Spindle dynamics has a critical role in many physiological mechanisms such as genomic integrity and aging. It is also well known that these mechanisms affect oocyte quality. Because the oocyte quality affects fertility and embryo development, many efforts have been conducted to understand the molecular mechanisms that regulate spindle dynamics during oocyte maturation. Here, we show that translationally controlled tumor protein (TCTP) regulates spindle dynamics during oocyte maturation and prevents deterioration of oocyte quality during postovulatory aging. TCTP was expressed and localized at the cytoplasm with strong enrichment at the spindle microtubules during meiosis. Through the knockdown of TCTP, we found that TCTP regulated stability of the polar microtubules. Meanwhile, spindle dynamics were dramatically decreased with reduced TCTP level during the postovulatory oocyte aging both in vitro and in vivo. Knockdown of TCTP accelerated the reduction of spindle dynamics and aging-related quality deterioration of oocytes. Conversely, overexpression of TCTP rescued microtubule dynamics during postovulatory aging of oocytes and prevented aging-induced deterioration of quality. In addition, overexpression of TCTP improved fertilization competency and subsequent embryonic development. Therefore, our results demonstrate that TCTP is a microtubule-associating protein required to regulate spindle dynamics in mouse oocytes and protects oocytes from aging-related quality deterioration.

• Hyuk Joon Jeon(Molecular Biology of Development and Reproduction)
• Jeong Su Oh(Department of Genetic Engineering, Sungkyunkwan University)