Could comparison of oocyte gene expression enhance pre-clinical validation of vitrification protocols?

 

PRE-CLINICAL VALIDATION:  

• mRNA expression may indicate developmental competence
• measurement of mRNA expression not yet included as standard

STUDY DESIGN: Three experiments used sibling oocyte experimental design.

• 1. vitrified and non-vitrified MII failed-to-fertilize oocytes
• 2. open (Cryoleaf) and closed (Rapid-i) vitrification systems
• 3. different media using the closed system.

METHODS:

• PolyA PCR and QPCR
• Thermo cycler cut-off point as constant point of comparison
• Limited statistical analysis avoided distortion of results
• Graphical presentation of results to avoid distortion

RESULTS: Different protocols and media, same closed device

• media 2 higher mean expression of OCT4, FIGLα, ZAR1, MAD2, SOD2
• greater number of oocytes expressed mRNA of all target genes
• variability in gene expression noticeably less in media 2 oocytes

INTERPRETATION OF RESULTS:

• Evidence of developmental capacity - or its loss?
• Knowledge rapidly evolving e.g. mRNA, molecular level
• Technologies rapidly evolving e.g.  transcriptomics, dehydration

POTENTIAL USES OF METHOD:

• pre-clinical validation of media and devices under development
• comparative assessments of existing optimised protocols

FURTHER INFORMATION ABOUT METHOD AND RESULTS: https://research.manchester.ac.uk/en/studentTheses/impact-of-oocyte-vitrification