Molecular cloning and characterization of the porcine FTO promoter and coding regions

The fat mass and obesity associated gene (FTO) has been widely reported to be associated with fat mass or fat deposition in different species. In the present study, we cloned both promoter and coding regions of the gene in pigs with over 5 Kb of sequence for the former region and 1,596 bp for the latter region. Comparative analysis of the promoter region among 20 species including pig revealed four conserved regions that harbor transcriptional factors involved in adipose differentiation. Using a pooled DNA sequencing approach, we discovered 39 single nucleotide polymorphisms (SNPs) in the pig FTO gene and four of them were genotyped on 716 pigs representing 3 European and 18 Chinese indigenous pig breeds plus samples of wild boars. We found that TCGG is a favored haplotype in Chinese wild boars and 16 indigenous pig breeds, while Li Cha Black and Tong Cheng pigs had the specific dominant haplotypes of TTGG and TCGA, respectively. ATGA was the main haplotype found in Large White and Duroc pigs, but the haplotype of ATGG was the major type in Landrace. Taken together, these data provide a valuable foundation for the community to fully study the function of FTO gene in pigs.