Fig. 2

Gross morphological defects in fbl null mutants are mainly seen in the head and eyes and are rescued by injection of fbl mRNA. (A) RT-qPCR quantification of relative levels of fbl mRNA at the indicated developmental stages shows the absence of fbl expression in mutants as early as the 24 hpf stage. Purple: wild-type, gray: siblings, pink: mutants. Statistical analyses were performed on four biological samples per condition. p-value (Kruskal-Wallis test) polysomes: 0.02. n.s., non-significant. (B1-B6) Lateral views of live embryos with anterior to the left and dorsal up. (B1-B2)fbl^hi2581Tg mutants start to display phenotypic abnormalities as early as the 24 hpf stage with necrosis in the midbrain area, slightly smaller eyes and a thin yolk extension. (B3-B4) At 48 hpf, mutant embryos have smaller eyes and smaller head than their siblings. In addition, mutant embryos display less pigmentation, pericardiac edema, a larger and rounder yolk and a thinner yolk extension. (B5-B6) At 48 hpf, fbl mutant embryos are largely rescued by fbl mRNA. In injected mutants, midbrain and yolk extension look similar in size to the ones in siblings. The size of the eye is bigger than in not injected mutants although remaining slightly smaller than in siblings. In panels B1-B9, eyes, midbrain area and yolk extension are respectively indicated by arrowheads, arrows and asterisks. Scale bar = 200 µm. (C) Classes of phenotypes of fbl mRNA injected embryos from an fbl^hi2581Tg incross. A strong decrease in the number of injected embryos with mutant phenotype is observed indicating that the fbl mRNA rescues the mutation.