Distribution of phosphorylated myosin RLC (p-squash) in crane-fly spermatocytes. (A) Confocal fluorescence micrograph of p-squash in a control crane-fly spermatocyte at metaphase. P-squash localizes to the spindle, at the poles and, with lower intensities, in the chromosomes. (B) Confocal fluorescence micrograph of p-squash in a crane-fly spermatocyte treated with 50 nM CalA. P-squash concentrates around the chromosomes and at the poles. From the timing and appearance of the cell, this cell is in the stage after the half-bivalents moved backwards and reformed a pseudo-nucleus. (C) Fluorescence micrograph illustrating localisation of p-squash at the kinetochores of the two sex chromosomes, during autosomal anaphase, after CalA treatment. P-squash also localizes at the kinetochores of autosomes. (D) DIC image of the cell illustrated in (C) showing the two sex chromosomes and their kinetochores (asterisks). (E) Fluorescence micrograph illustrating localisation of p-squash in the midbody and in the daughter nuclei during cytokinesis. (F) Fluorescence micrograph illustrating increased staining with antibody against p-squash in the cleavage furrow and in the chromosomes after CalA treatment. Scale bar = 5 μm.