Chromatin Remodeling and Male Killing Figure 1. Formation of the gonomeric spindle in eggs obtained from KOS-10 Wolbachia-infected Drosophila bifasciata females. Eggs fixed 20 minutes AED were incubated with antibodies against b-tubulin (green), acetylated-a-tubulin (blue), and counterstained with Hoechst 33258 (red). (A) metaphase of the second meiosis: two anastral spindles, separated by a large microtubule aster, are aligned in tandem orthogonal to the egg surface. (B) Pronuclear apposition: male and female pronuclei come close within a large microtubule aster nucleated by two centrosomes derived by the male-basal body inherited centriole. (C) Metaphase of the first mitosis: the gonomeric spindle is formed by two closely apposed thin spindles sharing common poles; the parental complements move independently to the metaphase plate. (D) Anaphase of the first mitosis: parental complements start to migrate synchronously to the opposite poles. (E) Early telophase: midzone microtubules form the spindle midbody and daughter nuclei have reached the opposite poles. (F) Telophase of the second mitosis: two sister spindles hold four daughter nuclei. (G,H) Metaphase- PLoS ONE | www.plosone.org 3 January 2012 | Volume 7 | Issue 1 | e30045