Endodermal cell migration does not require Toddler signaling in cxcr4a mutants.
(A–B) Analysis of lateral mesodermal cell migration defects in cxcr4a mutant embryos by in situ hybridization for fn1a. Mesodermal cell migration is normal in stable cxcr4a single mutants. toddler;cxcr4a double mutants show mesodermal cell migration defects that resemble toddler single mutant siblings. (C) Representative images of embryos analyzed in D and E. In situ hybridization for sox17 at 75% epiboly; dorsal to the right. Cxcr4a morphants and cxcr4a mutants have excessive animal pole-directed migration of vegetal endoderm. Endoderm patterning in toddler;cxcr4a double mutants resembles wild-type embryos more than toddler single mutant siblings. (D) Measurement of frequency with which cells were found at a given location in an embryo of a certain genotype. A cell at the animal pole corresponds to 100% embryo height, while a cell at the vegetal pole corresponds to 0%. AP = Animal pole=100%; VP = vegetal pole=0%. (E) The number of lateral endodermal cells is unchanged between toddler single and toddler;cxcr4a double mutants. Each point represents a single embryo. Red bars are averages. (B and E) ns: p>0.46; *p<0.05; **p<0.0005; unpaired two-tailed t-test. N = number of independent experiments; n = number of embryos.