Fig. 12. Cryptic ErbB requirements during metamorphosis revealed by sensitized genetic backgrounds. (A) kit mutants (reared with DMSO) develop fewer metamorphic melanophores than wild type. (B) kit mutants reared during metamorphosis with AG1478 have an additional metamorphic melanophore deficiency. (C) csf1r mutants have similar numbers of melanophores to wild type through the middle metamorphic stage shown (Parichy et al., 2000b). (D) csfr1r mutants reared in AG1478 during metamorphosis exhibit a sharp reduction in melanophore numbers, as well as increased larval mortality (not shown). (E) Melanophore densities (±1 s.e.) are moderately or significantly reduced in sensitized backgrounds when treated with AG1478 (AG) or PD158780 (PD) compared with DMSO-only controls (con). Shared letters above bars indicate treatments that are not significantly different from one another (P>0.05) within each genetic background. Treatment sample sizes are shown at the base of each bar. Scale bar: in A, 300 µm for A,B; in C, 300 µm for C,D.