Leah Armon1, Ido Ben-Ami2, Raphael Ron-El2, Michael Eisenbach3. 1. Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel. 2. IVF and Infertility Unit, Assaf Harofeh Medical Center, Sackler School of Medicine, Tel-Aviv University, Zerifin, Israel. 3. Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel. Electronic address: m.eisenbach@weizmann.ac.il.
Abstract
OBJECTIVE: To characterize the nature of the human oocyte-derived chemoattractant. DESIGN: Laboratory in vitro study. SETTING: Academic research institute. PATIENT(S): Ten healthy sperm donors. Oocyte-conditioned media from women undergoing IVF treatment because of male factor infertility. INTERVENTION(S): Sperm samples were processed by the migration-sedimentation technique. Oocyte-conditioned media were collected 2-3 hours after oocyte stripping. MAIN OUTCOME MEASURE(S): Sperm chemotaxis was assayed in a μ-slide chamber according to the direction of swimming relative to that of the chemical gradient. RESULT(S): 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. CONCLUSION(S): 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.
OBJECTIVE: To characterize the nature of the human oocyte-derived chemoattractant. DESIGN: Laboratory in vitro study. SETTING: Academic research institute. PATIENT(S): Ten healthy sperm donors. Oocyte-conditioned media from women undergoing IVF treatment because of male factor infertility. INTERVENTION(S): Sperm samples were processed by the migration-sedimentation technique. Oocyte-conditioned media were collected 2-3 hours after oocyte stripping. MAIN OUTCOME MEASURE(S): Sperm chemotaxis was assayed in a μ-slide chamber according to the direction of swimming relative to that of the chemical gradient. RESULT(S): 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. CONCLUSION(S): 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: Sean G Brown; Stephen J Publicover; Christopher L R Barratt; Sarah J Martins da Silva Journal: Hum Reprod Update Date: 2019-11-05 Impact factor: 15.610