,

David Nesvorný1, William F Bottke, Luke Dones

  • 1Southwest Research Institute, 1050 Walnut St, Suite 426, Boulder, Colorado 80302, USA. davidn@boulder.swri.edu

Nature
|June 18, 2002
PubMed
まとめ

科学者たちは580万年前に形成された若い小惑星一族を発見し,衝突の出来事への希少な見方を提供しました. その最小限の進化は,元の衝突特性と小惑星の再蓄積の研究を可能にします.

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Separation of Sister Chromatids02:17

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At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
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Microtubules form through the end-to-end polymerization of tubulin heterodimers. Kinetochore microtubules originate from the spindle poles, and their plus-ends connect with the kinetochores on sister-chromatids. Ndc80 protein complexes, present on the kinetochore, form low-affinity links with the plus end of these kinetochore microtubules.
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