Genetic biodiversity studies on IGFBP-3 gene in Egyptian sheep breeds

Abstract

The insulin-like growth factor binding protein-3 (IGFBP-3) gene is a structural gene associated with the growth and development of the animals. The present investigation was carried out to study DNA polymorphism by PCR-RFLP of IGFBP-3 gene in four Egyptian local sheep breeds and its comparison with Indian sheep breeds. Genomic DNA was isolated from a total of 20 animals from four Egyptian breeds of sheep namely Rahmani, Ossimi, Awassi, and Barki. A fragment of IGFBP-3 gene, comprising of a part of exon 2, complete intron 2, exon 3, and a part of intron 3, was amplified. The amplified fragment was found to be 654 bp in sheep as compared to earlier reports of 651 bp in cattle and 655 bp in buffalo. On digestion of 654 bp with Hae III restriction enzyme yielded single restriction pattern of five fragments of sizes 201, 201, 87, 67, 57 in all the animals belonging to the four Egyptian breeds studied revealing absence of polymorphism in those four Egyptian sheep breeds. On comparison, this fragment was monomorphic in Indian sheep breeds and buffalo ,while it was reported to be polymorphic in cattle.