F-Actin nucleated on chromosomes coordinates their capture by microtubules in oocyte meiosis.

ABSTRACT: Capture of each and every chromosome by spindle microtubules is essential to prevent chromosome loss and aneuploidy. In somatic cells, astral microtubules search and capture chromosomes forming lateral attachments to kinetochores. However, this mechanism alone is insufficient in large oocytes. We have previously shown that a contractile F-actin network is additionally required to collect chromosomes scattered in the 70-µm starfish oocyte nucleus. How this F-actin-driven mechanism is coordinated with microtubule capture remained unknown. Here, we show that after nuclear envelope breakdown Arp2/3-nucleated F-actin "patches" form around chromosomes in a Ran-GTP-dependent manner, and we propose that these structures sterically block kinetochore-microtubule attachments. Once F-actin-driven chro

SUBMITTER: Burdyniuk M 

PROVIDER: S-EPMC6080919 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature