Lack of genetic association of markers near the leptin gene with
carcass fat content in Coopworth sheep lines selected for and against
fatness
A.W. CAMPBELL, T.E. BROAD, N.B. JOPSON, H.R. BURKIN, K.G. DODDS,
B.A. VEENVLIET, W.E. BAIN, G.J. GREER AND J.C. McEWAN
AgResearch, Invermay Agricultural Centre, Private Bag 50034,
Mosgiel, New Zealand
NZSAP 2003 Abstract No. 43
Proceedings of the New Zealand Society of Animal Production
63: 176-178
Leptin is an important hormone in controlling food intake and
energy expenditure in mammalian species. The present study evaluated
levels of serum leptin in Coopworth sheep selected for and against
subcutaneous fat depth for 10 generations. Significant differences in
serum leptin concentrations were found between fat and lean sheep
(P<0.05) and between male and female sheep (P<0.01). Serum leptin
concentration was positively correlated with carcass fatness and there
was a clear relationship between mean progeny serum leptin
concentrations and the breeding value for fat. Serum leptin
concentrations were greater (P<0.05) in lambs selected from the fat
line (2.69ng/ml) than in lambs selected from the lean line (2.18ng/ml).
A microsatellite marker, OarCP26, already mapped on sheep chromosome 4
(OAR4) was located in a sheep yeast artificial chromosome (YAC) clone
that was positive for the leptin gene (LEP). This confirmed the
independent assignment of LEP, mapped using a sheep cell hybrid
panel, to OAR4. No significant differences in the allele frequencies of
OarCP26 and two other flanking markers (TGLA116 and OarHH335) were
detected in the lean and fat selection lines suggesting genes other than
leptin are causing the differences in fat between the lean and fat
Coopworth lines.
Keywords: NZSAPAB;
leptin; sheep; carcass fat content
Last Updated 8/07/2004
