| Summary: | 碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 96 === The value of ornamental fish depends on size、appearance、color. Coloration enhancing could bring more value to ornamental fish. Fish coloration depends on more chromatophores which can produce pigment to make high density of pigment or chromatophores distribution on the skin. The coloration in ornamental fish is also regulated by the number of chromatophores, pigmentation regulatary gene, pigment accumulation. The goals of present study are to clone Mitf gene and tyrosinase promoter from goldfish and to employ Chinese herbs, sex hormone, neurotransmitters to regulate coloration in goldfish. A partial tyrosinase promoter is cloned which consisted of 508bp and showing expression of weak activity to regulate expression of GFP by one M-box and three E-box. Partial of Mitf gene is 944bp containing, 7bp in 5’-untranslated region, 937bp in coding region and can be deduced into 312 amino acids. This coding region contains : add domain, exon5b domain, basic helix-loop-helix and leucine-zipper domains. The similarity of parital goldfish Mitf gene with other vertebrates is ranging from 46%~85%, and the similarity of deduced amino acids is ranging from 16%~84%. Mitf mRNA is expressed in eyes, skin, fins and liver tissues which also containing melanin. After fed with Chinese herbs, the expression of Mitf and tyrosinase gene is reduced and the L(black/white) chrominance increased in zebrafish and balck goldfish. After fed with methyltestosterone and norepinephrine, the expression of Mitf and tyrosinase gene increased and the b(blue/yellow) and a(red/green) chrominance increased, meanwhile the L chrominance decreased. The light can decrease the expression of Mitf and tyrosinase gene and increased black/white chrominance.
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