Phylogeny of tyrosinase gene

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Body color of higher animals is primarily determined by melanin pigment. The pigment is deposited in an organelle called melanosome in a specifically differentiated cell, melanosome. Tyrosinase is one of melanosomal proteins and well known as the key enzyme for melanin pigment biosynthesis.In this report, two closely interrelated aspects are focused. One of those aims is to discover transacting factors which guarantee coordinate gene expression for metanization ; We have so far detected two protein molecules which bind 5 regulatory sequences of two different genes which both code melanosomal proteins. Another aspect is to commence studying emergence and evolutionary track of melanocyte.Here we report cloning and sequencing of two non-mammalian tyrosinase genes from Japanese quail and snap turtle.Genomic sequences of tyrosinase genes which contain 5' upstream regions, the first exons and a part of the first introns from Japanese quail and a snap turtle did not show high homology to those of higher animals. Although there were relatively low similarity seen at the leader sequences, the first exons were highly conserved both at the nucleotide position of putative initiation sites and the exon/intron border.It is interesting to see whether or not those regulatory region of non-mamalian tyrosinase genes can function in mammalian melanocytes. To answer such a question commence to elucidate the evolutionary conserved(or formed)identity of melanocyte in animals.