A genetic test to identify carriers of the ovine Inverdale
fecundity gene
S.M. Galloway, L.M. Cambridge, H.M. Henry, T.C. Van Stijn and
G.H. Davis
AgResearch Molecular Biology Unit, Department of Biochemistry,
University of Otago, P.O. Box 56, Dunedin, New Zealand
Proceedings of the New Zealand Society of Animal Production. 1999, 59: 114-116
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.
Keywords: NZSAPAB;
Inverdale gene; FecXI ; X-chromosome; genetic test;
DNA markers; sheep (Ovis aries).
Last Updated 06-08-1999
