In Vitro Maturation of Cumulus-Oocyte Complexes and In Vitro Sperm Capacitation Significantly Increase the Expression and Enhance the Location of the CXCL12 and CXCR4 Anchoring Attractant Complex in Pigs

• Published in: Animals (Basel) Vol. 11; no. 1; p. 153
• Main Authors: Martinez, Cristina A, Alvarez-Rodriguez, Manuel, Casado-Bedmar, Maite, Rodriguez-Martinez, Heriberto
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-01-2021; MDPI
• Subjects: Anchoring; Animals; Attraction; Capacitation; Cell adhesion & migration; Chemokine receptors; Chemokines; Chemotactic factors; COCs; CXCL12 protein; CXCR4 protein; cytokine-receptor complexes; Cytokines; Cytoplasm; Experiments; Fertilization; Gametes; Gametocytes; Gene expression; Genital tract; Glycoproteins; Localization; Mammals; Motility; Oocytes; pig; Proteins; Reproductive technologies; Sperm; sperm chemoattractants; Spermatozoa; Swine; Sweden; Netherlands; United States > US; Spain; sperm chemoattractants; capacitation; COCs; fertilization; cytokine-receptor complexes; pig
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani11010153

Successful internal fertilization in mammals depends on several mechanisms, including those triggering the so-called "sperm attraction" towards the oocyte, which include some oocyte-derived sperm chemoattractants and interactive protein complexes, such as the cytokine C-X-C motif chemokine 12/C-X-C chemokine receptor type 4 (CXCL12-CXCR4) receptor complex. The presence and precise localization of these crucial proteins was determined hereby, for the first time, in porcine cumulus-oocyte complexes (COCs) and spermatozoa. CXCL12 was overexpressed in the cumulus cells of in vitro matured, compared to immature COCs (
< 0.05), with its receptor (CXCR4) being up-regulated in capacitated spermatozoa (
< 0.03) compared to uncapacitated spermatozoa. The CXCR4 appeared specifically localized in the sperm tail of non-capacitated spermatozoa and also in the sperm head of capacitated spermatozoa, suggesting that the CXCL12-CXCR4 signaling complex would play a pivotal role in attracting capacitated spermatozoa towards the oocyte, facilitating fertilization in pigs.