April 26, 2009

Genome of cattle breeds

The part I put in bold is interesting, as humans are themselves a "self-domesticated" species.

From the paper:
Our high resolution examination of cattle shows that unlike the dog—which has restricted diversity and high levels of inbreeding—domesticated cattle had a large ancestral population size and that more aurochs must have been domesticated than wolves; reducing the severity of the domestication bottleneck. SNP diversity within taurine breeds was similar to that of humans, but was significantly less than diversity within indicine breeds, which suggested that the Indian subcontinent was a major site of cattle domestication and predomestication diversity. Selection first for domestication and then for agricultural specialization have apparently reduced breed effective population sizes to relatively small numbers.
Related:

Science doi:10.1126/science.1167936

Genome-Wide Survey of SNP Variation Uncovers the Genetic Structure of Cattle Breeds

The Bovine HapMap Consortium

Abstract

The imprints of domestication and breed development on the genomes of livestock likely differ from those of companion animals. A deep draft sequence assembly of shotgun reads from a single Hereford female and comparative sequences sampled from six additional breeds were used to develop probes to interrogate 37,470 single-nucleotide polymorphisms (SNPs) in 497 cattle from 19 geographically and biologically diverse breeds. These data show that cattle have undergone a rapid recent decrease in effective population size from a very large ancestral population, possibly due to bottlenecks associated with domestication, selection, and breed formation. Domestication and artificial selection appear to have left detectable signatures of selection within the cattle genome, yet the current levels of diversity within breeds are at least as great as exists within humans.

Link

2 comments:

Maju said...

What does "indicine" mean? Indian?

terryt said...

"What does 'indicine' mean? Indian?"

Yes. There are basically two types of cattle Bos indicus and Bos taurus.

"which suggested that the Indian subcontinent was a major site of cattle domestication and predomestication diversity"

I read a book on cattle years ago and the claim was that cattle originated in India and spread from there long before modern humans had even left Africa.

"These data show that cattle have undergone a rapid recent decrease in effective population size".

Thanks to the Holstein/Friesian and, before then, the shorthorn, or Durham. Most modern breeds have large amounts of one or both in their ancestry. In fact the Holstein comes from a very limited gene pool to start with. Evidently most of the cattle in Holland perished in a big flood a couple of hundred years ago and the Dutch imported a few of the best cattle they were able to find. In fact the Dutch are big players in the NZ dairy industry today.