Genome sequencing of the Sand rat, Psammomys obesus

The sand rat Psammomys obesus is a gerbil species native to deserts of North Africa and the MiddleEast. Sand rats survive with low caloric intake and when given high carbohydrate diets can becomeobese and develop symptoms of type II diabetes which, in extreme cases, leads to pancreatic failureand death. Previous studies have reported inability to detect the Pdx1 gene or protein in sand ratsand other gerbils, leading to the hypothesis that absence of this insulin-regulating transcription factormay underlie diabetes susceptibility. Here we have sequenced the sand rat genome andidentified of an unusual, extensive and mutationally-biased GC-rich genomic domain encompassing many functionally essential genes, including the elusive Pdx1.