%0 Journal Article
%T Gamete interactions require transmembranous immunoglobulin-like proteins with conserved roles during evolution
%A Hitoshi Nishimura
%A Steven W. L'Hernault
%J Archive of "Worm".
%D 2016
%R 10.1080/21624054.2016.1197485
%X C. elegans spe-9 class genes are male germline-enriched in their expression and indispensable during sperm-oocyte fusion. Identification of mammalian orthologs that exhibit similar functions to these C. elegans genes has been a challenge. The mouse Izumo1 gene encodes a sperm-specific, immunoglobulin (Ig)-like transmembrane (TM) protein that is required for gamete fusion. We recently identified the C. elegans spe-45 gene, which shows male germline-enriched expression and encodes an Ig-like TM protein. spe-45 mutant worms produced otherwise normal spermatozoa that cannot fuse with oocytes, causing essentially the same phenotype as that seen in the Izumo1-knockout mice. By counting the number of self-sperm in the spermatheca of spe-45 hermaphrodites, it was found that this gene might be involved in sperm guidance from the uterus into the spermatheca, as well as gamete fusion. Moreover, we discovered that SPE-45 and IZUMO1 share certain functions for gamete fusion, which are presumably related to binding with cis- and/or trans-partners. Intriguingly, various organisms have Ig-like TM proteins that act during gamete interactions, indicating the wide-spread utility of Ig-like domains during fertilization
%K C. elegans
%K evolution
%K fertilization
%K immunoglobulin-like domain
%K IZUMO1
%K male germline
%K mouse
%K SPE-45
%K SPE-9 class protein
%K sperm
%K transmembrane protein
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5022667/