pig breeds in Chinese Taihu Basin,which have made great contributions to the genetic improvement of commercial pigs.Investigation of the genetic structure and inbreeding level of the 3 pig breeds is of great significance for the sustainable breeding of commercial pigs.The length and number of runs of homozygosity(ROH)as well as the frequency of genomes covered by ROH can be used as indicators to evaluate the level of inbreeding and the origin of the population.In this study,the ROH characteristics of E,MS,MI and Landrace(L)pigs were analyzed by SLAF-seq data,and the inbreeding coefficient based on ROH(F_(ROH))was calculated.In addition,we have identified candidate genes in the genomic regions associated with ROH.A total of10568 ROH were detected in 116 individuals of 4 pig breeds.The analysis showed that there were significant differences in genetic structure between 3 Taihu Basin pig breeds and L,and the genetic structure of E and MI was similar.The results of F_(ROH)showed that the inbreeding level of MS was the highest(0.25±0.07),while E and MI were lower than L.Compared with the other 3 pig populations,MS showed a higher frequency of long ROH(>5 Mb),indicating higher inbreeding in MS in recent generations.A large number of candidate genes related to reproductive traits are located in the genomic regions with a high frequency of ROH,and these genes are expected to be used as candidate genes in marker-assisted selection(MAS)breeding programs.Our findings can provide theoretical support for genetic conservation and genetic improvement of 3 pig breeds in Chinese Taihu Basin.展开更多
Dear Sir,Iam Haiba Kaul,from the Department of Biochemistry,University of Health Sciences,Lahore,Pakistan.I write to present a study of oculocutaneous albinism(OCA)in consanguineous Pakistani families.OCA is a genet...Dear Sir,Iam Haiba Kaul,from the Department of Biochemistry,University of Health Sciences,Lahore,Pakistan.I write to present a study of oculocutaneous albinism(OCA)in consanguineous Pakistani families.OCA is a genetic defect of melanin biosynthesis that mainly affects eyes,skin and hair.展开更多
Dear Editor,I have carefully read the article entitled "Homozygosity mapping of a consanguineous Pakistani family affected with oculocutaneous albinism to Tyrosinase gene",published by Shakil et al in 2016 and found...Dear Editor,I have carefully read the article entitled "Homozygosity mapping of a consanguineous Pakistani family affected with oculocutaneous albinism to Tyrosinase gene",published by Shakil et al in 2016 and found it very interesting for the scientific community.展开更多
凡纳滨对虾的主要选育目标分为两个方面:一是培育具有较强抗病、抗逆性的“高抗系”(GK),二是培育具有快速生长特性的“快大系”(KD)。然而,国内缺少针对这两个选育群体的遗传多样性特别是基因组近交水平的调查分析研究。基于液相芯片...凡纳滨对虾的主要选育目标分为两个方面:一是培育具有较强抗病、抗逆性的“高抗系”(GK),二是培育具有快速生长特性的“快大系”(KD)。然而,国内缺少针对这两个选育群体的遗传多样性特别是基因组近交水平的调查分析研究。基于液相芯片“黄海芯1号”(55 K SNP)的基因分型数据,首次分析了GK(1064尾个体)和KD(564尾个体)选育群体的遗传结构和遗传多样性,调查了连续性纯合片段(ROH)的基因组分布特征,并重点评估了两个群体的基因组近交水平。PCA及进化树分析表明GK及KD群体可明确分层,亲缘关系热图表明KD群体内个体间的亲缘关系比GK群体更近。GK群体包括的家系数量更多,导致其遗传多样性高于KD群体;两群体间的F_(st)为0.09,存在中等遗传分化。GK和KD群体每个ROH的平均长度分别为(1.70±0.34)Mb和(1.65±0.38)Mb,每个样本ROH的平均数量分别为1.98±1.30和2.07±1.37。GK和KD群体0.8~1.25 Mb长度的ROH占比分别为11.41%和19.17%,表明KD群体的选育历史比GK群体更长。两个群体>2.25 Mb长度的ROH片段占比分别为10.26和9.74%,表明两个群体短期内未发生近亲交配。七种基因组近交系数评估结果表明,KD群体的近交水平高于GK群体。不依赖基础群体等位基因频率的F_(ROH)和F_(HOM)方法可准确地评价育种群体的真实近交水平,而F_(VR1)、F_(YA1)和F_(LH1)等依赖基础群体等位基因频率的方法可以用来比较群体及个体间的相对近交水平。上述结果为准确地评估育种群体的近交水平和优化育种方案提供了重要参考依据。展开更多
为了研究大型肉牛比利时蓝牛生长发育的遗传规律,筛选优异基因,试验基于Illumina Bovine SNP 50K芯片数据,采用PLINK软件对270头比利时蓝牛常染色体数据进行基因组长纯合片段(ROH)检测并基于选择信号分析,通过核苷酸多态性检测取前5%的...为了研究大型肉牛比利时蓝牛生长发育的遗传规律,筛选优异基因,试验基于Illumina Bovine SNP 50K芯片数据,采用PLINK软件对270头比利时蓝牛常染色体数据进行基因组长纯合片段(ROH)检测并基于选择信号分析,通过核苷酸多态性检测取前5%的单核苷酸多态性(single nucleotide polymorphism,SNP)位点,基于牛参考基因组(ARS-UCD1.2)对结果SNPs进行基因注释,对候选基因进行GO功能注释与KEGG信号通路富集分析,并计算染色体上ROH长度占基因组总长度的比例(FROH)。结果表明:在全部270个个体数据中共检测出1893个ROH片段,平均长度13.2311 Mb,平均FROH为0.0392;得到与生长发育相性状相关的基因有NEB、TET2、NEK11、NCKAP1、MYH15、EIF4A2、bta-miR-1248-1、DCAF8、PRORP、DOCK3、SYT15、MYEF2、ZDHHC13,与公牛生育能力相关的基因有CFAP61、DNAL1、BAG1。说明通过对比利时蓝牛生长发育性状相关分子标记的解析可以为比利时蓝牛遗传改良提供理论指导。展开更多
