Abstract

The Inverdale high fecundity gene (FecXI ) is carried on the sheep X-chromosome. This provides a convenient means of producing prolific single copy carrier ewes because all daughters of a carrier ram will inherit the gene. A single copy of the gene increases litter size by about 0.6 lambs per ewe lambing. However, ewes homozygous for the gene are infertile. Production of elite rams that carry the gene requires the ability to distinguish between non-carrier and single copy carrier animals. Three DNA markers flanking the gene in a 10 cM (centiMorgan) region have been used to develop a genetic test that can identify single and double copy carriers in most cases. The test relies on detecting inheritance of the Inverdale region of the X-chromosome in offspring of known carriers. Validity of the genetic test has been confirmed by progeny testing of rams and laparoscopy of ewes. The test has recently been adapted to DNA obtained from a few plucked wool follicles.

SM, Galloway, LM Cambridge, HM Henry, TC Van Stijn, and GH Davis

Proceedings of the New Zealand Society of Animal Production, Volume 59, , 114-116, 1999