Cytoskeletal mechanisms for platelet production.

Platelets release from megakaryocytes living primarily in the bone marrrow space. Intermediates in platelet formation are proplatelets, long tube-like processes that are extended by microtubule-based forces hundreds of micrometers from the megakaryocyte cell body. Granules and organelles enter the proplatelets and traffic up and down on their microtubules to be ultimately delivered to the platelet buds before they release. How individual platelets form and release from proplatelets remains poorly understood.