#158 : Whole Transcriptome Analysis of In Vitro-Aged Mouse Oocytes: Effects of Antioxidant Mixture on Oocyte Quality

Abstract

Background and Aims: Aging is known to have negative impacts on oocyte quality. We reported in the previous meeting that the quality of in vitro-aged oocytes was restored by application of a new antioxidant mixture (AOM). Aiming to understand how AOM influenced on oocyte quality, a whole transcriptome analysis was conducted in this study. Method: Using an in vitro aging model, oocytes were collected from superovulated ICR mice, and part of them were cultured for 5h with (AOM group) or without (Aging group) AOM. Oocytes from fresh oocytes (Control group), Aging group and AOM group were subjected to RNA extraction, amplification, and a genechip microarray analysis. Genes expressed with absolute log2 fold change of [Formula: see text] 2 between two groups were designated as differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was conducted for further analysis of DEGs. Results: In vitro aging triggered a total of 643 DEGs when compared with the control group. These DEGs were enriched in 19 biological processes, mostly associated with ribosomal synthesis, metabolic process, response to oxidative stress, apoptosis, signal transduction and mRNA processing. These changes are thought to be related to decreasing oocyte quality. AOM effectively prevented age-related change of those DEGs in a broad spectrum. The genes restored by AOM including Rpl7, Rpl35a, Rpl8, Mt1, Fabp2, Acadm, Hadhb, Gstm4, Ncf4, Ppp3ca, Fzd9, Phka2, Spp1 and Lsm6, are highly associated with cellular homeostatic events, suggesting that AOM not only induces changes of response to oxidative stress, but also normalizes gene expression related to cellular activities resulting in improving oocyte quality. Conclusion: This study strongly suggests that AOM restores the gene expression involved in cellular homeostasis. Also, these findings provide new insights of oocyte quality.