Y-SNPs Scanning And Multi-copy Genes Identification In Water Buffalo

Water buffalo, as an important source of food for human, is the main draught animal inrice-growing areas of south China. According to the phenotype and habits, domestic buffalocan be divided into two types: swamp buffalo (2n=48) and river buffalo (2n=50). The Chinesenative buffalo belongs to swamp buffalo. At present, study on the origin and evolution ofbuffalo are involved in the technology of archaeology, morphology and molecular genetics.Extensive study of mtDNA can provide evidence of maternal origin, but research onmolecular genetic diversity of Y chromosome is needed to provide genetic evidence ofpaternal origin. In this dissertation, according to the published sequences information,50pairs of Y-spcific primers which are located in SRY、ZFY、USP9Y、DBY、UTY、OFD1Y、AMGY、AMELY、TSPY and RPS4Y1gene of MSY region were designed to screening thesingle nucleotide polymorphisms (Y-SNP) for229male samples from14Chinese nativebuffalo breeds as well as5river male samples as controls. In addition, this study also detectthe multi-copy genes of Y chromosome in swamp buffalo by TA cloning and DNA sequencingtechnology. The main results are as follows:1. Screening the Y-SNPs of domestic buffalo(1) By screening Y-SNPs for10genes (SRY、ZFY、USP9Y、DBY(DDX3Y）、UTY、OFD1Y、AMGY、AMELY、TSPY and RPS4Y1) of MSY region,9novel Y-SNPs distributed in theUSP9Y, ZFY and SRY gene,3Y-SNPs located among swamp buffalo breeds and6Y-SNPs located between swamp and river buffalo, which indicates rich Y chromosomegenetic diversity of domesticated buffalo.(2)6Y-SNPs between swamp and river buffalo all can be used as effective markers todifferentiate them.(3) We detected Y-SNP of river buffalo from Dehong buffalo, Jianghan buffalo and Guangxibuffalo, indicating massive historical introgression from river buffalo to native swampbuffalo.(4) Muli-copy genes are likely to cause double peak of individual sequencing results.2. Identification Y chromosome multi-cope gene in buffalo(1) For the first time, this study detected9genes (SRY、ZFY、USP9Y、DBY、TSPY、OFD1Y、AMGY、AMELY and RPS4Y1) of Y chromosome MSY region and poved preliminarily7multi-copy genes (USP9Y、SRY、 AMELY、DBY(DDX3Y)、OFD1Y、TSPY and RPS4Y1)in Chinese native buffalo by TA cloning and DNA sequencing technology, which can’t beused for screening Y-SNP. (2) SRY and USP9Y genes have been confirmed multi-copy gene, so they can’t be used tostudy Y chromosome genetic diversity of domesticated buffalo...