Fig. 3. kal-1 mutants show embryonic lethality and L1 larvae morphological abnormalities. (A-D) DIC photomicrographs of embryos. (A) Control embryo at one and a half-fold stage; (B-D) mutant embryos in which ventral enclosure has failed; cells protrude ventrally outside of the embryonic mass (white arrows). These embryos will not hatch and they will eventually die. Confocal images of embryos stained with rhodaminated phalloidin (E,F) or AbMH27 (G,H). (E) Wild-type comma stage embryo showing the ordered pattern of cell boundaries. (F) This pattern is disrupted in a mutant, where cells establish ectopic contacts and are abnormally oriented (white arrow), clumping together and generating star-like shapes (white arrowhead). (G) In later wild-type embryos (threefold stage), each epithelial cell contacts only one anterior and one posterior partner. In mutant embryos of comparable stage (H), epithelial cells clump together (white arrow) and the normal pattern cannot be recognized. (I-L) DIC photomicrographs of L1 larvae. (I) Control L1 larva. (J-L) Mutant L1 larvae with abnormal body shape consisting in enlargements and bulges (white arrows), most often present in the head and tail regions. (M,N) Confocal images of larvae stained with AbMH27. In M, the line of lateral epithelial cells in a newly hatched larva is disorganized and the shape of the individual cells is altered. The white arrow points to a three partners boundary. In N, a group of epithelial cells has detached from the main lateral line and has organized a separate islet of epithelial cells. The outline of the animals (broken white lines) is drawn from parallel visible light micrographs (G, M and N).