Global climate change has increased concerns regarding biodiversity loss.However,many key conservation issues still required further research,including demographic history,deleterious mutation load,adaptive evolution,...Global climate change has increased concerns regarding biodiversity loss.However,many key conservation issues still required further research,including demographic history,deleterious mutation load,adaptive evolution,and putative introgression.Here we generated the first chromosome-level genome of the endangered Chinese hazelnut,Corylus chinensis,and compared the genomic signatures with its sympatric widespread C.kwechowensis-C yunnanensis complex.We found large genome rearrangements across all Corylus species and identified species-specific expanded gene families that may be involved in adaptation.Population genomics revealed that both C.chinensis and the C.kwechowensis-C.yunnanensis complex had diverged into two genetic lineages,forming a consistent pattern of southwestern-northern differentiation.Population size of the narrow southwestern lineages of both species have decreased continuously since the late Miocene,whereas the widespread northern lineages have remained stable(C.chinensis) or have even recovered from population bottlenecks(C.kwechowensis-C.yunnanensis complex) during the Quaternary.Compared with C.kwechowensis-C. yunnanensis complex,C.chinensis showed significantly lower genomic diversity and higher inbreeding level.However,C.chinensis carried significantly fewer deleterious mutations than C.kwechowensis-C. yunnanensis complex,as more effective purging selection reduced the accumulation of homozygous variants.We also detected signals of positive selection and adaptive introgression in different lineages,which facilitated the accumulation of favorable variants and formation of local adaptation.Hence,both types of selection and exogenous introgression could have mitigated inbreeding and facilitated survival and persistence of C.chinensis.Overall,our study provides critical insights into lineage differentiation,local adaptation,and the potential for future recovery of endangered trees.展开更多
基金supported by the Natural Science Foundation of China (No.31572357) to FPZthe National Swine Industry Technology System(CARS-35) to LXW。
文摘Background: Runs of homozygosity(ROHs) are homozygous segments of the genome where the two haplotypes inherited from the parents are identical. The current availability of genotypes for a very large number of single nucleotide polymorphisms(SNPs) is leading to more accurate characterization of ROHs in the whole genome. Here,we investigated the occurrence and distribution of ROHs in 3,692 Large White pigs and compared estimates of inbreeding coefficients calculated based on ROHs(FROH), homozygosity(FHOM), genomic relationship matrix(FGRM)and pedigree(FPED). Furthermore, we identified genomic regions with high ROH frequencies and annotated their candidate genes.Results: In total, 176,182 ROHs were identified from 3,569 animals, and all individuals displayed at least one ROH longer than 1 Mb. The ROHs identified were unevenly distributed on the autosomes. The highest and lowest coverages of Sus scrofa chromosomes(SSC) by ROH were on SSC14 and SSC13, respectively. The highest pairwise correlation among the different inbreeding coefficient estimates was 0.95 between FROH_totaland FHOM, while the lowest was-0.083 between FGRMand FPED. The correlations between FPEDand FROHusing four classes of ROH lengths ranged from 0.18 to 0.37 and increased with increasing ROH length, except for ROH > 10 Mb. Twelve ROH islands were located on four chromosomes(SSC1, 4, 6 and 14). These ROH islands harboured genes associated with reproduction, muscular development, fat deposition and adaptation, such as SIRT1, MYPN, SETDB1 and PSMD4.Conclusion: FROHcan be used to accurately assess individual inbreeding levels compared to other inbreeding coefficient estimators. In the absence of pedigree records, FROHcan provide an alternative to inbreeding estimates.Our findings can be used not only to effectively increase the response to selection by appropriately managing the rate of inbreeding and minimizing the negative effects of inbreeding depression but also to help detect genomic regions with an effect on traits under selection.
