Expression Studies of the Obesity Candidate Gene<i>FTO</i>in Pig

Abstract

Obesity is an increasing problem worldwide and research on candidate genes in good animal models is highly needed. The pig is an excellent model as its metabolism, organ size, and eating habits resemble that of humans. The present study is focused on the characterization of the fat mass and obesity associated gene (FTO) in pig. This gene has recently been associated with increased body mass index in several human populations. To establish information on the expression profile of FTO in the pig we performed quantitative PCR in a panel of adult pig tissues and in tissues sampled at different developmental stages. Expression of the FTO transcript was detected in all tissues tested with significantly higher levels in brain tissues (cortex, cerebellum, and hippocampus; P < 0.001). These levels varied through the development and between the specific parts of the brain studied (i.e., frontal cortex and cerebellum). Additionally, in order to see the involvement of the FTO gene in obesity, the changes in expression level were investigated in a nutritional study in brain of Gottingen minipigs under a high cholesterol diet. Significantly higher (P < 0.01) levels of FTO transcript were found in cortex when compared with cerebellum of the high-cholesterol fed pigs. Furthermore, SNPs were investigated in the coding sequence of the FTO in the Gottingen minipig and in the Danish commercial pig. Eleven synonymous SNPs and a two bp insertion were found between the two pig lines.