Fig. 8

Expression patterns of aristaless (al), clawless (cll), and rotund (rn) in the walking legs of different panarthropod phyla relative to Distalless (Dll) expression. Ar—Arthropoda (Drosophila melanogaster), On—Onychophora (Euperipatoides kanangrensis), Ta—Tardigrada (Hypsibius exemplaris). bw—body wall. Stages when the illustrated expression patterns appeared are indicated. Lighter shades of al in D. melanogaster denotes positive expression, but the gene is not involved in patterning the specific leg region (Campbell & Tomlinson, 1998). The “?” in E. kanangrensis denotes the uncertainty of the extent of proximal expression of Dll relative to the other genes. Expression references: H. exemplaris (this study, Game & Smith, 2020); E. kanangrensis (Janssen et al. 2010, Oliveira et al. 2014); D. melanogaster (Campbell et al. 1993, Kojima et al. 2005, Natori et al. 2012, Jockusch & Smith 2015)