Fig. 2. DMPP is toxic during the L2 stage by uncoupling cell divisions and
differentiation events from the molt cycle. (A) Toxicity period
assayed by transfer experiments of wild-type animals. Each dot represents the
surviving fraction of a synchronous population (n
25 worms)
transferred at a given time from standard to DMPP plates (black) or from DMPP
to standard plates (gray). (B,C) Exposure to DMPP delays L2
development. (B) L2 development was divided in five stages based on seam cell
(SC) divisions and anchor cell (AC) differentiation (1, undivided SC; 2, SC
divided once; 3, SC divided twice; 4, anterior SC fused to hyp7, no
Pcdh-3::GFP expressed in AC; 5, Pcdh-3::GFP expressed in
AC). (C) The proportion of worms belonging to these five stages was scored
every 2 hours during the L2 stage (n>20). Bars represent the mean
of two independent experiments (exp 1: 30, 32, 34, 36 hours; exp 2: 26, 28,
32, 34, 36 hours). (D) DMPP does not affect the timing of L1/L2 and
L2/L3 molts. Each dot represents the percentage of worms pumping at a given
time (n>25 individuals). (E) Schematic representation of
worm development at high DMPP concentration (0.75 mM). L2 development,
represented here by seam cell divisions, is delayed while the molt cycle is
not disrupted (hatched bars). Uncoupling these developmental events is lethal
at the L2/L3 molt.