Search

Schistosoma japonicum causes schistosomiasis in humans and livestock in the Asia-Pacific region. Knowledge of the genome of this parasite should improve understanding of schistosome-host interactions, biomedical aspects of schistosomiasis and invertebrate evolution. We assigned 43,707 expressed sequence tags (ESTs) derived from adult S. japonicum and their eggs to 13,131 gene clusters. Of these, 35% shared no similarity with known genes and 75% had not been reported previously in schistosomes. Notably, S. japonicum encoded mammalian-like receptors for insulin, progesterone, cytokines and neuropeptides, suggesting that host hormones, or endogenous parasite homologs, could orchestrate schistosome development and maturation and that schistosomes modulate anti-parasite immune responses through inhibitors, molecular mimicry and other evasion strategies.

To observe the change of housefly (Musca domestica) breeding in the pig manure treated ecologically with its larvae.The number of eggs and the hatching rate of larvae in the treated manure were compared with that in the untreated manure.The number of eggs laid in the treated manure accounted for only 17.7% of the total eggs, while those in the untreated manure accounted for 82.3%. The hatching rate in the treated manure was 41.4 %, but 85.1% in the untreated manure.There is a significant reduction of eggs laid and of their hatching rate in the pig manure treated ecologically by housefly larvae.

To sub-clone and express the gene encoding Schistosoma japonicum calcium-binding protein (SjE16) and study its immunological response.The specific primers were designed according to the expressed sequence tags (ESTs) sequence, which was used for amplification of the encoding sequence from the cDNA clone containing SjE16. The gene was subcloned into pGEX4T-1 plasmid and expressed. The rSjE16 was tested for its immunological response by ELISA.The gene encoding Schistosoma japonicum SjE16 was cloned and expressed successfully. The immunogenicity and diagnostic potential of rSjE16 were investigated. It was demonstrated by immunoassay in rabbits that the specificity and sensitivity of the test were 94.1% (16/17) and 88.2% (15/17), respectively, and the level of antibody titer of the untreated group reached a peak at 9-11 wk post infection and maintained high at least for 21 wk post infection, while the antibody level in the treated group rapidly decreased to pre-infection level in 11 wk after treatment. In human, the specificity of the test was 98.3% (57/58); the sensitivity of acute and chronic patient serum assay was 85.5% (53/62) and 70.2% (40/57), respectively.The recombinant protein of SjE16 (rSjE16) was acquired. It can be recognized by the sera from schistosomiasis patients, and the level of antibodies decreased quickly after treatment in experimental rabbits, which implicates the potential value for the evaluation of chemotherapy and detection of active infection.

Schistosomiasis remains a serious public health problem with an estimated 200 million people infected in 76 countries. Here we isolated ~ 8,400 potential protein-encoding cDNA contigs from Schistosoma japonicum after sequencing circa 84,000 expressed sequence tags. In tandem, we undertook a high-throughput proteomics approach to characterize the protein expression profiles of a number of developmental stages (cercariae, hepatic schistosomula, female and male adults, eggs, and miracidia) and tissues at the host-parasite interface (eggshell and tegument) by interrogating the protein database deduced from the contigs. Comparative analysis of these transcriptomic and proteomic data, the latter including 3,260 proteins with putative identities, revealed differential expression of genes among the various developmental stages and sexes of S. japonicum and localization of putative secretory and membrane antigens, enzymes, and other gene products on the adult tegument and eggshell, many of which displayed genetic polymorphisms. Numerous S. japonicum genes exhibited high levels of identity with those of their mammalian hosts, whereas many others appeared to be conserved only across the genus Schistosoma or Phylum Platyhelminthes. These findings are expected to provide new insights into the pathophysiology of schistosomiasis and for the development of improved interventions for disease control and will facilitate a more fundamental understanding of schistosome biology, evolution, and the host-parasite interplay., Synopsis Schistosomiasis remains a major public health problem in the developing world. Schistosoma japonicum, the Oriental blood fluke, causes intestinal schistosomiasis in China and the Philippines. Knowledge of the genome and proteome of this worm should improve understanding of biomedical aspects of schistosomiasis. This study represents the first major attempt to characterize the majority of the expressed genes and proteins of a human blood fluke through rigorous, high-throughput genomic and proteomic methodologies. The findings of this study provide a unique resource of numerous schistosome genes and information on protein profiles of the different developmental stages of S. japonicum. Many of the newly discovered proteins are localized on the surface of the worm and its eggs, and they are likely to be involved in the pathogenesis of schistosomiasis. Furthermore, genetic variants found in many of these new genes likely reflect the ability of this important human pathogen to adapt and respond to environmental pressures and the capacity of the parasite to respond to anti-schistosomal therapies. Comparison of these S. japonicum genes with those from mammals and other organisms will facilitate advances in the understanding of blood fluke biology and evolution.