Meiosis 2007 – Where have we got to and where are we going?

Bioinformatic identification of Ustilago maydis meiosis genes

“…In meiosis a diploid cell undergoes one round of DNA replication followed by two rounds of cell division, to produce haploid cells (Turner, 2007). Integral to meiosis is recombination.…”

Structural analysis of the human SYCE2–TEX12 complex provides molecular insights into synaptonemal complex assembly

“…Human fertility and genetic diversity depend on the successful execution of the genetic programme of meiosis. At the physical and functional centre of meiosis is the synaptonemal complex (SC), an enigmatic proteinaceous superstructure that holds together homologous chromosome pairs, providing the structural framework within which meiotic recombination and crossover formation occur [1][2][3][4][5]. The SC is essential for the successful completion of meiotic cell division: its disruption in mice leads to complete meiotic failure and resultant infertility [6][7][8][9][10], and its defective function in humans is associated with infertility and recurrent pregnancy loss (affecting 15% and 5% of couples, respectively), in addition to non-lethal aneuploidies such as Down's syndrome [1,6,11,12].…”

“…Assembly and disassembly of the SC are timely events within meiotic prophase I. SC assembly follows the induction of 200-400 double-strand breaks (DSBs) per cell that, through homology searching, establish local alignments between homologous chromosomes [3,6,17,18]. Short tracts of LEs begin to form along chromosome arms and are brought into 400 nm apposition at local alignments.…”

“…Its three-dimensional architecture further provides the necessary structural framework for completion of meiotic recombination, resulting in DSB resolution and crossover formation [11]. Once accomplished, the SC is disassembled, leaving crossovers as the sole physical links between homologous chromosomes during metaphase I [1][2][3].…”

Editorial 2008

“…We have again published two special issues, one on The Cytogenetics and Genomics of Crop Plants (Schubert & Houben 2007) and a second on Meiosis (Turner 2007). Our special issues aim to present up-to-date overviews of progress in fields of research that are currently reaching out in new directions.…”