Genetic polymorphism of the growth hormone (GH5) gene in small ruminants

Document Type : Review Articles

Authors

Department of Cell Biology, National Research Centre, El Buhouth Street, 12311, Dokki, Egypt

Abstract

The present study was conducted to detect polymorphism of growth hormone (GH5) gene in different ovine and caprine breeds. A 468 bp fragment of growth hormone gene spanning over 5’UTR, exon1, intron1 and partial of exon 2 were amplified and digested with HaeIII endonuclease restriction enzyme to identify polymorphism at this locus and the results were confirmed by DNA sequence analysis. Screening polymorphisms within three caprine (n=52), and four ovine (n=67) breeds for GH5 gene was performed. For goats, Damascus and Zaraibi carried both the G and H alleles, but Barki breed displayed only the G allele. Both Damascus and Zaraibi goats carried both the G and H alleles with allele frequency of 0.80, 0.72 and 0.20, 0.28, respectively, and the GG genotype was the utmost prevailing in the examined breeds (70% in Damascus and 56% in Zaraibi). Nevertheless, Barki disclosed only the G allele. In sheep, all studied breeds appeared to carry only the H allele. Moreover, eight single nucleotide polymorphisms (SNPs) and one Indel were observed in Egyptian goat breeds and Damascus breeds in comparison to goat sequence accession No. D00476.1. While four single nucleotide polymorphisms (SNPs) were detected in different Egyptian sheep breeds in comparison to sheep sequence accession No M37310.1. These results may be employed to survey the interrelation of the detected SNPs with desirable traits in small ruminants.

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