Coordinating nutrition and energy allocation in Drosophila melanogaster: Genetic mechanisms and evolution
Authors: Enoch Ng'oma; Joseph C. Gunn; Elizabeth Jones; Elizabeth G. King
Affiliation: University of Missouri, Columbia, MO
Keywords: Experimental evolution
Organisms have a basic necessity to acquire nutritional resources from the environment with which to build structures and maintain biological function. The quantity and quality of acquired nutrients, the ‘criteria’ for allocation to reproduction, maintenance, and storage to optimize the fitness-longevity trade-off is dictated by the quality of the environment and the organism’s condition. However, we do not fully understand the genetic mechanisms which coordinate allocation patterns in natural populations, and what the sources of genetic variation in allocation ‘decisions’ between populations in variable nutritional conditions are. We investigate these questions in an outbred population generated from intercrossing over 800 recombinant inbred lines from a multiparent population, itself derived from a global set of eight inbred founder lines. We imposed three diet selection regimes on this base population for 30 generations. In each generation, 12 large replicates (N > 2000 flies each) were treated with a fluctuating, a deteriorating, and a constant high nutrient regime. We sampled at generation 0, 5, 10, 20 and 30 and report single nucleotide polymorphism (SNP) frequencies associated with adaptation to selection patterns. We relate these results to changes in life history traits during adaptation including lifespan. We identify the loci associated with adaptation to dietary selection and shed light on the underlying genetic mechanisms. Our results have important implications to nutritional, gerontological, and climate change research.