Chromatophore

Each organism has its unique and specific characteristics that have a great impact on the survival and adaptation processes. One of the most amazing and remarkable characteristics in some organisms such as crustaceans, cephalopods and some insects is the reversible color change property in their skin. This color change happens for various reasons such as thermoregulation, camouflage, and mating. It occurs due to the existence of the chromatophore, which is a special sort of pigment cells in their skin compositions. Chameleons are one of the most spectacular organisms that have this unique capability. This paper aims to demonstrate the property of chameleon’ reversible color change skin, its mechanism, and its applications in Architecture. In order to achieve this goal, different types of materials and glazing technologies that imitate this property and their applications in building’s skin have been displayed. Besides, a schematic proposed framework inspired from the chameleon’ skin...

Animal breeding hobbyists have been useful to science because they identify and isolate color coat mutations that geneticists can in turn use in their studies of the development and differentiation of color cells. This paper discusses a very interesting color mutant, the Japanese Galaxy, tracing its creation from back to a self-educated genetics hobbyist, Hoskiki Tsutsui. The paper discusses a constituent gene previously studied by Dr. Violet Phang, the snakeskin gene (the linked body and fin genes Ssb and Sst). And it discusses a gene previously unknown to science, the Schimmelpfennig Platinum gene (Sc). Through crossing experiments, the author determines that the combination of these two genes produces an intermediate phenotype, the Medusa. Incorporating the Grass (Gr, another gene unknown to science) gene into the Medusa through a crossover produces the Galaxy phenotype. Microscope studies of the snakeskin pattern in Galaxies and snakeskins reveals some parallels with similar studies made of the Zebrafish Danio.

Factors which influence physiological color change in leeches was studied using the Hogben and Slome chromatophore  index. Leeches disperse their pigments in the light and concentrate them in the dark. They do no background adapt but do respond to changes in light intensity. Ligation experiments implicate a neurohormonal mechanism. The response revolved de novo in the Rhynchobdellida (Glossiphoniidae and Piscicolidae).

Using Ham's F-12 medium, an in vitro culture system permitting cellular survival for over 6 months has been developed for the chromatophores of the guppy. In this culture system, the various types of chromatophores (melanophores, erythrophores and xanthophores) migrated out of the explanted tail fin tissue, retained their pigmentation, and displayed both mitotic and pigment-translocating activities. The mitotic activity was evident during the first 3 or 4 weeks in culture, whereas the pigment-translocating ability persisted for 16 weeks. The cultured chromatophores of male fish displayed pigment aggregation in response to adrenergic agents (epinephrine and norepinephrine) and pigment dispersion in response to alpha-melanocyte stimulating hormone (alpha-MSH), cyclic AMP and dibutyryl cyclic AMP. Cyclic GMP did not elicit pigment-translocating responses in any of the chromatophores.

The chromatophores of Rhodobacter (Rb.) sphaeroides represent a minimal bio-energetic system, which efficiently converts light energy into usable chemical energy. Despite extensive studies, several issues pertaining to the morphology and molecular architecture of this elemental energy conversion system remain controversial or unknown. To tackle these issues, we combined electron microscope tomography, immuno-electron microscopy and atomic force microscopy. We found that the intracellular Rb. sphaeroides chromatophores form a continuous reticulum rather than existing as discrete vesicles. We also found that the cytochrome bc1 complex localizes to fragile chromatophore regions, which most likely constitute the tubular structures that interconnect the vesicles in the reticulum. In contrast, the peripheral light-harvesting complex 2 (LH2) is preferentially hexagonally packed within the convex vesicular regions of the membrane network. Based on these observations, we propose that the bc1...