Fig. 2. The M lineage phenotypes of cc615 and tm252 mutants. All images are lateral views of animals with anterior to the left and dorsal up; asterisk indicates position of the vulva. The number of M-derived precursors or products in each panel indicates the total number of corresponding cell types in the particular mutant. (A-I) The M lineage of wild-type (A,D,G), cc615 (B,E,H) and tm252 (C,F,I) hermaphrodites as visualized by hlh-8::gfp. (A-C) Cleavage orientation of M showing the positions of the two M daughters. (D-F) The M lineage undifferentiated products at the late L1 stage. (D) 16 M-derived cells are present in wild-type animals, with eight visible in the focal plane shown. (E) A cc615 mutant animal with 12 M-derived cells, 11 of them are visible in the focal plane shown because of defects in cleavage orientations. (F) A tm252 mutant animal with 29 M-derived cells, 14 of them visible in the focal plane shown. (G-I) Positions of SMs at late L2 stage. (G) Two SMs (one out of focus) in wild-type animals at the future vulval region. (H,I) Multiple SMs (one focal plane shown) in cc615 (H) and tm252 (I) mutants, with some SMs exhibiting migration defects. (J-L) Differentiated M lineage products in adult wild-type (J), cc615 (K) and tm252 (L) hermaphrodites. Arrow, VM1 visualized by egl-15::gfp; open arrowhead and double-line arrow, embryonically-derived CCs and M-derived CCs, respectively, as visualized by intrinsic CC::gfp. (J) A wild-type animal with two dorsal M-derived CCs and four VM1s. (K) A cc615 animal with no M-derived CCs and extra VM1s (some do not migrate properly). (L) A tm252 animal with extra VM1s and CCs.