Yak Genotyping Team at UW- Madison
University of Wisconsin Madison's (UWM) YAK Genotyping Team (Kathib, Porter and Urbano Braz) will conduct the largest study on the yak genome preformed to date, anywhere in the world. In addition to wild and domestic yak from the Qinghai Tibetan Plateau (QTP), we will include 1000 Foundation purebreds from the North American Yak Registry (NAYR). UWM will compare the genomes of NAYR yak with several different Bovid species and several subspecies of yak. This will allow us to identify genetic markers (SNPs) that are specific to NAYR yak.
The comparisons will include subspecies and breeds from the QTP, as well as hybrids from Tianzhu. Work will examine genetic conservation and divergence from wild-type yak, as well as introgression, inbreeding, and heterozygosity. This will tell us the type of yak to which the NAYR yak are most similar. This will also provide a valuable benchmark for North American yak breeders to understand their herds, both in the context of North American genetics, as well as the wider international yak community, and in comparison to original mutus/grunniens genomes. If preliminary data is replicated, this will demonstrate that NAYR yak are a domestic-wild subspecies cross, most closely resembling the wild-type yak (Bos mutus).
Additional analyses include a 3-species Bovid comparison including: cattle, yak, and bison. This will examine genetic conservation and divergence from cattle (Bos taurus and/or Bos indicus), as well as direct comparisons of introgression, inbreeding, and heterozygosity. This will tell us the type of bovid species to which the NAYR yak are most genetically similar, and how they differ. This will also provide a valuable benchmark for NAYR yak breeders to know how their herd compares to international standards for inbreeding and hybridization. The preliminary data suggests we most resemble buffalo (Bison bonasus and Bison bison). If this hypothesis is supported, it will indicate that historically yak are best understood as a sub-type of bison.
Of greatest importance to breeders, our third comparison will identify specific Single Nucleotide Polymorphisms (SNiPs), or genetic markers, which have been conserved between cattle and yak. The preliminary data suggests there are thousands of meaningful SNPs that correspond to those linked to specific traits in the well-researched and detailed catalog of the Bos taurus genome. In other words, it could lead to understanding the genetic architecture that informs phenotypic traits shared by both yak and cattle, including many known cattle markers for genetically heritable diseases, reproductive senescence, and a large body of performance traits. Moreover, the research is capable of verifying many identified breed- specific yak traits (eg. reproduction, sensory perception, energy metabolism, hypoxia response, immunity, aggression, size, etc.). I have compiled a substantial list of SNPs to be replicated from previous research, with some new markers to be identified. This will lead to specific genetic markers that breeders can use to inform breeding choices - enhancing positive traits and decreasing deleterious ones.
It’s exciting work and acknowledgements will go to IYAK for their large contributions to the data. Our team should have some preliminary data to discuss in a couple of months.
Nicole Porter, PhD