Format

Send to

Choose Destination
See comment in PubMed Commons below
Curr Biol. 2005 Jan 26;15(2):185-91.

A phylogenomic inventory of meiotic genes; evidence for sex in Giardia and an early eukaryotic origin of meiosis.

Author information

1
Department of Biology, Roanoke College, Salem, VA 24153, USA.

Abstract

Sexual reproduction in eukaryotes is accomplished by meiosis, a complex and specialized process of cell division that results in haploid cells (e.g., gametes). The stereotypical reductive division in meiosis is a major evolutionary innovation in eukaryotic cells, and delineating its history is key to understanding the evolution of sex. Meiosis arose early in eukaryotic evolution, but when and how meiosis arose and whether all eukaryotes have meiosis remain open questions. The known phylogenetic distribution of meiosis comprises plants, animals, fungi, and numerous protists. Diplomonads including Giardia intestinalis (syn. G. lamblia) are not known to have a sexual cycle; these protists may be an early-diverging lineage and could represent a premeiotic stage in eukaryotic evolution. We surveyed the ongoing G. intestinalis genome project data and have identified, verified, and analyzed a core set of putative meiotic genes-including five meiosis-specific genes-that are widely present among sexual eukaryotes. The presence of these genes indicates that: (1) Giardia is capable of meiosis and, thus, sexual reproduction, (2) the evolution of meiosis occurred early in eukaryotic evolution, and (3) the conserved meiotic machinery comprises a large set of genes that encode a variety of component proteins, including those involved in meiotic recombination.

PMID:
15668177
DOI:
10.1016/j.cub.2005.01.003
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center