title: Maturation of human cumulus-free germinal vesicle-stage oocytes to metaphase II by coculture with monolayer Vero cells.
abstract: The objective of this study was to evaluate and compare the efficacy of coculture with Vero cells (monkey kidney cells) and in-vitro culture in B2 Ménézo medium for the maturation of germinal vesicle (GV)-stage cumulus-free human oocytes to metaphase II. Cumulus-free human GV-stage oocytes obtained after ovulation induction and retrieval via vaginal ultrasound echo-guided puncture were put either in coculture with Vero cells or in 25 microliters droplets of B2 Ménézo medium. In a controlled randomized study, 145 GV-stage oocytes were matured in vitro: 72 were placed in the coculture system with Vero cells and 73 were cultured in B2 alone. After 30 h of in-vitro culture, 82.4% had dissolved the nuclear membrane and extruded the first polar body in the coculture system compared with 37% in B2 medium (P < 0.001). A significant difference was also noticed in the number of GV-stage oocytes which underwent GV breakdown; the proportion of oocytes which did not extrude the first polar body (metaphase I) was 1.6% in the coculture system compared to 44.0% in the B2 medium. It can be concluded that coculture with Vero cells improves the in-vitro maturation of cumulus-free human GV-stage oocytes.
authors.affiliation: Centre for Reproductive Medicine, University Hospital, Dutch-speaking Brussels Free University (Vrije Universiteit Brussel), Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Janssenswillen
authors.forename: Z P
authors.initials: ZP
authors.lastname: Nagy
authors.forename: A
authors.initials: A
authors.lastname: Van Steirteghem
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D016922:Cellular Senescence; D002522:Chlorocebus aethiops; D003584:Cytological Techniques; D005260:Female; D008677:Metaphase; D009865:Oocytes / Q000502:physiology*; D014709:Vero Cells