Natural variation in food acquisition mediated via a Drosophila cGMP-dependent protein kinase

In natural environments where food abundance and quality can change drastically over time, animals must continuously alter their food acquisition strategies. Although genetic variation contributes to this plasticity, the specific genes involved and their interactions with the environment are poorly understood. Here we report that natural variation in the Drosophila gene, foraging (for), which encodes a cGMP-dependent protein kinase (PKG), affects larval food acquisition in an environmentally dependent fashion. When food is plentiful, the wild-type rover (for(R)) allele confers lower food intake and higher glucose absorption than both the wild-type sitter (for(s)) allele and the mutant for(s2) allele. When food is scarce, for(R), for(s) and for(s2) larvae increase food intake to a common maximal level, but for(R) larvae retain their increased absorption efficiency. Changes in for expression can induce corrective behavioral modifications in response to food deprivation. When reared in environments with low food levels, for(R) larvae have higher survivorship and faster development than for(s) and for(s2) larvae. Together, these results show that natural variation in for has far reaching implications affecting a suite of phenotypes involved in the regulation of food acquisition.