基金supported in part the by National Natural Science Foundation of China(81230067,81270044 and 30901233)Doctoral Fund of Ministry of Education of China(20093234110001)+1 种基金New Century Excellent Talents in University(NCET-10-0178)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Runs of homozygosity (ROHs) are a class of important but poorly studied genomic variations and may be in- volved in individual susceptibility to diseases. To better understand ROH and its relationship with lung cancer, we performed a genome-wide ROH analysis of a subset of a previous genome-wide case-control study (1,473 cases and 1,962 controls) in a Han Chinese population. ROHs were classified into two classes, based on lengths, intermedi- ate and long ROils, to evaluate their association with lung cancer risk using existing genome-wide single nucleofide polymorphism (SNP) data. We found that the overall level of intermediate ROHs was significantly associated with a decreased risk of lung cancer (odds ratio = 0.63; 95% confidence interval: 0.51-0.77; P = 4.78 × 10-6 ), while the long ROHs seemed to be a risk factor of lung cancer. We also identified one ROH region at 14q23A that was con- sistently associated with lung cancer risk in the study. These results indicated that ROHs may be a new class of variation which may be associated with lung cancer risk, and genetic variants at 14q23.1 may be involved in the development of lung cancer.
基金supported by the Jiangsu Agricultural Science and Technology Innovation Found,China(SCX(20)3290)the Open Foundation of Key Laboratory of Urban Agriculture,Ministry of Agriculture and Rural Affairs of China(201906)the Joint Research Project on Pig Breeding in Anhui Province,China(340000211260001000431)。
文摘Erhualian(E),Meishan(MS)and Mi(MI)pigs are excellent indigenous pig breeds in Chinese Taihu Basin,which have made great contributions to the genetic improvement of commercial pigs.Investigation of the genetic structure and inbreeding level of the 3 pig breeds is of great significance for the sustainable breeding of commercial pigs.The length and number of runs of homozygosity(ROH)as well as the frequency of genomes covered by ROH can be used as indicators to evaluate the level of inbreeding and the origin of the population.In this study,the ROH characteristics of E,MS,MI and Landrace(L)pigs were analyzed by SLAF-seq data,and the inbreeding coefficient based on ROH(F_(ROH))was calculated.In addition,we have identified candidate genes in the genomic regions associated with ROH.A total of10568 ROH were detected in 116 individuals of 4 pig breeds.The analysis showed that there were significant differences in genetic structure between 3 Taihu Basin pig breeds and L,and the genetic structure of E and MI was similar.The results of F_(ROH)showed that the inbreeding level of MS was the highest(0.25±0.07),while E and MI were lower than L.Compared with the other 3 pig populations,MS showed a higher frequency of long ROH(>5 Mb),indicating higher inbreeding in MS in recent generations.A large number of candidate genes related to reproductive traits are located in the genomic regions with a high frequency of ROH,and these genes are expected to be used as candidate genes in marker-assisted selection(MAS)breeding programs.Our findings can provide theoretical support for genetic conservation and genetic improvement of 3 pig breeds in Chinese Taihu Basin.
