Bovine STAT5A gene polymorphism and its influence on growth traits in Podolica breed

Signal transducers and activators of transcription (STAT) are latent cytoplasmic transcription factors that mediate the actions of a variety of peptide hormones and cytokines within target cells. STAT5A is the main mediator of growth hormone action on target genes and plays a key role as intracellular mediator of prolactin signalling. In this study, the T→C nucleotide polymorphism at position 12743 in exon 16 of the bovine STAT5A gene was investigated with polymerase chain reaction-restriction fragment length polymorphism in a sample of Podolica young bulls. The Podolica breed derives from Bos primigenius podolicus (forebears of the modern Bos taurus), it has been present in Italy for a very long time and represents yet another example of successful biological adaptation to a hostile environment. The aims of this study were to estimate the allele and genotype frequencies in Podolica breed and to investigate a possible relationship between this polymorphism and some growth performance traits. The observed frequencies of C and T alleles were 0.344 and 0.656, respectively. The TT genotype was the most frequent in the studied population followed by TC and CC ones. Moreover, the animals carrying TT genotypes seem to show an initial faster growth, which determined higher bodyweight at 90 and 270 days of age; conversely, CC individuals exhibit a faster growth in the post-weaning period achieving the higher bodyweight at 450 days of age.