Progesterone from the cumulus cells is the sperm chemoattractant secreted by the rabbit oocyte cumulus complex

HÉCTOR ALEJANDRO GUIDOBALDI; MARÍA EUGENIA TEVES; DIEGO RAFAEL UÑATES; AGUSTÍN ANASTASÍA; LAURA CECILIA GIOJALAS

Plos One

Public Library of Science

Año: 2008 vol. 3 p. 3040 - 3049

1932-6203

 Sperm chemotaxis in mammals have been identified towards several female sources as follicular fluid (FF), oviduct fluid, and conditioned medium from the cumulus oophorus (CU) and the oocyte (O). Though several substances were confirmed as sperm chemoattractant, Progesterone (P) seems to be the best chemoattractant candidate, because: 1) spermatozoa express a cell surface P receptor, 2) capacitated spermatozoa are chemotactically attracted in vitro by gradients of low quantities of P; 3) the CU cells produce and secrete P after ovulation; 4) a gradient of P may be kept stable along the CU; and 5) the most probable site for sperm chemotaxis in vivo could be near and/or inside the CU. The aim of this study was to verify whether P is the sperm chemoattractant secreted by the rabbit oocyte-cumulus complex (OCC) in the rabbit, as a mammalian animal model. By means of videomicroscopy and computer image analysis we observed that only the CU are a