Fig. 6: Expression profiles have coevolved extensively in bat limbs, including for genes involved in wing evolution.

a Transcriptome dataset reused from (Maier et al. 2017) with fore- and hindlimb samples at the ridge, bud and paddle stage for the bat Carollia perspicillata (stages CS13, CS14, CS15) and the mouse (E10, E10.5, E11.5). Coevolution of fore- and hind limb expression profiles was measured with nested models as in Fig. 4. Shh gene models are shown together with global quantifications. b Shh expression profiles from transcriptomes and published in situ hybridizations patterns, redrawn from ref.⁴³. Bat species is Miniopterus natalensis, mouse stages are E11.0, E11.5, E12.0. In both transcriptome and in situ hybridization, Shh expression is peaking in bat limbs as compared to mouse limbs. c Fgf8 expression profiles from transcriptomes and published in situ hybridizations patterns. Mouse patterns drawn from ref. ¹⁰¹ and¹⁰², and bat patterns from ref. ⁴⁴. In bats, a new domain of Fgf8 expression is observed in the mesenchyme from early stages, on top of the conserved expression of Fgf8 in the apical ectodermal ridge (AER) of both mouse and bats. In the latest stage, this mesenchymal expression is maintained in the wing only. d Gremlin1 expression profiles from transcriptomes and published in situ hybridizations patterns. Mouse patterns drawn from ref. ¹⁰¹ and bat patterns from ref.⁴⁴. Grem1, as Fgf8, co-evolves in early limb transcriptomic dataset. However, in later stages, published patterns show a wing-specific expression, while the bat leg has kept a similar expression profile as in mouse anterior limb.