Student Profile

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Daniel DeMartini

Graduate Student Researcher

Education

  • B.S., Biochemistry, Brigham Young University-Hawaii, 2004

Research Interests

Cephalopods use controllable iridescence for both communication and camouflage. Iridophores are specialized cells found in the dermis of cephalopods that contain stacks of reflective platelets encased in an organelle called an iridosome. These platelet stacks function as Bragg-like reflectors because of their precise thickness and spacing. Furthermore, by manipulation of the parameters (thickness, spacing, refractive index) the squid are able to selectively control the produced color. The images below (Loligo opalescens) show many iridophore cells and their color ranging from blue to red.

Fig 1

It has been found that unlike other organisms that utilize iridescence (i.e. morpho butterfly, whiptail fish, chameleons, etc), which employ the refractive properties of melanin granules, chitin, or purine crystals, cephalopod reflecting platelets are proteinaceous. The focus of my research is the proteins that make up these optically active structures known as reflectins. Reflectins are a unique family of proteins with no known homologues, no predicted secondary structure, rich in methionine and aromatic residues, high overall charge, and a high overall hydrophilicity. The goal of my research is to further characterize reflectin proteins and identify underlying properties that afford their unique optical characteristics.