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.Fil: Sun, Fei. Weizmann Institute of Science. Department of Biological Chemistry; IsraelFil: Bahat, Anat. Weizmann Institute of Science. Department of Biological Chemistry; IsraelFil: Gakamsky, Anna. Weizmann Institute of Science. Department of Biological Chemistry; IsraelFil: Girsh, Eliezer. Ben Gurion University of the Negev; IsraelFil: Katz, Nathan. Ben Gurion University of the Negev; IsraelFil: Giojalas, Laura Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; ArgentinaFil: Tur-Kaspa, Ilan. Ben Gurion University of the Negev; IsraelFil: Eisenbach, Michael. Weizmann Institute of Science. Department of Biological Chemistry; Israe