During meiotic prophase, chromosome telomeres aggregate at the nuclear envelope to form a `bouquet'. This clustering is thought somehow to facilitate pairing of homologous chromosomes and coincides with a polarization of nuclear and cytoplasmic components. The details of these two processes have remained obscure; however, studies by Zacheus Cande and co-workers using a novel method for culturing rye anthers that allows temporal analysis of meiotic events now provide significant insight into the clustering mechanism and its link with meiotic cell polarization. On p. 3747, the authors report that the microtubule-depolymerising drug colchicine inhibits telomere clustering but that other microtubule-depolymerising drugs have no effect. Their report on p. 3757 extends these studies to show that concentrations of colchicine that block telomere clustering do not inhibit the eccentric nuclear positioning and reorganization of nuclear pores that occur during meiotic cell polarization. This work indicates that, at least in rye, telomere clustering does not require cytoplasmic microtubules but depends on another, perhaps tubulin-related, colchicine target. Moreover, it demonstrates that reorganization of the meiotic cell and telomere clustering are not interdependent, suggesting they instead rely on a telomere-independent polarity cue.
- © The Company of Biologists Limited 2002