Cloning and sequence analysis of tyrosinase gene in Oujiang color common carp

Abstract:

Oujiang color common carp (Cyprinus carpio var. color) is a regional freshwater species distributed in the Oujiang River basin in China. Due to its rich color patterns and graceful body shape, Oujiang color common carp is a very popular fish to local inhabitants of the Oujiang River drainage. The fish has five kinds of body color patterns, namely “Whole red”, “Whole red with big black patch”, “Whole red with scattered black spots”, “Whole white” and “Whole white with big black patch”. This fish can be a very good model or material for studying body color inheritance in fish. Tyrosinase is a key enzyme involved in the formation of melanin compounds. The melanin can not be synthesized if premature transcription termination occurs in this gene. The cDNA sequences of tyrosinase gene were obtained from the skin tissue of five body color patterns of Oujiang color common carp using the technique of rapid amplification of cDNA ends (RACE). The results showed that the lengths of tyrosinase gene cDNA sequence are different in different color patterns of Oujiang color common carp. For instance, the length of “Whole red” is 2 100 bp, “Whole red with scattered spots” is 2 107 bp, “Whole red with big black patch” is 2 073 bp, “Whole white” is 1 976 bp and “Whole white with big black patch” is 2 111 bp. There are two types of mRNA transcripts in each kind of body color patterns. Analyzing the amino acid sequence from two types mRNA, the first and second structures of predicted protein are different, whereas the third structure and typical structural domain are same in tyrosinase gene. It would be left behind to further research whether the sequence difference of tyrosinase gene would be a direct factor or not in determining different color patterns of Oujiang color common carp.