SRA

Background: Through the evolution of novel wing structures, bats (Order Chiroptera) became the only mammalian group to achieve powered flight. This achievement preceded the massive adaptive radiation of bats into diverse ecological niches. We investigate here some of the developmental processes that underlie the origin and subsequent diversification of one of the novel membranes of the bat wing: the plagiopatagium, which connects the fore- and hind limb in all bat species. Results: Our results suggest that the plagiopatagium initially arises through novel outgrowths from the body flank that subsequently merge to the limbs to generate the wing airfoil. Our findings further suggest that this merging process, which is highly conserved across bats, occurs through modulation of the programs controlling the development of the periderm of the epidermal epithelium. Finally, our results suggest that the shape of the plagiopatagium begins to diversify in bats only after this merging has occurred. Conclusions: This study demonstrates how a focus on the evolution of cellular processes can inform an understanding of the developmental factors shaping evolution of novel, highly adaptive structures. Overall design: Samples include RNAseq data for individuals for forelimb, heart, plagiopatagial, and uropatagial tissues from Erophylla sezekorni (3 samples for each tissue for Cretekos Stage 14 and 3 samples for each tissue for Cretekos Stage 16) and Pteronotus quadridens (3 samples for each tissue for Cretekos Stage 14 and 3 samples for each tissue for Cretekos Stage 16)