Relationship Between Polymorphism of IGF-1 Gene in Dams with Body Weight and Dimension in Birth and Weaning in Turkish Awassi Sheep

Abstract

The insulin-like growth factor 1 (IGF-I) gene has been described in several studies as a candidate gene for
growth traits in farm animals. The objective of this study was to Identify the polymorphism in the 5’
flanking region of the Turkish Awassi sheep insulin-like growth factor I (IGF-I) gene and relationship of
this genotype with some growth traits. The DNA of 64 ewes was evaluated. Primers were supplied for
amplifying the specific segment. Polymerase Chain Reaction (PCR) accomplished after finding the best
condition to do the reaction. The specific segment amplified well. RFLP markers were used for detecting
the polymorphisms of the segment. its analysis was performed by incubating of PCR product by HaeII
restriction enzyme at 37°C for 1 h. Gels were visualized using 3.5% agarose. The distribution percentage
of polymorphism of the 5’ flanking region IGF-1 gene in ewe's sample were 49.09, 41.82 and 9.09 % for
AA, AB & BB genotype respectively. The variations among these percentages were highly significant
(P≤0.01). The effect of this polymorphism was significant (P≤0.05) on lamb's birth weight, body length
heart girth at birth, while it lacked significance on the remaining traits with various IGF-1
polymorphism. At lambs weaning, significant variance of weaning weight, weight gain from birth to
weaning and body mass index were noticed with various IGF-1 polymorphism). In conclusion, gene
expression of IGF-1 gene revealed possibility of adopted this gene in sheep improvement strategy to
increase the economic gain in the breeding schemes.