Figure 1. Expression and function of
lin-32 in hypodermal cells:(A) The
lin-32 null mutants showed various morphologies of head hypodermis. Localization of the hypodermis on left lateral view (orange-colored area). The wild-type animal had a smooth head shape in a differential interference contrast (DIC) image. The
lin-32 null mutants exhibited abnormal head shape. The nose tip was curved (white lines) and a cavity was observed (arrowhead). (DIC images). Scale bars = 100 µm. (B, C) The
lin-32 gene is necessary for head morphogenesis. (B) All wild-type animals (100%) presented standard heads (n = 6), but 81.2% of the
lin-32 null mutants exhibited a change in head morphology ("Aberrant," n = 11). **p = 0.0090 < 0.01 (Fisher's exact test). (C) Rescue experiment. Head morphological changes in
lin-32 null mutants (0% normal, n = 20) were rescued by LIN-32 expression from its own promoter (80.0% normal, n = 25). ***p < 0.0001 (Fisher's exact test). (D) Schematic diagram of hypodermal cell localization (
hyp3,
hyp4,
hyp6, and
hyp7) on the dorsal anterior side of the head primordium of a 1.5-fold stage embryo (Sulston et al. 1983). DIC image of a 1.5-fold stage embryo. Fluorescence image of EGFP expressed by the
lin-32 promoter. EGFP expression was observed in dorsal hypodermal cells centered around
hyp6. Scale bar (white bracket) = 10 µm.