News

Sheep horn status gene pinpointed

Monday, 30 August 2010

An investigation into the locus of the polled/horn status gene in sheep led to the discovery the trait evolved during a single domestication event.

The principal author, AgResearch’s Natalie Pickering, said the findings exceeded the initial goal of the research. Markers in association with the causal gene are all that is required to enable selective breeding. However sequencing of key animals identified an insertion of messenger RNA in the gene, which was found to cause polledness.

“It’s not often a trait is so easy to pinpoint – most traits involve many parts of the genome working together.”

The gene was sequenced and validated in a group of animals and found to correlate. This also allowed the research team to identify its origin, and discover that the trait reflects a relatively recent selection sweep. The preference of polled animals around the time of domestication (about 7000 to 9000 years ago) is most likely the event which led to the selection of the gene.

The results have been used for a SNP-based haplotype test, which is currently available commercially though GenomNZ and Pfizer. It is most widely applied to Australian Merinos to allow selected breeding of desired traits while preventing the occurrence of the horn gene.

The research was funded by Ovita Ltd. and Beef and Lamb NZ.