title: Human oocyte-derived sperm chemoattractant is a hydrophobic molecule associated with a carrier protein.
abstract: OBJECTIVE
  To characterize the nature of the human oocyte-derived chemoattractant.
  
  
  METHODS
  Laboratory in vitro study.
  
  
  METHODS
  Academic research institute.
  
  
  METHODS
  Ten healthy sperm donors. Oocyte-conditioned media from women undergoing IVF treatment because of male factor infertility.
  
  
  METHODS
  Sperm samples were processed by the migration-sedimentation technique. Oocyte-conditioned media were collected 2-3 hours after oocyte stripping.
  
  
  METHODS
  Sperm chemotaxis was assayed in a μ-slide chamber according to the direction of swimming relative to that of the chemical gradient.
  
  
  RESULTS
  Oocyte-conditioned media treated with proteases did not lose their chemotactic activity; on the contrary, they became more active, with the activity shifted to lower concentrations. When oocyte-conditioned media were subjected to hexane extraction, chemotactic activity was found in both the hydrophobic and aqueous phases. Known mammalian sperm chemoattractants were ruled out as oocyte-derived chemoattractants.
  
  
  CONCLUSIONS
  Our results suggest that the oocyte-derived chemoattractant is a hydrophobic nonpeptide molecule that, in an oocyte-conditioned medium, is associated with a carrier protein that enables its presence in a hydrophilic environment.
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
authors: Leah
authors: L
authors: Armon
authors: IVF and Infertility Unit, Assaf Harofeh Medical Center, Sackler School of Medicine, Tel-Aviv University, Zerifin, Israel.
authors: Ido
authors: I
authors: Ben-Ami
authors: IVF and Infertility Unit, Assaf Harofeh Medical Center, Sackler School of Medicine, Tel-Aviv University, Zerifin, Israel.
authors: Raphael
authors: R
authors: Ron-El
authors: Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel. Electronic address: m.eisenbach@weizmann.ac.il.
authors: Michael
authors: M
authors: Eisenbach
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D002630:Chemotactic Factors / Q000302:isolation & purification* / Q000378:metabolism* / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007248:Infertility, Male / Q000378:metabolism; D008297:Male; D009865:Oocytes / Q000378:metabolism*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D002630:Chemotactic Factors; D017077:Culture Media, Conditioned
keywords: Sperm chemotaxis; chemotaxis; oocyte-derived chemoattractant