PUBLICATION
Growth Differentiation Factor 9 and Its Spatiotemporal Expression and Regulation in the Zebrafish Ovary
- Authors
- Liu, L., and Ge, W.
- ID
- ZDB-PUB-061116-5
- Date
- 2007
- Source
- Biology of reproduction 76(2): 294-302 (Journal)
- Registered Authors
- Ge, Wei
- Keywords
- Ovary, Follicle, Growth factors, Oocyte development
- MeSH Terms
-
- Animals
- Blotting, Northern
- Cloning, Molecular
- Down-Regulation
- Embryo, Nonmammalian/metabolism
- Embryonic Development
- Female
- Fertilization
- Gastrulation
- Growth Differentiation Factor 9/genetics
- Growth Differentiation Factor 9/metabolism*
- In Situ Hybridization
- Oocytes/metabolism
- Oocytes/physiology
- Ovarian Follicle/metabolism
- Ovary/metabolism*
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Tissue Distribution
- Zebrafish/metabolism*
- PubMed
- 17093199 Full text @ Biol. Reprod.
Citation
Liu, L., and Ge, W. (2007) Growth Differentiation Factor 9 and Its Spatiotemporal Expression and Regulation in the Zebrafish Ovary. Biology of reproduction. 76(2):294-302.
Abstract
Growth differentiation factor 9 (GDF9) is a member of the transforming growth factor beta (TGFB) superfamily. As an oocyte-specific growth factor, GDF9 plays critical roles in controlling folliculogenesis in mammals. In the present study, we cloned a cDNA (2100 bp) of zebrafish GDF9 homolog (Gdf9, gdf9), which shows ~60% homology with that of mammals in the mature region. RT-PCR analysis showed that zebrafish gdf9 expression could only be detected in the gonads, and Northern blot analysis revealed one single transcript (about 2.0 kb) in the ovary. Real-time RT-PCR analysis demonstrated that gdf9 had the highest expression in the primary growth (PG, Stage I) follicles, and its expression level gradually decreased during follicle development with the level being the lowest in the full-grown (FG) follicles. The expression of gdf9 maintained through fertilization and early embryonic development until gastrulation when the expression level dramatically decreased. The expression became barely detectable after late gastrula stage. Within the follicle, gdf9 mRNA was localized exclusively in the oocytes as demonstrated by RT-PCR on denuded oocytes and freshly isolated follicle layers as well as in situ hybridization. Interestingly, when amplified at high cycle numbers, the expression of gdf9 could also be detected in cultured zebrafish follicle cells that were free of oocytes. The expression of gdf9 could be down-regulated by hCG in both ovarian fragments and isolated follicles in a dose and time-dependent manner, and the inhibition appeared to be stage-dependent with the strongest inhibition observed in the FG follicles and no effect in the PG follicles. This correlates well with the expression profile of LH receptor (lhcgr) in the zebrafish follicles. In conclusion, as an oocyte-derived growth factor, GDF9 is well conserved across vertebrates. With its biological advantages, zebrafish will provide an alternative model for further studying its function and regulation.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping