Fig. 3. The early M lineage in wild-type and mls-2(cc615) animals. (A-D) The M lineage of wild type (A) and sample animals of cc615 mutants (B-D). The M lineage was followed from L1 to L4 stage in 15 wild-type and 32 cc615 mutant animals. Orientations of the first two divisions are indicated to show randomized cleavage orientations in cc615 mutants. All cc615 mutants exhibited reduced proliferation after the 8-M stage (B-D). We consistently observed loss of both M-derived CCs and supernumerary SM-like cells in cc615 mutants. Cells that may adopt the BWM fate or fail to express any M lineage markers are unmarked.