Fig1A. Copyright: Reprinted with permission from Elsevier from [doi:10.1006/dbio.1998.9116] Dev Biol 205: 145-57, Lu MF; Cheng HT; Lacy AR; Kern MJ; Argao EA; Potter SS; Olson EN; Martin JF, Paired-related homeobox genes cooperate in handplate and hindlimb zeugopod morphogenesis. Copyright 1999