TAp73 is downregulated in oocytes from women of advanced reproductive age.

Studies on oocyte transcriptome are important to understand the biological pathways involved in oogenesis, totipotence and early embryonic development. Moreover, genes regulating physiological pathways in gametes could represent potential candidates for reproductive disorders. In addition to oocyte specific transcription factors, also the members of the p53 family could be etiologically involved due to their biological functions. In fact, their role in the control of cell cycle, apoptosis, and germ-line genome stability is well known. Female reproductive aging is one of the causes of fertility reduction and it is often associated with egg aneuploidy increase. In order to verify the potential involvement of p73 in reproductive aging, we determined its expression in single mature MII oocytes from two groups of women, younger than 35 or older than 38 years, respectively. We found that TAp73 isoforms are down regulated in oocytes from women older than 38 years. We confirmed these data in pools of mouse oocytes. TAp73 down regulation in oocytes from women of advanced reproductive age could explain both the reduction of fertility and the increase of newborns with chromosomal abnormalities.