Fig. 7

Leading region cells change their fate in the absence of Lef1 function. (A-C′) Tg(–8.0cldnb:lynGFP) zygotes were injected with a nuclear-localized Kaede mRNA and an average of two cells were photoconverted at 24 hpf. (A,B) Wild-type and lef1^nl2 mutant embryos immediately following photoconversion are shown. (C-D′) The embryos in A-B′ at 48 hpf showing the location of the progeny of the photoconverted cells. Note absence of the labeled (red) cells in the leading region of lef1^nl2 mutant embryos. (E) Quantification of converted cells at 24 hpf and their progeny at 48 hpf. (F) Localization of converted cells at 48 hpf in wild-type and lef1^nl2 mutants. Cells in lef1^nl2 mutants are significantly more likely to be localized in NMs and not in the primordia when compared with wild type (mean±s.e.m., n=27 wild-type and 16 lef1^nl2 mutant embryos, ^*P<0.04, Student′s t-test). (G-H′′) Still images from time-lapse movies (see Movies 3 and 4 in the supplementary material) demonstrating division of Kaede-positive cells (red) in a wild-type (G-G′′) and a lef1^nl2 embryos (H-H′′). Specific time points were chosen to show a subset of labeled cells just before and after cell divisions. Leading zone divisions marked by blue arrows, whereas cell divisions in rosettes are marked by yellow arrowheads. Scale bars: 20 μm.