Figure 4.
Loss of the plastin PLST-1 ameliorates constriction of cyk-1(RNAi) rings. (A) Individual ring closure profiles of ABa/p cells. (B) Ring constriction rate (mean ±95% CI). n is the number of contractile rings analyzed (n = 27 in control, n = 26 in plst-1(prt89), n = 24 in cyk-1(RNAi), n = 40 in cyk-1(RNAi);plst-1(prt89), and n = 11 in cyk-1(RNAi);plst-1(RNAi)). Statistical significance was determined using unpaired one-way ANOVA followed by Bonferroni’s multiple comparison test. ****P < 0.0001; **P < 0.01; ns, not significant, P ≥ 0.05. (C) Images of constricting rings in ABa cells expressing NMY-2::GFP. Numbers on stills correspond to time in seconds. (D) Time projections of time-lapse imaging series, generated as illustrated in Fig. 1 F, for a time interval of 190 s, starting 100 s after both rings had a perimeter of ∼59 µm. The last frames correspond to a perimeter of 34 µm in the cyk-1(RNAi) ring and 13 µm in the cyk-1(RNAi);plst-1(prt89) ring. Consecutive images were acquired 10 s apart. (E) Instantaneous ring perimeter change (10 s interval) versus ring perimeter in ABa/p cells throughout constriction and zoom in on instantaneous ring perimeter changes above −0.5 µm for perimeters between 60 and 40 µm. 11 contractile rings were analyzed per condition. (F) Images of ABa rings with small discontinuities (arrows), which are observed around the ring circumference throughout ring constriction in cyk-1(RNAi);plst-1(prt89) rings. Scale bars in C, D, and F, 5 µm.