title: Forward Genetics Identifies a Requirement for the Izumo-like Immunoglobulin Superfamily spe-45 Gene in Caenorhabditis elegans Fertilization.
abstract: Fertilization is a conserved process in all sexually reproducing organisms whereby sperm bind and fuse with oocytes. Despite the importance of sperm-oocyte interactions in fertilization, the molecular underpinnings of this process are still not well understood. The only cognate ligand-receptor pair identified in the context of fertilization is sperm-surface Izumo and egg-surface Juno in the mouse [1]. Here we describe a genetic screening strategy to isolate fertilization mutants in Caenorhabditis elegans in order to generate a more complete inventory of molecules required for gamete interactions. From this screening strategy, we identified, cloned, and characterized spe-45, a gene that encodes an Izumo-like immunoglobulin superfamily protein. Mammalian Izumo is required for male fertility and has the same basic mutant phenotype as spe-45. Worms lacking spe-45 function produce morphologically normal and motile sperm that cannot fuse with oocytes despite direct contact in the reproductive tract. The power of this screen to identify proteins with ancient sperm functions suggests that characterization of additional mutants from our screen may reveal other deeply conserved components in fertility pathways and complement studies in other organisms.
authors.affiliation: Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA.
authors.forename: Gunasekaran
authors.initials: G
authors.lastname: Singaravelu
authors.affiliation: Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA.
authors.forename: Sina
authors.initials: S
authors.lastname: Rahimi
authors.affiliation: Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA.
authors.forename: Amber
authors.initials: A
authors.lastname: Krauchunas
authors.affiliation: Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA.
authors.forename: Anam
authors.initials: A
authors.lastname: Rizvi
authors.affiliation: Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA.
authors.forename: Sunny
authors.initials: S
authors.lastname: Dharia
authors.affiliation: College of William and Mary, PO Box 8795, Williamsburg, VA 23187, USA.
authors.forename: Diane
authors.initials: D
authors.lastname: Shakes
authors.affiliation: National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA.
authors.forename: Harold
authors.initials: H
authors.lastname: Smith
authors.affiliation: National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA.
authors.forename: Andy
authors.initials: A
authors.lastname: Golden
authors.affiliation: Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA. Electronic address: singson@waksman.rutgers.edu.
authors.forename: Andrew
authors.initials: A
authors.lastname: Singson
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D005260:Female; D005298:Fertility; D005306:Fertilization; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009865:Oocytes / Q000502:physiology; D013091:Spermatogenesis; D013094:Spermatozoa / Q000502:physiology
chemical_list: D029742:Caenorhabditis elegans Proteins; D008565:Membrane Proteins; C000611169:spe-45 protein, C elegans