Microtubule-severing protein Katanin p60 ATPase-containing subunit A-like 1 is involved in pole-based spindle organization during mouse oocyte meiosis

Abstract

Microtubule-severing proteins (MTSPs) are a group of microtubule-associated proteins essential for multiple microtubule-related processes, including mitosis and meiosis. Katanin p60 ATPase-containing subunit A- like 1 (p60 katanin-like 1) is an MTSP that maintains the density of spindle microtubules at the poles in mitotic cells; however, to date, there have been no studies about its role in female meiosis. Using in vitro-matured (IVM) oocytes as a model, it was first revealed that p60 katanin-like 1 was predominant in the ovaries and oocytes, indicating its essential roles in oocyte meiosis. It was also revealed that p60 katanin-like 1 was concentrated at the spindle poles and co-localized and interacted with β-tubulin, indicating that it may be involved in pole organization. Next, specific siRNA was used to deplete p60 katanin-like 1; the spindle organization was severely disrupted and characterized by an abnormal width:length ratio, multipolarity and extra aster microtubules out of the main spindles. Finally, it was determined that p60 katanin-like 1 knockdown retarded oocyte meiosis, reduced fertilization, and caused abnormal mitochondrial distribution. Collectively, these results indicated that p60 katanin-like 1 is essential for oocyte meiosis by ensuring the integrity of the spindle poles.