In vitro follicle growth under non-attachment conditions and decreased FSH levels reduces Lhcgr expression in cumulus cells and promotes oocyte developmental competence

• DOI: 10.1007/s10815-011-9690-x
• Publication Date: 2011-12-21T14:04:07Z
• Authors: Flor Sánchez; Sergio Romero; Firas K. Albuz; Johan Smitz
• Keywords: 0303 health sciences; Cumulus Cells; follicle culture; Cell Culture Techniques; Gene Expression; Gene Expression Regulation, Developmental; Fertilization in Vitro; Receptors, LH; Mice, Inbred C57BL; Mice; 03 medical and health sciences; Luteinizing hormone receptor; Ovarian Follicle; Oocyte competence; Oocytes; Animals; Female; follicle-stimulating hormone; Follicle Stimulating Hormone

The in-vitro environment influences oocyte competence and gene expression in cumulus cells and oocytes. Effects of culturing under non-attachment conditions and varying follicle exposure to FSH were investigated at the mRNA level and on oocyte developmental capacity.Quantitative PCR analysis of Gdf9, Mater, Nmp2 (in oocytes), Lhcgr and Amh (in cumulus cells), and oocyte developmental competence after in vitro follicle culture were evaluated.Follicle survival (98.7%) and polar body rate (94%) were similar for all conditions. Estradiol and progesterone production were significantly lower in non-attachment follicles (10-fold and 3-fold, respectively). Under non-attachment conditions, a higher two-cell rate (69.9%) and total blastocyst yield (48.5%) were obtained and, by decreasing FSH levels during culture, Lhcgr transcripts were significantly reduced to levels similar to in-vivo. Levels of oocyte-specific transcripts were not significantly influenced by in-vitro conditions.Non-attachment conditions influence follicle steroid secretory capacity and, together with dynamic FSH doses, positively influence cumulus cell gene expression and oocyte developmental competence.