title: Tetraspanin-interacting protein IGSF8 is dispensable for mouse fertility.
abstract: OBJECTIVE
  To determine the physiological role of IGSF8 for fertility.
  
  
  METHODS
  Experimental prospective study.
  
  
  METHODS
  Academic basic research laboratory.
  
  
  METHODS
  C57BL/6J and hybrid B6D2F1 mice, as well as Cd9 and Igsf8 knockout mice (C57BL/6J and 129/SvJ mix background), were used for this study.
  
  
  METHODS
  None.
  
  
  METHODS
  In vitro and in vivo fertility tests of Igsf8 knockout mice.
  
  
  RESULTS
  Tetraspanin family member CD9 plays an important role in sperm-egg fusion. Recently, some researchers have reported that CD9 tightly associates with the immunoglobulin superfamily member IGSF8 on the egg surface and that IGSF8 is undetectable on the surface of Cd9-deficient eggs. This led us to hypothesize that IGSF8 participates in sperm-egg fusion together with CD9. To examine the physiological role of IGSF8 in vivo, we generated Igsf8-deficient mice by homologous recombination and examined the fertility of the females.
  
  
  CONCLUSIONS
  The Igsf8-deficient female mice showed no fertilization defect in vitro or in vivo. We observed that Igsf8-deficient eggs retained the normal level and localization of CD9, resulting in normal microvilli formation, which indicates that IGSF8 is dispensable in fertility.
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Suita City, Osaka, Japan. ninoue@biken.osaka-u.ac.jp
authors.forename: Naokazu
authors.initials: N
authors.lastname: Inoue
authors.forename: Takao
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Masahito
authors.initials: M
authors.lastname: Ikawa
authors.forename: Masaru
authors.initials: M
authors.lastname: Okabe
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism* / Q000502:physiology; D005260:Female; D005298:Fertility / Q000502:physiology*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000172:deficiency* / Q000378:metabolism* / Q000502:physiology; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011247:Pregnancy; D011446:Prospective Studies; D060245:Tetraspanin 29 / Q000172:deficiency / Q000378:metabolism / Q000502:physiology; D059470:Tetraspanins / Q000378:metabolism* / Q000502:physiology
chemical_list: D002352:Carrier Proteins; C554870:Cd9 protein, mouse; C539703:IgSF8 protein, mouse; D008565:Membrane Proteins; D060245:Tetraspanin 29; D059470:Tetraspanins