Animals with recent shared ancestry frequently adapt in parallel to new but similar habitats, a process often underlined by repeated selection of the same genes. Yet, in contrast, few examples have demonstrated the significance of gene reuse in colonization of multiple disparate habitats. By analyzing 343 genomes of the widespread Asian honeybee, Apis cerana, we showed that multiple peripheral subspecies radiated from a central ancestral population and adapted independently to diverse habitats. We found strong evidence of gene reuse in the Leucokinin receptor (Lkr), which was repeatedly selected in almost all peripheral subspecies. Differential expression and RNA interference knockdown revealed the role of Lkr in influencing foraging labor division, suggesting that Lkr facilitates collective tendency for pollen/nectar collection as an adaptation to floral changes. Our results suggest that honeybees may accommodate diverse floral shifts during rapid radiation through fine-tuning individual foraging tendency, a seemingly complex process accomplished by gene reuse.

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The complete mitogenome of Cynoglossus roulei is 16,598 bp in length, containing 37 genes, among them, ND6 and eight tRNA genes are encoded by L-strand and other genes by H-strand, which are as same as those of typical mitogenome in fishes. The gene rearrangement related to one tRNA gene and CR were found, forming the gene order of CR-Gln-Ile-Met, which is the same as that of mitogenomes in all identified Cynoglossus speices. Phylogenetic tree based on 12 protein coding genes, tRNA and rRNA shows that C. roulei has a closer phylogenetic relationship to C. semilaevis.