TABLE 1.
Elements involved in early meiotic pairing in different species (Chr.) chromosome, (SC) synaptonemal complex, (PCs) pairing centers. *In Saccharomyces cerevisiae, there is a centromere coupling mechanism that involves the proximity of homologous and non-homologous centromeres.
| When does homologous pairing begin? | Does homologous pairing begin before DSBs formation? | Does homologous pairing occur in the absence of DSBs formation or recombination? | Do these elements promote homologous pairing? | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Centromere clustering | Telomere clustering | Chr. dynamics | SC | DNA sequences | RNA sequences | Cohesin meiotic components | ||||
| Saccharomyces cerevisiae | Prophase onset | No* | Yes | Yes | Yes | Yes | Yes | No data | No data | Yes |
| Schizosaccharomyces pombe | Prophase onset | Yes | Yes | Yes | Yes | Yes | No data | No data | Yes (non-coding RNA) | Yes |
| Drosophila melanogaster | Mitotic phase | Yes | Yes | Yes | No | Yes | Yes | Yes (rDNA, pairing sites) | No data | No data |
| Caenorhabditis elegans | Prophase onset | Yes | Yes | No (Holocentric chromosomes) | No | Yes | No | Yes (PCs) | No data | No data |
| Mus musculus | Before prophase | Yes | Yes | Yes | Yes | Yes | Yes | No data | No data | Yes |