Possible role of microtubules in vesicular transport of matrix protein during sea urchin larval biomineralization

We propose that vesicles bearing matrix proteins are trafficked on microtubules to the spicule cavity where their exocytosis is assisted by focal adhesions. The role of microtubules in biomineralization from unicellular algae to human bones suggests that the proposed microtubule-guided vesicle transport into the biomineralization compartment could be a common mechanism in Eukaryotes' biomineralization.