Analysis Of Population Genetic Structure And Select Signal In Chinese Indigenous Goat Breeds

There are many kinds of goat breeds in China,which have obvious characteristics,such as high reproductive capacity,resistance and coarse feeding.The protection and exploitation of goat genetic resources is an important foundation for the development of animal husbandry in China.However,the genetic diversity and characteristics of local goats are under certain threat with the rapid development of husbandry and the introduction of foreign goat breeds in recent years.Therefore,the study of the population structure,genetic diversity and gene selection marks,it can find out the genetic resources and provide theoretical supports for the protection and utilization of goats.In this study,we aimed to evaluate the population structure and genome trace among 240 individuals from 14 representative Chinese indigenous goat breeds and two wild goat populations by the goat 50 K SNP beadchip.Some suggestion was putted forward for the protection of goat genetic resources based on the study.The results are as follows:(1)The expected heterozygosity(He)and inbreeding coefficients(F)were used to estimate levels of genetic diversity.The results showed that the DYS,with certain degree of inbreeding,and low genetic diversity,had the highest F and the lowest He value,and XJS had the lowest F and the highest He value.We analyzed the population structure using principal component analysis(PCA),STRUCTURE,NETVIEW and constructed a Neighbor Joining(NJ)tree.The results demonstrated that the Chinese goats could be divided into 3 clusters: North population,Southwest population and South population.Wild goat and northern groups had closer relationship than other groups.The CDM had high inbreeding coefficient.(2)The genomic selection trace of Chinese goat breeds analyzed was investigated using XP-EHH and iHS methods.The results revealed that CSN3 was related to reproduction,ELK3,FGF5,PTPRT related to growth,while JAK2 was related to plateau adaptability.Some selected genes with function unknown need further study,such as PLGRKT,LOC106502473,LOC1021856,and XXYLT1.(3)In the end,we put forward some suggestions of goat protection in China on the basis of population genetic structure and gene selection marks.We first set a plan for the protection of goat genetic resources and conservation priorities.Second,a detail protecting plan for CDM and DYS was drafted.Subsequently,we need to deeply investigate genetic resource of Chinese goat breeds,and evaluate and monitor changes in genetic diversity.Last but not least,we should enhance the work in goat genetic diversity investigation,and combine utilization with conservation.