Human sperm chemotaxis: both the oocyte and its surrounding cumulus cells secrete sperm chemoattractants.
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.
Sun
Fei
F
Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel.
Bahat
Anat
A
Gakamsky
Anna
A
Girsh
Eliezer
E
Katz
Nathan
N
Giojalas
Laura C
LC
Tur-Kaspa
Ilan
I
Eisenbach
Michael
M
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*
D002630:Chemotactic Factors; D017077:Culture Media, Conditioned