基于SNP芯片解析永胜红骨绵羊的群体遗传结构OA

[Objective]This study aims to explore the genetic background of Yongsheng Red-bone sheep and to reveal their genetic relationship and specificality with respect to sheep resources in Yunnan and surrounding areas and provides a scientific basis for the identification and conservation of local sheep genetic resources in Yunnan.[Method]A total of 24 Yongsheng Red-bone sheep were genotyped using the OvineSNP50 BeadChip.Six local Yunnan sheep breeds,Tibetan sheep,and Weining sheep were used for references.The population genetic structure of Yongsheng Red-bone sheep was systematically analyzed through phylogenetic tree construction,principal component analysis,ancestry analysis,runs of homozygosity(ROH)detection,and calculation of genetic differentiation index.[Result]Genotyping was performed using the Illumina Ovine SNP50 chip.A total of 46,129 high-quality SNPs were retained for subsequent analysis after quality control of 216 individuals in 9 sheep populations.The phylogenetic tree showed that Yongsheng Red-bone sheep formed a distinct branch independent of other sheep populations.The results of principal component analysis showed that Yongsheng Rred-bone sheep could be distinguished from Diqing sheep,Lanping Black-bone sheep,Ninglang sheep and Weining sheep,and the degree of differentiation was relatively high.ADMIXTURE analysis revealed that K=7 was the optimal number of ancestral populations for the nine sheep populations,and Yongsheng Red-bone sheep exhibited a unique ancestral composition,with some individuals showing admixture.ROH analysis indicated that the ROH lengths in this population were mainly concentrated in the range of 2～3 Mb,with an inbreeding coefficient(FROH)of 0.0953.The smallest genetic differentiation index(Fst)occurred between Yongsheng Red-boned sheep and Lanping Black-bone sheep(0.0459),while those with other populations were all greater than 0.06.[Conclusion]In summary,Yongsheng Red-bone sheep possess a unique population genetic structure and may have experienced historical gene flow with Lanping Black-bone sheep.