Laboratory and wild Drosophila sechellia have conserved niche specialization phenotypes

Many studies investigating the proximate causes of evolutionary adaptations dissect potentially adaptive phenotypes under laboratory conditions where organisms are more easily experimentally manipulated. For such models, it remains unclear if organisms maintained long-term under laboratory conditions are representative of relatives in their natural environment. Drosophila sechellia, a fly endemic to the Seychelles that uses the toxic Morinda citrifolia noni fruit as a sole niche, has emerged as a powerful (neuro)genetic model for studying the molecular basis of ecological adaptations. Many studies have investigated the genetic and cellular basis of this species’ specialization in a laboratory setting using inbred strains that were collected many decades ago and have been maintained under conditions very different from those in nature. Here, we compare the phenotypes of these strains with recently collected wild D. sechellia to ask if long-term laboratory maintenance has led to a loss or degradation of phenotypes associated with their specialization. We show that newly derived D. sechellia lines display highly similar anatomical and behavioural phenotypes to long-term laboratory strains, including noni attraction and olfactory sensory neuron numbers, toxin resistance, egg size and circadian plasticity. These results support the use of inbred, genetically manipulatable, strains to study ecological adaptation.