Prc1-rich kinetochores are required for error-free acentrosomal spindle bipolarization during meiosis I in mouse oocytes
Authors: Sui Nishiyama
Shu Hashimoto
Hirohisa Kyogoku
Takaya Abe
Mary Herbert
Shuhei Yoshida
Tappei Mishina
Aurélien Courtois
Lisa Lister
Meenakshi Choudhary
Tomoya S Kitajima
Aki Shiraishi
Yoshiharu Nakaoka
Journal: Nature Communications (2020)
Discipline: Multidisciplinary
Keywords: acentrosomal meiosis; spindle bipolarization; kinetochores; microtubule nucleation; Prc1
Affiliations: Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, 650-0047, Japan., Graduate School of Biostudies, Kyoto University, 606-8501, Kyoto, Japan., Biosciences Institute, Newcastle University, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK., Newcastle Fertility Centre, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK., Graduate School of Medicine, Osaka City University, Osaka, 545-8585, Japan., IVF Namba Clinic, Osaka, 550-0015, Japan., Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, 650-0047, Japan., Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, 650-0047, Japan. ., Graduate School of Biostudies, Kyoto University, 606-8501, Kyoto, Japan. .

Abstract:  Acentrosomal meiosis in oocytes represents a gametogenic challenge, requiring spindle bipolarization without predefined bipolar cues. While much is known about the structures that promote acentrosomal microtubule nucleation, less is known about the structures that mediate spindle bipolarization in mammalian oocytes. Here, we show that in mouse oocytes, kinetochores are required for spindle bipolarization in meiosis I. This process is promoted by oocyte-specific, microtubule-independent enrichment of the antiparallel microtubule crosslinker Prc1 at kinetochores via the Ndc80 complex. In contrast, in meiosis II, cytoplasm that contains upregulated factors including Prc1 supports kinetochore-independent pathways for spindle bipolarization. The kinetochore-dependent mode of spindle bipolarization is required for meiosis I to prevent chromosome segregation errors. Human oocytes, where spindle bipolarization is reportedly error prone, exhibit no detectable kinetochore enrichment of Prc1. This study reveals an oocyte-specific function of kinetochores in acentrosomal spindle bipolarization in mice, and provides insights into the error-prone nature of human oocytes. 

Retracted: No

PubPeer comments:
 Concern about Figure 4C. * Sharp vertical transitions appear to be visible. Shown with small orange arrows. * Several bands appear to be visible multiple times within the same blot, in both blots. Arrows of the same color highlight similar bands. ![file] Repetitive bands appear to be visible in Figure 5 as well. Could the authors please explain what happened here? , 
 This article does have a correction, but that was to address a mistake in the unit of agmatine doses. See: https: doi.org 10.1007 s10571-018-0604-7 The text of the correction is as follows:  The original version of this article unfortunately contained a mistake in the unit of agmatine doses. The agmatine doses were erroneously written in nanomolar in the published arti- cle. The correct effective doses of agmatine were 150 and 250 u03bcM. ,