Biobites

Bridges Between Cells Unlocking New Understandings Inside Them Though most mammals, including humans, are born with one skin colour for the rest of their lives, there lives a variety of species that are able to change their colour in order to blend in with their surroundings. Amphibians, fish, and reptiles make up a large component of these animals, with the chromatophore organelle present within their cells that allows them to rapidly change colour. One of the few classifications of this organelle, are melanophores, which are what regulate pigmentation in the zebrafish, a model organism used in many research experiments (Eom et al., 2012). While the study of pigments and colour change is only a growing study, there are many practical uses that are being discovered that could benefit the understanding of the cell. The melanin that dictates pigment of the human skin, as well as the scales of various amphibians and fish is produced in the melanosome organelles. These organelles are moved through the cell using the microtubules of the cytoskeleton. Through the research of rapid colour changing organisms, there is a possibility for better understanding how not only melanophores, but other substances are transported in cells. Using the ATP produced by the cell, the various nutrients and proteins are driven along the tubules of the cytoskeleton to various parts in need of the cargo (Bouzat et al., 2012). Among these nutrients and proteins is melanin. Melanin is what is used to respond to and protect against UV radiation in animals. Though melanosomes are only produced in specialized cells known as melanocytes, the pigments that they produce travel to other cells of the lower epidermis by ways of the cytoskeletons and cytoplasmic extensions. Since many mammals do not have a very striking redistribution of melanocytes than that of amphibians and fish, the latter are more targeted for research than their warm blooded counterparts. Even though the melanin is

References: Bouzat S, Levi V, Bruno L (2012). Transport Properties of Melanosomes along Microtubules Interpreted by a Tug-of-War Model with Loose Mechanical Coupling. PLoS ONE 7(8), 1-16 Eom, D., Inoue, S., Patterson, L., Gordon, T., Slingwine, R. (2012). Melanophore Migration and Survival during Zebrafish Adult Pigment Stripe Development Require the Immunoglobulin Superfamily Adhesion Molecule Igsf11. PLoS Genetics, 8(8), 1-14 Seabra, M.C., Hume, A. (2011). Melanosomes on the Move: A Model to Understand Organelle Dynamics. Biochemical Society Interactions, 39(5), 1191-1196