title: Human sperm chemotaxis: both the oocyte and its surrounding cumulus cells secrete sperm chemoattractants.
abstract: BACKGROUND
  Human sperm chemotaxis to pre-ovulatory follicular fluid is well established in vitro. However, it is not known whether the female's oocyte-cumulus complex secretes sperm chemoattractants subsequent to ovulation (for enabling sperm chemotaxis within the Fallopian tube) and, if so, which of these cell types--the oocyte or the cumulus oophorus--is the physiological origin of the secreted chemoattractant.
  
  
  METHODS
  By employing a directionality-based chemotaxis assay, we examined whether media conditioned with either individual, mature (metaphase II) human oocytes or the surrounding cumulus cells attract human sperm by chemotaxis.
  
  
  RESULTS
  We observed sperm chemotaxis to each of these media, suggesting that both the oocyte and the cumulus cells secrete sperm chemoattractants.
  
  
  CONCLUSIONS
  These observations suggest that sperm chemoattractants are secreted not only prior to ovulation within the follicle, as earlier studies have demonstrated, but also after oocyte maturation outside the follicle, and that there are two chemoattractant origins: the mature oocyte and the surrounding cumulus cells.
authors.affiliation: Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Fei
authors.initials: F
authors.lastname: Sun
authors.forename: Anat
authors.initials: A
authors.lastname: Bahat
authors.forename: Anna
authors.initials: A
authors.lastname: Gakamsky
authors.forename: Eliezer
authors.initials: E
authors.lastname: Girsh
authors.forename: Nathan
authors.initials: N
authors.lastname: Katz
authors.forename: Laura C
authors.initials: LC
authors.lastname: Giojalas
authors.forename: Ilan
authors.initials: I
authors.lastname: Tur-Kaspa
authors.forename: Michael
authors.initials: M
authors.lastname: Eisenbach
mesh_terms: D002478:Cells, Cultured; D002630:Chemotactic Factors / Q000378:metabolism*; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D017077:Culture Media, Conditioned / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008677:Metaphase; D009865:Oocytes / Q000378:metabolism*; D009866:Oogenesis / Q000502:physiology; D006080:Ovarian Follicle / Q000166:cytology / Q000378:metabolism*; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D002630:Chemotactic Factors; D017077:Culture Media, Conditioned