Differential gene expression in host races of Rhagoletis pomonella flies in diapause using RNAseq

Seasonal timing of reproduction is a key selective trait that drives ecological speciation in phytophagous insects. The apple maggot fly, Rhagoletis pomonella (Diptera: Tephritidae), is a classic example, with ancestral hawthorn-infesting host races eclosing later than a recently evolved host race that infests earlier-fruiting apples.  Thus, eclosion timing, determined by insect diapause, has large fitness consequences for the host races of the apple maggot fly, though it is currently unclear at what stage of diapause differentiation between host races is occurring.  We used an RNAseq approach to identify several hundred differentially expressed transcripts between host races as flies were removed from over-winter chilling.  We additionally measured gene expression 24-hr and 48-hr after removal from over-winter chilling and found expression increased greatly after 24 hours removed from chilling.