Description
The aim is to determine the molecular and cellular causes of the color of a new breed of bony fish produced by our colleague. He recently cross-bred two species of genus Labeotropheus which produced hybrid offspring whose color was affected by parental gender. One hybrid has a unique color and it was found the color of this novel hybrid animal is associated with an increase in its ability to reflect ultraviolet light. Four pigment molecule types (chromatogens) and skin pigment cell types (chromatophores) are known to be responsible for the myriad of colored appearances of many phylogenetic groups of vertebrates, including several types of bony fish, but not for Labeotropheus or any other genus in this family, Cichlidae. The pigments most likely responsible for the color of the novel hybrid cichlid are the purines, guanine and hypoxanthine, which absorb ultraviolet light and form crystals that reflect visible light. They are normally present in iridophore cells in skin. In this project we will extract prurines from iridophores isolated from the novel fish breed and from normally colored fish, and measure the guanine and hypoxanthine content of the extracts.
Tasks and Responsibilities
The student will assist with the collection of fish skin, isolation of iridophores, preparation of purine extracts, and spectrophotometric analysis of the extracts. This will include preparing some of the materials and reagents required for these procedures, operating the centrifuge during iridophore isolation, ultrafiltration of the extracts, and operation of the analytical spectrophotometer, including calibration and standardization.