碩士 / 國立臺灣海洋大學 / 水產養殖學系 / 94 / Tyrosinase is an important key enzyme in the pathway of melanin metabolism. Tyrosinase catalyzed tyrosine to melanin. The lacks of tyrosinase activity would cause albinism. To study the expression pattern of tyrisinase gene in goldfish and its impacts on the pigmentation process of fish. The tyrosinase full-length cDNA of goldfish was cloned by RT-PCR and RACE method. Analysis of nucleotide sequence revealed that tyrosinase full-length cDNA consists of 1921 bp containing an open reading frame of 1623bp, which encodes 535 amino acids. There is one epidermal growth factor (EGF) like domain and two copper binding domains in the tyrosinase gene sequence. When compared with other vertebrates such as Bos Taurus, Canis familiaris, Coturnix japonica, Denio rerio, Gallus gallus, Homo sapiens, Ictalurus punctatus, Mus musculus, Oncorhynchus mykiss, Oryzias latipes, Oryctolagus cuniculus, Pelodiscus sinensis japonicus, Rana nigromaculata, Sus scrofa and Takifugu rubripes, the identity and similarity of tyrosinase gene ranging from 41% to 84% and 40% to 88%, respectively. In phylogenetic analysis, the goldfish tyrosinase is grouped with Denio rerio, Ictalurus punctatus, Takifugu rubripes, Oncorhynchus mykiss, Takifugu rubripes. The genomic DNA structure of tyrsinase was composed of four exons and three introns. The partial tyrosinase promoter consists of 426 bp containing a E-box(CAGCTG). The higher expression level of goldfish tyrosinase gene was detected in the eye, skin, fin and muscle tissues. Delay the expression of the zebrafish and goldfish tyrosinase gene were observed in embryos when immersed in PTU and Bis solutions. Following embyos immersed in caffeine solution the tyrosinase gene expression in goldfish was increased. Goldfish tyrosinase mRNA level increased following the injection of caffeine and decreased following PTU or Bis injection. Decreasing tyrosinase gene expression was found in the goldfish fed with dopa, PTU, noradrenaline, serotonin, kojic acid, 17α-methyl-testosterone or β-estradiol. U6-anti-tyr-EGFP construct can reduce tyrosinase gene expression and pigmentation in zebrafish.
| Identifer | oai:union.ndltd.org:TW/094NTOU5086047 |
| Date | January 2006 |
| Creators | Pei-Tai Tseng, 曾培臺 |
| Contributors | Jenn-Kan Lu, 陸振岡 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 120 |
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