Timing of anaphase-promoting complex activation in mouse oocytes is predicted by microtubule-kinetochore attachment but not by bivalent alignment or tension

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dc.contributor.authorLane, S.I.R.
dc.contributor.authorYun, Y.
dc.contributor.authorJones, K.T.
dc.date.issued2012
dc.description.abstractHomologous chromosome segregation errors during meiosis I are common and generate aneuploid embryos. Here, we provide a reason for this susceptibility to mis-segregation by live cell imaging of mouse oocytes. Our results show that stable kinetochore-microtubule attachments form in mid-prometaphase, 3-4 hours before anaphase. This coincided with the loss of Mad2 from kinetochores and with the start of anaphase-promoting complex/cyclosome (APC/C)-mediated cyclin B1 destruction. Therefore, the spindle assembly checkpoint (SAC) ceased to inhibit the APC/C from mid-prometaphase. This timing did not coincide with bivalent congression in one-third of all oocytes examined. Non-aligned bivalents were weakly positive for Mad2, under less tension than congressed bivalents and, by live-cell imaging, appeared to be in the process of establishing correct bi-orientation. The time from when the APC/C became active until anaphase onset was affected by the rate of loss of CDK1 activity, rather than by these non-aligned bivalents, which occasionally persisted until anaphase, resulting in homolog non-disjunction. We conclude that, in oocytes, a few erroneous attachments of bivalent kinetochores to microtubules do not generate a sufficient SAC 'wait anaphase' signal to inhibit the APC/C.
dc.description.statementofresponsibilitySimon I. R. Lane, Yan Yun and Keith T. Jones
dc.identifier.citationDevelopment, 2012; 139(11):1947-1955
dc.identifier.doi10.1242/dev.077040
dc.identifier.issn0950-1991
dc.identifier.issn1477-9129
dc.identifier.orcidJones, K.T. [0000-0002-0294-0851]
dc.identifier.urihttp://hdl.handle.net/2440/117682
dc.language.isoen
dc.publisherCompany of Biologists
dc.relation.granthttp://purl.org/au-research/grants/nhmrc/569202
dc.relation.granthttp://purl.org/au-research/grants/arc/DP120100946
dc.rights© 2012. Published by The Company of Biologists Ltd.
dc.source.urihttps://doi.org/10.1242/dev.077040
dc.subjectCell cycle; oocyte; spindle assembly checkpoint; mouse
dc.titleTiming of anaphase-promoting complex activation in mouse oocytes is predicted by microtubule-kinetochore attachment but not by bivalent alignment or tension
dc.typeJournal article
pubs.publication-statusPublished

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