Identification of the promoter region and genetic mutations of the porcine GALP gene

Galanin-like peptide (GALP) gene, encoding a member of the galanin family of neuropeptides involved in reproduction, was differentially expressed in PMSG-hCG stimulated pre-ovulatory ovarian follicles of Chinese Taihu and Large White sows in our previous study. In the present study, promoter region and genetic mutations of the porcine GALP gene were determined. A 1,322 bp contig in 5′-flanking region was predicted to contain 5 potential transcription promoters by Neural Network Promoter Prediction version 2.2. 5′-deletion expression in both CHO and hela cells showed that there were a negative regulatory element at −852 to −803 bp and a positive regulatory element at −1,318 to −1,269 bp. Comparative sequence analyses of Chinese Taihu and Large White GALP gene sequence revealed the c.*27C>G mutation in the 3′-UTR and the c.88–1225C>G mutation in intron 1, which can be detected by HhaI and AluI PCR–RFLP, respectively. The association analysis with litter size traits showed that at both loci CC and GG genotypes were different for NBA for all parities in DIV pigs (P < 0.05). However, two SNPs were not in significant linkage disequilibrium analyzed using SHEsis online software, and could be used in pig breeding individually.