基金Higher Education Commission (HEC) Islamabad, Pakistan for partly supporting this study
文摘Dear Sir,Iam Haiba Kaul,from the Department of Biochemistry,University of Health Sciences,Lahore,Pakistan.I write to present a study of oculocutaneous albinism(OCA)in consanguineous Pakistani families.OCA is a genetic defect of melanin biosynthesis that mainly affects eyes,skin and hair.
文摘Dear Editor,I have carefully read the article entitled "Homozygosity mapping of a consanguineous Pakistani family affected with oculocutaneous albinism to Tyrosinase gene",published by Shakil et al in 2016 and found it very interesting for the scientific community.
文摘凡纳滨对虾的主要选育目标分为两个方面:一是培育具有较强抗病、抗逆性的“高抗系”(GK),二是培育具有快速生长特性的“快大系”(KD)。然而,国内缺少针对这两个选育群体的遗传多样性特别是基因组近交水平的调查分析研究。基于液相芯片“黄海芯1号”(55 K SNP)的基因分型数据,首次分析了GK(1064尾个体)和KD(564尾个体)选育群体的遗传结构和遗传多样性,调查了连续性纯合片段(ROH)的基因组分布特征,并重点评估了两个群体的基因组近交水平。PCA及进化树分析表明GK及KD群体可明确分层,亲缘关系热图表明KD群体内个体间的亲缘关系比GK群体更近。GK群体包括的家系数量更多,导致其遗传多样性高于KD群体;两群体间的F_(st)为0.09,存在中等遗传分化。GK和KD群体每个ROH的平均长度分别为(1.70±0.34)Mb和(1.65±0.38)Mb,每个样本ROH的平均数量分别为1.98±1.30和2.07±1.37。GK和KD群体0.8~1.25 Mb长度的ROH占比分别为11.41%和19.17%,表明KD群体的选育历史比GK群体更长。两个群体>2.25 Mb长度的ROH片段占比分别为10.26和9.74%,表明两个群体短期内未发生近亲交配。七种基因组近交系数评估结果表明,KD群体的近交水平高于GK群体。不依赖基础群体等位基因频率的F_(ROH)和F_(HOM)方法可准确地评价育种群体的真实近交水平,而F_(VR1)、F_(YA1)和F_(LH1)等依赖基础群体等位基因频率的方法可以用来比较群体及个体间的相对近交水平。上述结果为准确地评估育种群体的近交水平和优化育种方案提供了重要参考依据。
基金supported by the National Natural Science Foundation of China(Grant No.32101541)the National Key R&D Program of China(Grant No.2022YFD2200400).
文摘Global climate change has increased concerns regarding biodiversity loss.However,many key conservation issues still required further research,including demographic history,deleterious mutation load,adaptive evolution,and putative introgression.Here we generated the first chromosome-level genome of the endangered Chinese hazelnut,Corylus chinensis,and compared the genomic signatures with its sympatric widespread C.kwechowensis-C yunnanensis complex.We found large genome rearrangements across all Corylus species and identified species-specific expanded gene families that may be involved in adaptation.Population genomics revealed that both C.chinensis and the C.kwechowensis-C.yunnanensis complex had diverged into two genetic lineages,forming a consistent pattern of southwestern-northern differentiation.Population size of the narrow southwestern lineages of both species have decreased continuously since the late Miocene,whereas the widespread northern lineages have remained stable(C.chinensis) or have even recovered from population bottlenecks(C.kwechowensis-C.yunnanensis complex) during the Quaternary.Compared with C.kwechowensis-C. yunnanensis complex,C.chinensis showed significantly lower genomic diversity and higher inbreeding level.However,C.chinensis carried significantly fewer deleterious mutations than C.kwechowensis-C. yunnanensis complex,as more effective purging selection reduced the accumulation of homozygous variants.We also detected signals of positive selection and adaptive introgression in different lineages,which facilitated the accumulation of favorable variants and formation of local adaptation.Hence,both types of selection and exogenous introgression could have mitigated inbreeding and facilitated survival and persistence of C.chinensis.Overall,our study provides critical insights into lineage differentiation,local adaptation,and the potential for future recovery of endangered trees.