Genetic Deversity Of MtDNA Cytb Gene And Genetic Variation Of Whole-genome In Buffalo

Domestic buffalo is an important livestock,which can be divided into swamp buffalo and river buffalo according to the chromosome karyotype,phenotype and production performance.To illustrate the genetic diversity and genetic variability of buffaloes,1553 sequences of Cytb gene including 265 sequences from Laos,Thailand,India and Vietnam buffaloes,1288 Cytb sequences from GenBank were analyzed.In addition,the wholegenomes from two buffalo breeds(1 XG individual and 1 JH individual,respectively)were sequenced.The results were as follows:(1)The highest genetic diversity was detected in Laos buffalo and the lowest genetic diversity was detected in Thailand buffalo from Laos,Thailand,India,and Vietnam buffalo populations.(2)Two stop codons(AGA and AGG)were detected in all buffaloes.Interestingly,the AGG was only related with the lineage B of swamp buffalo,and supposed that the buffalo from lineage B maybe come from a wild buffalo.(3)15 SNPs of Cytb gene were detected,which can distinguish swamp buffalo from river buffalo.(4)Compared with the river buffalo,swamp buffalo,including 5 lineages(A,B,C,D,E),had more abundant genetic diversity,and the lineage A which maybe domesticated in the border of Southwest China and Southeast Asia experienced a strong population expansion.(5)In most chromosomes,the numbers of SNP and Indel from XG buffalo were bigger than that of JH buffalo.(6)The XG buffalo belong to swamp buffalo type,and the JH buffalo maybe a hybrid descendant from crossing of male river buffalo and female swamp buffalo.