Microtubules are of fundamental biological importance.
Fertilization depends on sperm motility and oocyte transport generated by microtubules in cilia and flagella. Cells can not multiply without microtubules to faithfully transport chromosomes to the daughter cells. Nervous systems do not survive without microtubules to transport supplies made in the cell body to and from distant synaptic contacts. Their function is unknown. This hypothesis is being tested by looking at the effects of failed processing on microtubule organization in vivo and in vitro.