Prediction And Related-gene Identification Of Heterosis In Cattle Based On High Density Chip

To explore the heterosis of Simmental,Wagyu cattle and Holstein,excavate its candidate genes associated with heterosis and analyze the genetic mechanisms of heterosis in cattle,we used SNP chips to predict heterosis in Simmental,Wagyu cattle and Holstein and analyze the combining ability of the cross between German Simmental cattle and Holstein.At the same time,the genome-wide selection signal detection was carried out on the German Simmental cattle,Holstein cattle and the F1 of their hybrids by F_ST method and the genome-wide association analysis was conducted for birth weight and coat color traits of the F1.the results are as follows:1.Heterosis was predicted by using genome-wide and trait-related SNP markers to estimate the genetic distance between three parental lines of Simmental beef cattle,Wagyu cattle and Holstein,The results showed that Holstein and Simmental beef cattle were the better hybrid combinations in growth and development traits.Through the analysis of the combining ability of the cross between German Simmental cattle and Holstein,it was found that the hybrids of this combination showed good heterosis for birth weight trait.According to the results of combining ability between 30 families,the German Simmental cattle which labels were 29617,426989,12FFM13,FW13213107 and Holstein can be selected first in actual production to obtain higher birth weight.2.The genome-wide selection signal detection was carried out on the German Simmental cattle,Holstein cattle and the F1 of their hybrids by F_ST method and the selected SNPs were mapped and annotated It was found that 38 genes related to growth and development,milk production,carcass,reproduction and meat quality traits of cattle,such as KCNIP4,PRKN,THADA,POMC,OXTR,ABCG1and MYO5B,were positively selected in F1.3.Based on the genome-wide association analysis for the birth weight and coat color traits of the F1between German Simmental and Holstein cattle,three SNPs which significantly affected the heterosis were screened for birth weight traits,which were distributed on chromosomes 2 and 11,and Bovine HD1100000027 on chromosome 11 was mapped to ZC3H6 gene.For coat color traits,12 SNPs that significantly affected heterosis were screened,all of which were distributed on chromosome 5,and 5candidate genes RNF41、ZC3H10、ERBB3、PMEL and OR10A7 were located,among which PMEL and ERBB3 genes were reported as candidate genes related to bovine coat color.