PT  - JOURNAL ARTICLE
AU  - Michel F. Guiraldelli
AU  - Craig Eyster
AU  - Chih-Ying Lee
AU  - Dean Dawson
AU  - Roberto J. Pezza
TI  - Heterochromatin and the Synaptonemal Complex Maintain Homologous Centromere Interactions in Mouse Spermatocytes
AID  - 10.1101/264432
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 264432
4099  - http://biorxiv.org/content/early/2018/02/12/264432.short
4100  - http://biorxiv.org/content/early/2018/02/12/264432.full
AB  - How achiasmate chromosomes become aligned and segregate during meiotic prophase is an important issue in eukaryotic genetics. We show that chromosomes are frequently transmitted properly in the absence of a chiasma in mouse spermatocytes, suggesting the existence of back-up systems aiding achiasmate chromosome segregation. Here, we report mechanisms that maintain the alignment of homologous pairs prior to disjunction, which may enable achiasmate chromosomes to segregate from each other in meiosis I. We present direct physical evidence showing centromere interactions provide a stable physical link between chromosome pairs in the absence of recombination and that pericentromeric heterochromatin tethers the centromeres of chromosome pairs after dissolution of synaptonemal complex-mediated centromere paring. Our results establish for the first time in a mammal a role for heterochromatin in maintaining the alignment of chromosomes in the absence of euchromatic synapsis and suggest that homologous recognition may lead to segregation, even in the absence of recombination.HighlightsNon-recombination based systems promote achiasmate chromosome disjunction in mice.Two novel mechanisms maintain homologous pairs alignment just before segregation.One is directed by SYCP1 at centromeres; the other by centromeric heterochromatin.A comprehensive analysis of pre- and post-synaptic centromere interactions.