merotelic

The extreme stretching of most centromeres is likely accompanied by a deformed/disrupted kinetochore structure, which precludes identification of most merotelic kihetochores by EM in fig. 5C-E.

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

To the contrary, we have found that unresolved merotelic attachment, as opposed to continuing pairing of sister chromatids after anaphase onset, is the primary contributor to missegregation that is accompanied by DNA damage late in mitosis.

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

The EM images (Fig. 5) collectively reinforce the correlation between stretching of centromeric chromatin, spreading of microtubule-binding modules of individual kinetochores and a net increase in uncorrected syntelic, merotelic, and double-merotelic attachments in condensin-depleted cells.

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

Aurora B activity in correcting syntelic and merotelic attachments

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

Most merotelic attachments in wild type affect only one sister kinetochore and are corrected prior to anaphase, any (few) remaining mis-attachments are resolved upon application of anaphase pulling forces

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

Thus, condensin dysfunction synergistically induces merotelic attachments and compromises the merotelic attachment correction mechanism, leading to chromosome breaks and nondisjunction.

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

Knowlton AL, Lan W, Stukenberg PT (2006) Aurora B is enriched at merotelic attachment sites, where it regulates MCAK.

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

When condensins are depleted, the resulting dispersed microtubule attachment sites mediate massive merotelic attachments.

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

The insert schematic shows the arrangement of a merotelic kinetochore with attached microtubules.

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009

While it is plausible that the stretched kinetochores in condensin-depleted chromatin have disoriented microtubule-binding sites that facilitate merotelic attachments, why would such mis-attachments remain uncorrected in metaphase and anaphase?

PLoS ONE Alerts: New Articles Alexander Samoshkin et al. 2009