The art and artifact of GDF9 activity: cumulus expansion and the cumulus expansion-enabling factor.
The process of cumulus cell expansion is critical for normal fertility. Oocyte-produced growth and differentiation factor 9 (GDF9) has been thought to play a leading role in this process. Recent studies both support and refute this hypothesis. Central to understanding the physiology of GDF9 is the use of recombinant ligand in in vitro assays. There are several laboratories that currently produce recombinant GDF9 preparations that appear to show variable effects on granulosa cell gene expression and cumulus cell expansion. Several of these studies are reviewed here. Standardization in preparation for recombinant GDF9, as well as a more biochemical analysis of the oocyte-secreted forms of GDF9, may help to resolve the conflicts currently seen in the literature.
Pangas
Stephanie A
SA
Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA. spangas@bcm.tmc.edu
Matzuk
Martin M
MM
D000818:Animals; D055430:Bone Morphogenetic Protein 15; D049109:Cell Proliferation; D005260:Female; D005786:Gene Expression Regulation; D055429:Growth Differentiation Factor 9; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D006080:Ovarian Follicle / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics
C525901:BMP15 protein, human; D055430:Bone Morphogenetic Protein 15; C525897:GDF9 protein, human; D055429:Growth Differentiation Factor 9; D036341:Intercellular Signaling Peptides and Proteins; D011994:Recombinant Proteins