Study on a SNP at STAT4 gene in Italian Brown cows: possible association with milk yield

In mammals, signal transducers and activators of transcription (STAT s) are a family of latent cytoplasmic transcription factors that mediate the actions of a variety of peptide hormones and cytokines within target cells. STAT4 may play important roles in the activation of milk protein genes and the development of mammary g lands. To date, only few polymorphisms at STAT4 gene were found. The SNP considered in the present study is a transition (A>G) at position g.60330 (intron 4) of the STAT4 gene. Three different genotypes may be detected (AA, AG and GG) with PCR RFLP using M spI restriction enzyme. The Italian Brown cattle breed was originally a multipurpose breed reared in the Alps, subsequently it was selected as a dairy breed by importing Swiss Brown bulls from the U.S. It is one of the most reared milk purpose breed in Ita ly. Milk from Italian Brown cattle is particularly suitable for cheesemaking as it gives a higher cheese yield and it improves the manufacturing of dairy products by affecting also their biological and organoleptic qualities. The aims of the present study were to investigate the transition at position g.60330 (intron 4) of the STAT4 gene in a sample of Italian Brown cows and to find a possible relationship between this SNP and milk yield. In the investigated population, three possible genotypes were identif ied and the association with milk yield was investigated. However, further studies are needed to better clarify the role of this SNP on production traits in cattle.