Aurora B–mediated localized delays in nuclear envelope formation facilitate inclusion of late-segregating chromosome fragments

Abstract

Acentric chromosomes exhibit delayed segregation during mitosis. How these delays affect nuclear envelope reassembly is not fully understood. Lagging acentrics coated with Aurora B induce a highly localized gap in the nuclear envelope to allow acentric entry into daughter nuclei. Gap formation is decreased upon reduction of Aurora B.

Proliferation of Double-Strand Break-Resistant Polyploid Cells Requires Drosophila FANCD2

“…The Spindle Assembly Checkpoint gene BubR1 was recently shown to function as part of a “tether” connecting acentric DNA and its centromere when breaks are induced during Drosophila neuroblast mitosis (Royou et al 2010; Karg et al 2015; Derive et al 2015). Using the I-Cre1 system, an established method of generating an acentric chromosome (Rong et al 2002; Royou et al 2010), we generated acentric X-chromosomes in diploid neuroblasts.…”

“…BubR1, Polo, and Aurora B respond to broken chromosomes in Drosophila neuroblasts (Royou et al 2010; Karg et al 2015; Derive et al 2015), and Aurora B and INCENP form heterochromatic DNA threads that segregate achiasmate chromosomes during Drosophila meiosis (Hughes et al 2009). Here, we propose that FANCD2 performs a similar function.…”

Revisiting the chromosome separation checkpoint (retrospective on DOI 10.1002/bies.201400140)

“…However, the downstream effectors of Aurora B kinase activity at the midzone responsible for the aneuploidy-preventive effect of the CSC were not identified in the first two studies [2,3]. However, the downstream effectors of Aurora B kinase activity at the midzone responsible for the aneuploidy-preventive effect of the CSC were not identified in the first two studies [2,3].…”

“…Cells have evolved several mechanisms to prevent aneuploidy, such as the spindle assembly checkpoint (SAC). Since then this chromosome separation checkpoint (CSC) was also described for Drosophila, suggesting it to be conserved between species [2]. While the SAC can prevent most mitotic abnormalities, it does not recognize merotelic attachments, in which one of the two sister chromatids is connected to both spindle poles.…”

“…Two years ago, Maiato et al proposed in BioEssays that in human cells a second checkpoint exists that delays chromosome decondensation and nuclear envelope reassembly (NER) when chromosomes lag behind during anaphase [1]. Since then this chromosome separation checkpoint (CSC) was also described for Drosophila, suggesting it to be conserved between species [2].…”