Characterization of bovine MHC class II DRB3 diversity in South American Holstein cattle populations

Abstract

Holstein cattle dominate the global milk production industry because of their outstanding milk production, however, this breed is susceptible to tropical endemic pathogens and suffers from heat stress and thus fewer Holstein populations are raised in tropical areas. The bovine major histocompatibility complex (BoLA)-DRB3 class II gene is used as a marker for disease and immunological traits, and its polymorphism has been studied extensively in Holstein cattle from temperate and cold regions. We studied the genetic diversity of the BoLA-DRB3 gene in South American Holstein populations to determine whether tropical populations have diverged from those bred in temperate and cold regions by selection and/or crossbreeding with local native breeds. We specifically studied Exon 2 of this gene from 855 South American Holstein individuals by a polymerase chain reaction (PCR) sequence-based typing method. We found a high degree of gene diversity at the allelic (Na > 20 and He > 0.87) and molecular (π > 0.080) levels, but a low degree of population structure (FST = 0.009215). A principal components analysis and tree showed that the Bolivian subtropical population had the largest genetic divergence compared with Holsteins bred in temperate or cold regions, and that this population was closely related to Bolivian Creole cattle. Our results suggest that Holstein genetic divergence can be explained by selection and/or gene introgression from local germplasms. This is the first examination of BoLA-DRB3 in Holsteins adapted to tropical environments, and contributes to an ongoing effort to catalog bovine MHC allele frequencies by breed and location.

A novel association of BoLA DRB3 alleles in BLV infected cattle with different proviral loads

“…Even though several studies cited *1101 linked to PL susceptibility in different cattle breeds (XU et al, 1993;SULIMOVA et al, 1995;UDINA et al, 2003;PANEI et al, 2009;NIKBAKHT BRUJENI et al, 2016), it was associated with LPVL in Japanese cattle (MIYASAKA et al, 2013). In the present investigation we found a significant number of animals carrying this allele in our herd, compared to the population of Holstein in Argentina (TAKESHIMA et al, 2015); however, no association could be established between allele BoLA DRB3.2*1101 and BLV PVL. In the literature BoLA DRB3.2*0902 (or *11 determined by PCR-RFLP) allele was most strongly associated with PL resistance or LPVL profile in Holstein cattle (XU et al, 1993;ZANOTTI et al, 1996;MIRSKY et al, 1998;JULIARENA et al, 2008;PANEI et al, 2009;MIYASAKA et al, 2013).…”

“…In the literature BoLA DRB3.2*0902 (or *11 determined by PCR-RFLP) allele was most strongly associated with PL resistance or LPVL profile in Holstein cattle (XU et al, 1993;ZANOTTI et al, 1996;MIRSKY et al, 1998;JULIARENA et al, 2008;PANEI et al, 2009;MIYASAKA et al, 2013). In the present investigation we did not find this association, which could be due to a lower frequency of presentation of *0902 allele in this herd in comparison with the Argentinean Holstein populations (4.21% vs 6.4%, respectively) (TAKESHIMA et al, 2015).…”

“…In the present study, BoLA DRB3*1201 was the most significantly associated with HPVL (p = 0.0111), and this might be due to the fact that its frequency in the investigated population was about one third higher than in other Argentinean Holstein populations (11.21% vs 7.3%, respectively) (TAKESHIMA et al, 2015). In this investigation we also found a strong association between HPVL and the presence of BoLA DRB3*1501 (p = 0.0230).…”

“…There is not too much information about the allelic diversity of BoLA DRB3 class II gene in different cattle breeds. As far as it is known, only one study described this diversity in South American Holstein populations (TAKESHIMA et al, 2015). These authors found that BoLA DRB3*1501 appeared to be widely spread in the cattle of countries of South America: 18.2% in Bolivia, 17.7% in Paraguay, 21.4% in Peru, 21,7% in Chile, and 14.7% in Argentina.…”

Characterization of bovine MHC DRB3 diversity in global cattle breeds, with a focus on cattle in Myanmar

“…As a result of these studies there are 144 described BoLA-DRB3 alleles for bovines, and 303 subtypes listed in the Immuno Polymorphism Database (IPD-MHC) [30,31]. In addition, previous studies [16][17][18][19][20][21][22][23][24][25][26][27] have shown an even distribution of BoLA-DRB3 polymorphisms between the major bovine types (Bos taurus and B. indicus) and breeds. This is likely as a result of various factors including breed origin, arti cial or natural selection and geographical distribution.…”