title: Failure to launch: aberrant cumulus gene expression during oocyte in vitro maturation.
abstract: In vitro maturation (IVM) offers significant benefits for human infertility treatment and animal breeding, but this potential is yet to be fully realised due to reduced oocyte developmental competence in comparison with in vivo matured oocytes. Cumulus cells occupy an essential position in determining oocyte developmental competence. Here we have examined the areas of deficient gene expression, as determined within microarrays primarily from cumulus cells of mouse COCs, but also other species, between in vivo matured and in vitro matured oocytes. By retrospectively analysing the literature, directed by focussing on downregulated genes, we provide an insight as to why the in vitro cumulus cells fail to support full oocyte potential and dissect molecular pathways that have important roles in oocyte competence. We conclude that the roles of epidermal growth factor signalling, the expanded extracellular matrix, cumulus cell metabolism and the immune system are critical deficiencies in cumulus cells of IVM COCs.
authors.affiliation: The Robinson Research InstituteSchool of Medicine.|Australian Research Council Centre of Excellence for Nanoscale BioPhotonicsThe University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Brown
authors.affiliation: The Robinson Research InstituteSchool of Medicine.
authors.forename: Kylie R
authors.initials: KR
authors.lastname: Dunning
authors.affiliation: The Robinson Research InstituteSchool of Medicine.|Australian Research Council Centre of Excellence for Nanoscale BioPhotonicsThe University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Melanie
authors.initials: M
authors.lastname: Sutton-McDowall
authors.affiliation: Discipline of Obstetrics and GynaecologySchool of Women's and Children's Health, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Gilchrist
authors.affiliation: The Robinson Research InstituteSchool of Medicine.|Australian Research Council Centre of Excellence for Nanoscale BioPhotonicsThe University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Jeremy G
authors.initials: JG
authors.lastname: Thompson
authors.affiliation: The Robinson Research InstituteSchool of Medicine darryl.russell@adelaide.edu.au.
authors.forename: Darryl L
authors.initials: DL
authors.lastname: Russell
mesh_terms: D000818:Animals; D054885:Cumulus Cells / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism; D009866:Oogenesis / Q000502:physiology*