title: Supplementation with cumulus cell masses improves the in vitro meiotic competence of porcine cumulus-oocytes complexes derived from small follicles.
abstract: The present study was conducted to examine the supplemented effect of cumulus cell masses (CCMs) derived from middle follicle (MF; 3-6 mm diameter) on the morphology and the meiotic or developmental competence of oocytes from small follicles (SF; 1-2 mm diameter). The number of cumulus cells surrounding oocytes just after collection was also lower in cumulus-oocyte complexes (COCs) from SF than MF. The ooplasmic diameter of oocytes was significantly smaller in SF-derived oocytes than MF-derived ones before and after in vitro maturation (IVM), whereas the diameter significantly increased during the culture. Co-culture of SF-derived COCs with MF-derived CCMs during IVM significantly improved the meiotic competence of the oocytes to the metaphase-II stage. Furthermore, the ooplasmic diameter of SF-derived COCs during IVM was increased to the similar size of MF-derived those in the presence of MF-derived CCMs. The abilities of oocytes to be penetrated, to form male pronuclear formation and to cleave or develop to the blastocyst stage were not affected by the co-culture with CCMs. Electrophoretic analysis of CCM secretions clearly showed the presence of more protein(s) approximately 27.6 kDa in the conditioned medium when supplemented with MF-derived CCMs. In conclusion, we demonstrate that supplementation with MF-derived CCMs improves the ooplasmic diameter and meiotic competence of SF-derived oocytes.
authors.affiliation: Department of Animal Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Matsunaga
authors.affiliation: Department of Animal Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
authors.forename: H
authors.identifier: http://orcid.org/0000-0002-9683-328X
authors.initials: H
authors.lastname: Funahashi
mesh_terms: D000818:Animals; D054885:Cumulus Cells / Q000502:physiology*; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods / Q000662:veterinary*; D008297:Male; D008540:Meiosis; D009865:Oocytes / Q000502:physiology*; D006080:Ovarian Follicle / Q000166:cytology; D013552:Swine / Q000502:physiology*