MYC integrates FSH signalling networks in cumulus cells during bovine oocyte maturation

Area of Science:

• Reproductive Biology
• Molecular Endocrinology
• Genomics

Background:

• Follicle-stimulating hormone (FSH) is crucial for oocyte maturation and competence acquisition.
• The transcription factors (TFs) orchestrating FSH-mediated gene expression changes in cumulus cells (CCs) remain largely uncharacterized.
• Understanding these TFs is vital for improving in vitro maturation (IVM) protocols.

Purpose of the Study:

• To identify transcription factors involved in FSH-mediated signaling during bovine oocyte in vitro maturation (IVM).
• To investigate the roles of MYC and THAP11 (RONIN) in response to FSH stimulation in CCs.
• To explore potential post-translational modifications and protein interactions regulating FSH signaling.

Main Methods:

• Bovine cumulus-oocyte complexes (COCs) were matured in vitro with or without FSH for 22 hours.
• Gene expression profiling of cumulus cells was performed.
• Bioinformatic tools were used to identify candidate TFs, predict binding motifs, and analyze protein-protein interactions.

Main Results:

• MYC expression was significantly downregulated (0.35-fold) while THAP11 (RONIN) expression was upregulated (1.47-fold) under FSH stimulation.
• In silico analysis predicted binding sites for known FSH-responsive TFs in MYC and THAP11 genes.
• MYC and THAP11 proteins possess potential phosphorylation sites, suggesting regulation by signaling pathways like PKA, ERK, and p38.

Conclusions:

• MYC and THAP11 are key transcription factors responsive to FSH during bovine oocyte IVM.
• MYC appears to integrate FSH signaling networks, potentially driving genome-wide transcriptional changes for oocyte competence.
• THAP11 acts independently, suggesting complex regulatory mechanisms underlying FSH action in cumulus cells.