Fig. 1. C. elegans anillin-related proteins. (A) Schematics comparing features of the human and Drosophila anillins with the three C. elegans anillin homologs: C-terminal PH domains (grey); anillin homology (AH) regions (red); actin-binding and -bundling domains (blue); myosin-binding domains (green). For sequence comparisons, see Fig. S1B,C in the supplementary material. Worms were injected or soaked with dsRNA that targeted each of the anillin homologs. Embryos laid by the treated hermaphrodites between 48 and 72 hours after injection, or between 72 and 96 hours after the start of soaking, were counted (brood size, B) and the viability of the embryos (C) was measured. Data were normalized to the number and viability of embryos laid by worms treated with a control RNA against a yeast sequence not present in the C. elegans genome. Asterisks: significantly different from control (P<0.05, t-test; n=4-7 worms; 100 embryos/worm). (D) Extracts from worms injected with ani-1 dsRNA or soaked in ani-2 dsRNA were analyzed by western blotting. Numbers above control lanes indicate percentage of amount loaded in 100% lane. The same blots were probed for -tubulin as a loading control. (E) ANI-1 and ANI-2 are enriched in embryos and adult worms, respectively. Arrowheads indicate presumptive ANI-1 and ANI-2 bands. High-speed supernatants prepared from extracts of isolated embryos or whole worms were western blotted and probed with antibodies to ANI-1 and ANI-2. Blots were probed for -tubulin as a loading control. Identical results were obtained with crude extract (data not shown). (F) A C. elegans embryo undergoing cytokinesis was fixed and stained with Hoechst to label DNA and specific antibodies to myosin II (NMY-2), ANI-1 and ANI-2. Scale bar: 10 µm.