Cloning and expression of astacin gene in albino and normal sea cucumber (Apostichopus japonicus Selenka)
刺参虾青素基因的克隆及不同体色个体间表达差异的分析

In normal individuals of Apostichopus japonicus, dorsal and ventral surfaces turn yellowish brown in color. However, in albino individuals, little pigment is deposited on their dorsal and ventral surfaces, and the offspring also suffer from albinism. To investigate the correlation between astacin gene expression and albinism in A. japonicus, we cloned the astacin full-length cDNA of A. japonicus and analyzed the differences of astacin mRNA expression in the adult body wall and juveniles between albino and normal individuals. The full-length cDNA of A. japonicus astacin contained 2058 nucleotides that encodes an astacin protein of 560 amino acids. The real-time PCR analysis showed that astacin expression levels were significantly lower in albino adults compared to normal adults. In A. japonicus juveniles, compared to normal juveniles the astacin expression levels were significantly lower in albino individuals by 39 days after fertilization. We therefore suggest that the albinism in A. japonicus might be due to low astacin expression.