Quick Dips

More Sheep

In what is being hailed as a significant discovery, AgResearch's molecular biology team has discovered a "marker" for a gene responsible for multiple births in sheep.

Such a marker is a signpost pointing out sheep that carry the gene in question. It also indicates the chromosome that carries the gene and the approximate site of the gene on that chromosome. Locating it is a prelude to locating the actual gene itself, which may then lead to better understanding, or even direct manipulation, of sheep fertility, which has obvious potential value for farmers. The gene is called the Booroola gene after a variety of sheep noted for high birth rates.

Aside from commercial considerations, however, the breakthrough is of wider scientific importance in several areas. Before now it was not established that direct DNA testing could be used to find gene markers. The many gene mapping projects around the world, such as the enormous Human Genome Project, now have a new tool to use.

Further, all mammals have some common genes and genetic order, and knowledge of a gene in one species helps understand the genetic makeup of other species. The Booroola gene may well turn out to have implications for the study of human fertility as well as that of sheep.

"New Zealand is already well recognised internationally for its expertise in sheep genetics, but this discovery has really put our genetic research on the scientific map," says Dr Grant Montgomery of the Molecular Biology Unit.