Time-lapse imaging of MT organization in aust spermatocytes. Testes from wild-type and aust mutants expressing α-tubulin–GFP were dissected and spermatocytes undergoing meiosis I were imaged every 60 s. (A) Stills of metaphase/early anaphase spindles. aust cells show normal meiotic spindle morphology. (B) Selected frames from cells undergoing anaphase and telophase. In wild-type cells (see Video 1), a robust central spindle is formed early in anaphase and constricts as cells progress through telophase. In aust mutants (see Videos 2 and 3), spindles elongate during anaphase but no central spindle is formed. Bars, 10 μm.