Growth hormone gene and their association with body weights and morphometric characters in Nellore sheep

Abstract

The aim of the study was to identify growth hormone gene polymorphisms and their association with body weights and morphometric characters in Nellore sheep. A total of 50 Nellore sheep (12 months old) maintained at Instructional Livestock Farm Complex, Mamnoor were genotyped at 5' regulatory region and exon 4 by using polymerase chain reaction-single stranded chain polymorphism (PCR-SSCP) technique. The PCR-SSCP of 5' regulatory region (210 bp) yielded three genotypes AA, AB and BB corresponding to two allelic variants A and B. The genotypic frequencies were 0.24, 0.42 and 0.34 for AA, AB and BB, respectively and the allelic frequencies of A and B were 0.45 and 0.55, respectively. The exon-4 (191 bp) yielded two genotypes, AA (0.60) and AB (0.40) corresponding to two allelic variants A and B. The allelic frequencies of A and B were 0.80 and 0.20, respectively. No significant associations were found between different SSCP genotypes and body weights and morphometric characters. The study showed that two loci were polymorphic and hence further studies are required to find out association of polymorphism, if any, with different economic traits in Nellore sheep.