title: Regulation of human and mouse oocyte maturation in vitro with 6-dimethylaminopurine.
abstract: It has been postulated that premature shortening of the oocyte growth phase due to the recovery of oocytes from small diameter follicles may be responsible for the developmental anomalies associated with in-vitro maturation. 6-Dimethylaminopurine (DMAP) was used to artificially lengthen the pre-maturation period of oocyte growth, in vitro, by inhibiting germinal vesicle breakdown in mouse and human oocytes. DMAP inhibited the meiotic maturation of mouse and human oocytes and the inhibition was fully reversible. The timing of polar body extrusion was accelerated in mouse oocytes following the withdrawal of DMAP; however, the kinetics of nuclear maturation in human oocytes was unaffected by exposure to DMAP. All mouse and human DMAP-treated oocytes that matured to metaphase II expressed histone H1 kinase activity. Fertilization rates in both DMAP-treated and control mouse and human oocytes were comparable, and human embryonic development was similar in control and DMAP-treated oocytes. However, blastocyst development was significantly reduced in DMAP-treated mouse oocytes (P < 0.05). It is concluded that lengthening the prematuration growth phase, by temporarily inhibiting kinase activity with DMAP, does not directly improve oocyte developmental competence but provides a useful tool for further investigating meiotic and developmentally related events in vitro by manipulating meiotic resumption.
authors.affiliation: Centre for Early Human Development, Institute of Reproduction and Development, Monash University, Monash Medical Centre, Clayton, Victoria, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Anderiesz
authors.forename: C Y
authors.initials: CY
authors.lastname: Fong
authors.forename: A
authors.initials: A
authors.lastname: Bongso
authors.forename: A O
authors.initials: AO
authors.lastname: Trounson
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007700:Kinetics; D008540:Meiosis / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009865:Oocytes / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development*; D010766:Phosphorylation; D014176:Protein Biosynthesis / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D019926:Cyclin B; D004791:Enzyme Inhibitors; C001020:N(6),N(6)-dimethyladenine; D011494:Protein Kinases; C102333:histone H1 kinase; D016203:CDC2 Protein Kinase; D000225:Adenine