Distribution of major histocompatibility complex DRB3 allelic frequencies in the 11

TAKESHIMA S-N; MATSUMOTO Y.; ARAINGA M.; KIM J.; MIYASAKA T.; XUE G.; DE LA BARRA V.G.; GIOVAMBATTISTA G.; ONUMA M.; AIDA Y.

Tokio

Simposio; 9th International Symposium of Veterinary Immunology; 2010

The major histocompatibility complex (MHC) genes are particularly interesting to animal breeders and veterinary genetists because they are associated with genetic resistance and susceptibility to a wide array of diseases such as bovine mastitis and bovine leukaemia. Despite of the information of allele frequency of breed were very important for detecting the disease associated allele, these data were still not sufficient to know the distribution of BoLA-DRB3 allele. Recently we developed PCR-sequence based typing (SBT) method for assignment of BoLA-DRB3 allele, and this method make possible to determine DRB3 allele frequencies of various breeds. In this study, we tried to investigate BoLA-DRB3 allele of various cattle breeds in South American, we genotyped 2343 head of cattle containing 369 Japanese, 385 Argentina, 139 Paraguayan, 328 Peruvian, 499 Bolivian and 623 Chilean using new PCR-SBT. Collected breeds were Wagyu, Japanese Shorthorn, Jersey, Holstein, Gir, Zebu, Nelore, Ovelo Colorado, Ovelo Negro, Black and Red Angus, and mixed. 72 alleles out of known 118 alleles and three unknown new alleles are detected. All three new alleles were detected from Bolivian mix-breed and one of three was also detected from Peruvian and Paraguayan Holstein. Number of detected alleles in each breeds were from 14 (Japanese Jersey) to 35 (Peruvian Zebu and Bolivian Mix breed) and Expected Heterozygosity were from 0.858 (Peruvian Zebu) to 0.952 (Bolivian Mix breed). To overview of allele frequencies, we constructed phylogenetic tree which clearly showed that intrinsic allele frequencies were neither depending on countries nor on farm but instead on breed. Especially, Holstein has intrinsic allele frequencies in all farms except one in Argentine. Meanwhile, some Ovelo Colorado breed were very near to Holstein but from some other farm it is most far from Holstein within the Bos Taurus breed. Moreover, Japanese Wagyu and Chilean Wagyu are resembled but Chilean Wagyu also had the characteristic of Angus. These frequency data provide infrastructure for understating the host factor of disease susceptibility.