Meiosis Online

Meiosis is an elaborately regulated cell division process that halves the number of chromosomes in reproductive cells from diploid to haploid. It is an essential and conservative stage in gamete formation in all sexually reproducing organisms (Figure below). Around meiosis studies, the key issues embrace meiosis initiation, synapsis & homologous recombination in both sexes, and meiosis arrest & resumption just for female, great efforts have been endeavored in these fields (1-4). Although meiosis is indispensable for sexual reproduction in both male and female, the meiotic division is sexually dimorphic: in male two successive segregation results in four round spermatids and in female, the first meiotic division gives birth to one secondary oocyte and a polar body after long time meiosis arrest, and then the secondary oocytes also maintain meiosis arrest until fertilization (1,3).
Figure 1

Currently, the Meiosis Online database has been updated on Jun 28, 2015, containing 2,007 manual curated functional proteins and 683 candidates predicted by GAS algorithm. The online service of Meiosis Online was implemented in PHP + MySQL + JavaScript. The database will be updated routinely as new meiosis genes/proteins are reported.


1. Handel, M.A. and Schimenti, J.C. (2010) Genetics of mammalian meiosis: regulation, dynamics and impact on fertility. Nature reviews. Genetics, 11:124-136.

2. Cooke, H.J. and Saunders, P.T. (2002) Mouse models of male infertility. Nature reviews. Genetics, 3:790-801.

3. Mehlmann, L.M. (2005) Stops and starts in mammalian oocytes: recent advances in understanding the regulation of meiotic arrest and oocyte maturation. Reproduction, 130:791-799.

4. Baudat, F., Y. Imai. (2013) Meiotic recombination in mammals: localization and regulation. Nature Reviews Genetics, 14(11):794-806.