Superovulation alters telomere length and telomerase component levels in mouse oocytes

Assisted reproductive technologies (ARTs) are widely used to treat infertility and include the fundamental step, controlled ovarian stimulation (also known as superovulation). Superovulation involves the administration of gonadotropins to produce a sufficient number of oocytes, either through single or repeated applications. However, superovulation can cause certain adverse effects such as increased oxidative stress, decreased oocyte quality, and mitochondrial dysfunction. As oxidative stress and mitochondrial dysfunction are closely associated with alterations in telomere length, we investigated the effects of single and repeated superovulation on expression of the telomerase components and telomere length in mouse oocytes at germinal vesicle (GV) or metaphase II (MII) stage. Additionally, we measured serum levels of estradiol, progesterone, and oxidative markers. Our findings revealed that superovulation significantly affected telomere length, TERT protein level, telomerase RNA component (Terc), and telomerase reverse transcriptase (Tert) mRNA levels in these oocytes possibly due to altered estradiol and progesterone profiles (P < 0.05). These results suggest that altered telomerase expression and telomere length may contribute to emerging adverse effects of superovulation during oocyte maturation and early embryo development.