Question

The distribution of melanosomes in cells is tightly regulated in animals that rapidly change color. dark-colored cells have melanosomes scattered throughout the cytoplasm while light-colored cells have them aggregated near the nucleus. how could cells use microtubules and motor proteins to change the distribution of melanosomes?

Answer 1

Microtubules originate on the centre of the cell taking the positive end to the periphery of the cell, while the negative end remains turned to the centre of the cell. The melanosomes move along these microtubules using motor proteins desiganted kinesins and dyneins. The kinesins are responsible for moving the melanosomes to the positive end of the microtubule (periphery of the cell) generating dark-colored cells, whereas dyneins move the melanosomes to the negative end of the microtubule (centre of the cell) generating light-colored cells.