Genetic variation in Glp1r expression influences the rate of gastric emptying. Mus musculus

A C57BL6/J (B6) x CAST/Ei (CAST) strain intercross has revealed a new quantitative trait locus (QTL) on Chromosome (Chr) 17 controlling total food volume (Tfv1; LOD=7.6). Compared with B6, the CAST mice consume 39% more food volume per body weight in a macronutrient diet selection paradigm. Linkage analyses of total food volume revealed the presence of suggestive QTL on Chrs 2, 6, and 15 and a significant locus on Chr 17. An interval-specific congenic strain, B6.CAST-17, was then developed which verified the QTL. Microarray analysis of stomach in congenic and wildtype B6 mice revealed Glp1r as an expression candidate with physiological relevance to food intake. Further functional analysis of this gene revealed this gene as potential candidate for total food volume trait in mice Keywords: Comparative gene expression analysis Overall design: RNA obtained from six male B6.CAST-17 homozygous congenic mice and six male wild type B6 mice. Each strain was represented by two pools, each containing equal amounts of RNA from three animals, for a total of four samples. Thus, two biological replicates were analyzed for each strain.