US scientists have replicated a part of a cell, called a mitotic spindle, to better understand its role in cell division. If the spindle doesn’t function properly, the effect could lead to cell death, Down’s Syndrome or cancer.
William Hancock and team at Pennsylvania State University recreated a step in a process called mitosis using the artificial mitotic spindle. Mitosis is when a cell separates the chromosomes in its nucleus into two identical sets in two nuclei. The mitotic spindle, which consists of microtubules, controls the chromosome movement. Microtubules play an important role in the migration of chromosomes to opposite ends of a dividing cell. ‘This work is the first to organise microtubules in vitro into cell-like arrangements with the proper filament polarity and immobilise them in an experimental chamber,’ claims Hancock.
Microtubules are polymers of the protein tubulin. They are inherently polar and can organise themselves into complex geometries in dividing cells. Key characteristics of a mitotic spindle are two spindle poles, oriented microtubules overlapping at the centre, and motor protein activity along the microtubules. To recreate the spindle, Hancock made microscopic electrodes and coated them with proteins binding to one specific end of microtubules. The microtubules were then guided towards these attachment sites using dielectrophoresis and the attached microtubules were extended by additional polymerisation of tubulin.
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Link to journal article
Artificial mitotic spindle generated by dielectrophoresis and protein micropatterning supports bidirectional transport of kinesin-coated beads
Maruti Uppalapati, Ying-Ming Huang, Vidhya Aravamuthan, Thomas N. Jackson and William O. Hancock
Integr. Biol., 2011, DOI: 10.1039/c0ib00065e