Fat accumulation is a complex trait influenced by many environmental factors and genetic differences between individuals. Mouse polygenic models are best suited to study genetic factors. In our experiment, we used two lines selected for high (fat line) or low (lean line) body fat percentage. Previous studies have suggested that the gene Pla2g4e is one of the potential candidate genes that may explain part of the phenotypic difference between the lines. Therefore, as a first aim, we set out to analyse the expression of Pla2g4e in the hypothalamus between the lean and fat lines that were fed diets containing different levels of fat. We demonstrated a statistically significant increased gene expression in the hypothalamus of the obese mouse line, irrespective of the diet type or sex. The second objective was to characterise the gene Pla2g4e using bioinformatics methods with the objective of identifying polymorphisms between the lean and the obese lines that might be responsible for the differential expression. In the obese line, we found polymorphisms that may result in a loss of binding regions for miRNA and the transcriptional repressor CTCF, which we hypothesise may lead to increased expression of the gene Pla2g4e and consequently increased levels of body fat deposition in this line. These results demonstrate the importance of genetic background in obesity and provide a basis for the development of potential new biomarkers for fat deposition.
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