European Journal of Zoological Research
Abstract
Author(s): Abbas Hajihosseinlo, Ali Hashemi, SeyedAlireza Razavi-Sheshdeh and Nasrollah Pirany
The insulin-like growth factor 1 (IGF-I) gene has been described in several studies as a candidate gene for
growth.Thispreliminary study attempts to identify associations between growth traits and genetic polymorphisms at
the 5�¢���� flanking region IGF-I in Makui sheep. DNA samples from100Makuisheep,anindigenous Iranian
breed,wereevaluated in the research. Polymerase chain reaction-single strand conformation polymorphism (PCRSSCP)
analysis of the 5�¢���� flanking region (Exon1) of the ovine revealed that the IGF-I gene had the following three
banding patterns (genotypes); A/A, A/G and G/G. The evaluation of an association between these SSCP patterns
with birth weight (BW), weaning weight (WW),six month weight(SW),nine month weight (9W), average daily gain
from birth to weaning (GBW), weaning to six months (GWS), from six months to nine months (GSN), from nine
months to yearling weight(GNY) and developmenttraits in oneyear demonstrated a positive effect of the pattern
(Genotype) A/G with GBW and weaning weight (WW)andsix month weight(SW). The pattern (Genotype)
A/Ademonstrated superior birth weight when compared to those with other gene patterns.GBW, GNY and biometric
or developmenttraits were influenced significantly by sex (p<0.01)exceptRL: rump length trait.Also type of birth
effect influenced early weight changes but had no significant effect on GSN, GNY traits(p>0.05).These results
demonstrated that IGF-I gene could be a genetic locus, or linked to a major gene that significantly affects growth
and the afore-mentioned economic traits in sheep.
