Kinetochore

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Kinetochores are found on the centromere of sister chromatids.
Their main use is for the accurate alignment of chromosomes which is essential to avoid birth defects by having genomic stability and correct gene transmission.
The chromosome is connected to the Spindle Fibres by their being to the Kinetochore and this interaction allows for segregation of chromosome during mitosis and meiosis [1].

After DNA replication, sister chromotids are present within a cell. These are held together by a region called the centromere and this is the assembly site for the kinetochore- a protein complex.
Kinetochores are giant multilayer protein structures that have an ability to attach microtubule at a protein collar on the kinetochore. As the kinetochore holds the microtubulin tightly in place, addition and removal of tubulin units at the plus end of the microtubulin coordinates the movement of chromosomes during division. This movement occurs on the spindle that is formed across the cell. Bipolar attachments are formed at the kinetochore on either side of a sister chromatid and this is the reason that the chromatids can be pulled apart- they are drawn from each side and forced to separate [2].

Reference

  1. Wadsworth centre, New York State Department of Health, Using Electron tomography to assess kinetochore modulation of microtubule dynamics. Available at: http://www.wadsworth.org/rvbc/kineto.htm (last accessed 14.11.11)
  2. Alberts et al. 2007: 1082
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