TFAP2A and TFAP2B redundantly regulate murine melanocyte development.

<p>(A-D) Lateral views of E12.0 control (A), <i>Tfap2a</i> SCM (B), <i>Tfap2b</i> SCM (C), or <i>Tfap2a/Tfap2b</i> DCM (D) mouse embryos processed for β-galactosidase (β-gal) staining. β-gal+ cells are a result of recombination of the <i>r26r</i>-allele by the <i>Wnt1-Cre</i> transgene, labeling neural crest cells and derivatives. (E-L) <i>In situ</i> hybridization expression patterns for <i>Pmel</i> (E-H, dorsal views) or <i>Dct</i> (I-L, lateral views) in control (E, I), <i>Tfap2a</i> SCM (F, J), <i>Tfap2b</i> SCM (G, K), or <i>Tfap2a/Tfap2b</i> DCM (H, L) E12.0 mouse embryos. Insets in (A-L) show higher magnification images just above the hindlimb in a similar viewing plane as the low magnification image. (M, N) Lateral views of the trunk processed for ɑ-neurofilament immunoreactivity in an E10.5 control (M) or <i>Tfap2a</i>/<i>Tfap2b</i> DCM (N), revealing developing dorsal root ganglia (a subset labeled with arrowheads). (O, P) Immunofluorescence of cryosections (cross-sectional plane at the level of the hindlimb) of an E12.0 control (O) or <i>Tfap2a</i>/<i>Tfap2b</i> DCM (P), containing a Tomato-reporter (<i>rTMr</i>) allele labeling neural crest cells and derivatives (arrowheads highlight a subset of melanocytes in the ventrolateral pathway). Abbreviations: DCM, double conditional mutant; drg, dorsal root ganglia; hl, hindlimb; nt, neural tube; SCM, single conditional mutant (A = <i>Tfap2a</i> or B = <i>Tfap2b</i>). Scale bars = 250μM, except M, N = 500μM.