Mapping of the transcription start site (TSS) and identification of SNPs in the bovine neuropeptide Y (NPY) gene.

Neuropeptide Y is a key neurotransmitter of the central nervous system which plays a vital role in the feed energy homeostasis in mammals. Mutations in the regulatory and coding regions of the bovine NPY gene can potentially affect the neuronal regulation of appetite and feeding behaviour in cattle. The objectives of this experiment were to: a) fully characterize the bovine NPY gene transcript and b) identify the SNP diversity in both coding and non-coding regions of the NPY gene in a panel of Bos taurus and B. indicus cattle. Bovine NPY gene consists of four exons (99, 188, 81 and 195 nucleotides) and three introns. The promoter region of the NPY gene consists of TATA and GC boxes which are separated from the transcription start site (TSS) by 29 and ~100 nt, respectively. Analyses of the tissue specific expression of the bovine NPY gene revealed the presence of highly abundant NPY gene transcripts in the arcuate nucleus, cerebral and cerebellar regions of the bovine brain. We identified a total of 59 SNPs in the 8.4 kb region of the bovine NPY gene. Seven out of nine total SNPs in the promoter region affect binding of putative transcription factors. A high level of nucleotide diversity was evident in the promoter regions (2.84 x 10(-3)) compared to the exonic (1.44 x 10(-3)), intronic (1.30 x 10(-3)) and 3' untranslated (1.26 x 10(-3)) regions. The SNPs identified in different regions of bovine NPY gene may serve as a basis for understanding the regulation of the expression of the bovine NPY gene under a variety of physiological conditions and identification of genotypes with high feed energy conversion efficiency.