Fertilization initiates the transition from anaphase I to metaphase II during female meiosis in C. elegans - PubMed (original) (raw)
Comparative Study
. 2005 Jun 1;282(1):218-30.
doi: 10.1016/j.ydbio.2005.03.009.
Affiliations
- PMID: 15936342
- DOI: 10.1016/j.ydbio.2005.03.009
Free article
Comparative Study
Fertilization initiates the transition from anaphase I to metaphase II during female meiosis in C. elegans
Karen L McNally et al. Dev Biol. 2005.
Free article
Abstract
Oocytes from most animals arrest twice during the meiotic cell cycle. The universally conserved prophase I arrest is released by a maturation hormone that allows progression to a second arrest point, typically metaphase I or II. This second arrest allows for short-term storage of fertilization-competent eggs and is released by signaling that occurs during fertilization. Nematodes are unique in that the maturation hormone is secreted by sperm rather than by the mother's somatic tissues. We have investigated the nature of the second arrest in matured but unfertilized Caenorhabditis elegans embryos using time-lapse imaging of GFP-tubulin or GFP-histone. Unfertilized embryos completed anaphase I but did not form polar bodies or assemble meiosis II spindles. Nevertheless, unfertilized embryos assembled female pronuclei at the same time as fertilized embryos. Analysis of embryos fertilized by sperm lacking the SPE-11 protein indicated that fertilization promotes meiotic cytokinesis through the SPE-11 protein but assembly of the meiosis II spindle is initiated through an SPE-11-independent pathway.