Fig. 3. GPA-16 and GOA-1 become entirely dispensable for generation of pulling forces following GPB-1 depletion. Average peak velocities±s.e.m. of anterior (A) and posterior (P) spindle poles after spindle severing in one-cell stage embryos of the indicated genotypes. Actual values are given in Table S1 in the supplementary material. We found an analogous outcome when examining the movements of centrosomes during centration/rotation prior to mitosis: whereas centration/rotation is gradual, as in wild type, in embryos compromised for either goa-1 or gpa-16 function, it is abrupt and accompanied by back and forth movements in all genotypes in which gbp-1 function is compromised (see Movies 1-7 in the supplementary material). Values for wild type, goa-1(sa734) and gpb-1(RNAi) are from Afshar et al. (Afshar et al., 2004).