Nuclear movement enforcing chromosome alignment in fission yeast - Meiosis without homolog synapsis

Abstract

Pairing of homologous chromosomes is a prerequisite for meiotic recombination. In most eukaryotic organisms, a synaptonemal complex is formed between homologous chromosomes along their entire lengths to stabilize pairing. Asynaptic organisms in which the canonical synaptonemal complex is not formed are still able to pair homologous chromosomes in a different way. In the fission yeast Schizosaccharomyces pombe, telomere clustering and oscillatory nuclear movement persist for the entire meiotic prophase. This characteristic chromosome arrangement promotes pairing of homologous chromosomes and may compensate for the lack of homolog synapsis. Here we review recent progress in elucidating the dynamics of homologous pairing, as well as the molecular mechanisms involved in the regulation of telomere clustering and nuclear movement in S. pombe. © 2007 Springer-Verlag Berlin Heidelberg.