Use of Growth Hormone Gene Polymorphism in Selecting Osmanabadi and Sangamneri Goats

Goat meat holds tremendous demand irrespective of cultural and religious barriers. Therefore selection of goats for improved growth is advantageous. Growth hormone (GH) is a polypeptide hormone which is the major regulator of growth of animals, encoded by growth hormone gene. Polymorphic GH gene confers more active variants of the hormone enhancing growth. The objectives of the present study were to identify single nucleotide polymorphisms (SNPs) of GH gene and their association with growth traits of goats. DNA samples of 240 goats from two Indian breeds, namely Osmanabadi and Sangamneri were subjected to single strand confirmation polymorphism (SSCP) followed by DNA sequencing techniques with the objectives of studing single nucleotide polymorphisms (SNPs) in GH gene and their association with growth traits.

Twenty three and eighteen nucleotide changes were observed in Osmanabadi and Sangamneri goats, respectively in comparison to goat sequence of accession No. 00476. Of them, twelve were seen unique to both goat breeds indicating considerable deviation from exotic goat sequence. The study revealed point mutations of G200T, A815G, A1753, C1763T and A1789G in GH gene sequence of both goat breeds. In contrast, A497G, A499G C500G C501-2 C730T C781T and C2055T were observed specific to Osmanabadi and Sangamneri breeds respectively indicating the possibility of using them as breed specific markers. G200T resulted GG, GT and TT genotypes and of them, GT was associated with heavy body weight and GG with low body weight (P≤0.05) in both the breeds. Sangamneri GT genotypes were 6.5% taller (P≤0.05) than GG. Similarly, AG of A815G revealed low body weight. AA of A1753 insertion revealed heavy body weight in both the breeds and 7% longer body in Sangamneri breed. Heterozygote counterparts for C1763T and A1780G SNPs exhibited heavy body weights ((P≤0.05). It was concluded that SNPs and their association with body weight may be useful in selecting goats for higher growth traits.

DOI: http://dx.doi.org/10.4038/tar.v21i4.3316

TAR 2010; 21(3): 398-411