Identification and characterization of SREBF2 expression and its association with chicken carcass traits.

The sterol regulatory element-binding transcription factor 2 gene (SREBF2) plays an important role in regulating lipid homeostasis. To reveal the genetic factors that underlie carcass fat deposition in chickens, we cloned the coding DNA sequence of chicken SREBF2, investigated SREBF2 mRNA expression levels in various tissues, detected single nucleotide polymorphisms (SNPs) in the exon regions of the gene, and conducted association analyses between single markers/haplotypes and carcass traits. The entire 2859-bp cDNA sequence of chicken SREBF2 that encoded 952 amino acids was obtained and characterized. SREBF2 mRNA was highly expressed in the uropygial gland, followed by the liver, breast muscle, and leg muscle. Ten SNPs were detected, and four (g.49363077T>A, g.49357503C>T, g.49355533G>A, and g.49354641G>A) were novel. When analyzing the associations between the single mutations and carcass traits, significant differences were found in three SNPs and g.49357915G>A was highly significantly associated with most carcass traits, except for abdominal fat weight and sebum thickness. In addition, haplotype combinations that were constructed using the SREBF2 SNPs were associated with breast muscle weight. Chickens with the combined genotype H21H21 had the highest live weight, carcass weight, eviscerated weight, and semi-eviscerated weight values. To the best of our knowledge, this is the first study conducted on chicken SREBF2 polymorphisms, which are predictive of the genetics that underlie the economic performance of chickens.