title: Cytoplasmic, rather than nuclear-DNA, insufficiencies as the major cause of poor competence of vitrified oocytes.
abstract: To unravel the differential contributions of nuclear-DNA and cytoplasm to the poor 'competence' of oocytes after cryopreservation, reciprocal exchange of metaphase II-spindle chromosomal complex (karyoplast) between vitrified and fresh oocytes was carried out in an ovine animal model. Karyoplast exchange per se was accomplished with high efficiency and in-vitro development of oocytes reconstituted with fresh-karyoplast and vitrified-cytoplast (FK/VC) showed no improvement over VK/VC and control-vitrification oocytes. Blastocyst development of oocytes that were reconstituted with vitrified-karyoplast and fresh-cytoplast (VK/FC) approached that of fresh-controls, however, and was significantly higher than FK/VC, VK/VC, and control-vitrification (all P ≤ 0.05). These results point toward 'cytoplasmic insufficiencies' as the main cause of poor 'competence' of matured oocytes after vitrification.
authors.affiliation: Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Biotechnology, ACECR, P.O. Box 81593-58686, Isfahan, Iran. Electronic address: smhosseini@royaninstitute.org.
authors.forename: Sayyed Morteza
authors.initials: SM
authors.lastname: Hosseini
authors.affiliation: Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Biotechnology, ACECR, P.O. Box 81593-58686, Isfahan, Iran.
authors.forename: Vajihe
authors.initials: V
authors.lastname: Asgari
authors.affiliation: Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Biotechnology, ACECR, P.O. Box 81593-58686, Isfahan, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Hajian
authors.affiliation: Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Biotechnology, ACECR, P.O. Box 81593-58686, Isfahan, Iran. Electronic address: mh.nasr-esfahani@royaninstitute.org.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Nasr-Esfahani
mesh_terms: D002467:Cell Nucleus / Q000235:genetics*; D003593:Cytoplasm / Q000235:genetics*; D004247:DNA / Q000235:genetics*; D005260:Female; D006801:Humans; D009865:Oocytes / Q000166:cytology*; D058989:Vitrification
chemical_list: D004247:DNA
keywords: cytoplasmic deficiencies; karyoplast transplantation; oocyte; vitrification