Molecular cloning and tissue distribution of a Schistosoma japonicum gene encoding AMY-1.

It is well known that the mammalian associate of Myc-1 (AMY-1) plays a significant role in spermatogenesis or cellular differentiation. A full-length complementary DNA (cDNA) encoding AMY-1 of Schistosoma japonicum (SjAMY-1) was identified and isolated from a cDNA library. The gene contained an open reading frame of 315 nucleotides, encoding 105 amino acids. Sequence analysis showed that SjAMY-1 shares 65.7% homology with Homo sapiens AMY-1 amino acids and contains a conserved domain from the AMY-1 family. In this study, we cloned and expressed a recombinant SjAMY-1 (rSjAMY-1) with a molecular size of 14 kDa. The native SjAMY-1 in soluble worm antigen was identified by anti-rSjAMY-1 sera in the Western blot analysis, which demonstrated the presence of this protein in the parasite. Immunofluorescence studies indicated a localization of SjAMY-1 in various tissues and organs including the tegument and subtegumental muscles in adult worms, the ventral sucker in cercariae and the internal structures of eggs. Given the key roles of mammalian AMY-1 in cell proliferation and differentiation, the characterization of SjAMY-1 may allow for a better understanding of the development of S. japonicum.