Genomic assessment of follicular marker genes as pregnancy predictors for human IVF. Hamel M et al. Embryo selection efficiency in human IVF procedure is still suboptimal as shown by low pregnancy rates with single embryo transfer (SET). Bidirectional communication between the oocyte and follicular cells (FC) is essential to achieve developmental competence of the oocyte. Differences in the gene expression profile of FCs from follicles leading to pregnancy could provide useful markers of oocyte developmental competence. FCs were recovered by individual follicle puncture. FC expression levels of potential markers were assessed by Q-PCR with an intra-patient and an inter-patient analysis approach. Using gene expression, a predictive model of ongoing pregnancy was investigated. Using intra-patient analysis, 4 candidate genes, phosphoglycerate kinase 1 (PGK1), regulator of G-protein signalling 2 (RGS2), regulator of G-protein signalling 3 (RGS3) and cell division cycle 42 (CDC42) showed a difference between FCs from follicles leading to a pregnancy or developmental failure. The best predictors for ongoing pregnancy were PGK1 and RGS2. Additionally, inter-patient analysis revealed differences in FC expression for PGK1 and CDC42 between follicles leading to a transferred embryo with positive pregnancy results and those with negative results. Both inter-patient and intra-patient approaches must be taken into consideration to delineate gene expression variations in the context of follicular competence. A predictor model using biomarkers could improve the efficiency of predicting developmental competence of oocytes. These new approaches provide useful tools in the context of embryo selection and in the improvement of pregnancy rates with SET.
Expression regulated by
LH
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Ovarian localization
Granulosa
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Changes in mouse granulosa cell gene expression during early luteinization. McRae RS et al. Changes in gene expression during granulosa cell luteinization have been measured using serial analysis of gene expression (SAGE). Immature normal mice were treated with pregnant mare serum gonadotropin (PMSG) or PMSG followed, 48 h later, by human chorionic gonadotropin (hCG). Granulosa cells were collected from preovulatory follicles after PMSG injection or PMSG/hCG injection and SAGE libraries generated from the isolated mRNA. The combined libraries contained 105,224 tags representing 40,248 unique transcripts. Overall, 715 transcripts showed a significant difference in abundance between the two libraries of which 216 were significantly down-regulated by hCG and 499 were significantly up-regulated. Among transcripts differentially regulated, there were clear and expected changes in genes involved in steroidogenesis as well as clusters of genes involved in modeling of the extracellular matrix, regulation of the cytoskeleton and intra and intercellular signaling. The SAGE libraries described here provide a base for functional investigation of the regulation of granulosa cell luteinization.