@phdthesis{oai:nagoya.repo.nii.ac.jp:00009697, author = {稲垣, 秀人}, month = {Sep}, note = {I have determined the 9.8kb genomic nucleotide sequence of the tyrosinase gene and its 5’ upstream region from a teleost, medakafish (Oryzias latipes), and shown that the coding region is composed of five exons and four introns, spanning 4.7kb. While the number and sizes of the exons were found to be similar to those of mammalian tyrosinase genes, however, the total size of the coding region (4.7kb) was demonstrated to be less than one tenth those of mouse (ca. 70kb) and human (>70kb) genes. Primer extension analysis revealed that the transcription initiation site starts with a long untranslated leader sequence (340 nucleotide long) from the AUG start codon. A characteristic CATGTG sequence known as a putative regulatory motif in melanocyte-specific genes was present in the 131th base upstream from the initiation site, while other typical regulatory elements such as the TATA-box or M-box common to terrestrial vertebrates were lacking. Transgenic experiments were carried out by microinjecting two kinds of plasmid clones into fertilized eggs of the albino i^1 mutant; one consisting of the genomic tyrosinase gene with the 10kb 5’ upstream region, and the other the tyrosinase cDNA with the 3kb 5’ upstream region. The results showed that 53 and 45 of 114 and 118 transgenic eggs, respectively, developed normally beyond hatching and 15 and 10 exhibited a mosaic pattern of pigmentation. Despite the absence of typical regulatory elements like a TATA-box in both cases correct melanin pigmentation was obtained without ectopic expression. Thus, transgenic expression rescued from the albino-i^1 mutation, and the i locus of the medaka genome can be concluded to encode the tyrosinase gene., 名古屋大学博士学位論文 学位の種類:博士(理学) (課程) 学位授与年月日:平成10年9月30日}, school = {名古屋大学, Nagoya University}, title = {The tyrosinase gene from medakafish,Oryzias latipes}, year = {1998} }