Evolutionary and biomedical implications of a Schistosoma japonicum complementary DNA resource

Abstract

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.

Leucine aminopeptidase of the human blood flukes, Schistosoma mansoni and Schistosoma japonicum

“…The recent appearance in GenBank of . 40,000 cDNAs, which may include the complete transcriptome of the adult stage of S. japonicum (Hu et al, 2003), enabled us to re-interrogate the public databases with accession nos. U83906 and AF300423.…”

“…However, by analysing the more recent S. japonicum sequence entries (Hu et al, 2003), we completed the 5 0 end of the LAP gene of this species and identified the start methionine. The protein sequence of the S. japonicum LAP (AF300423) was missing 26 NH 2 -terminal amino acids (see accession no.…”

Schistosomes—proteomics studies for potential novel vaccines and drug targets

“…The use of such strategies permitted the intensive sequencing of schistosomes' genome and transcriptome over the past few years and has greatly influenced the approaches employed to understand parasite biology. Two large-scale, independent, sequencing projects on S. mansoni and japonicum transcriptomes [23,24] allowed, for the first time, a broad sampling of components from the parasites' molecular systems. Analysis of the gene collection represented by the ESTs is based on the inferred functions, which are deduced from alignments of the predicted protein products with proteins of known function from other organisms.…”

“…Therefore, before large-scale sequencing of the parasites' transcriptomes a considerable number of spectra generated by mass spectrometry of schistosome peptides could not be reliably associated with an orthologous protein from public databases. In that scenario, generation of large databases of schistosome coding sequences [23,24] has greatly improved the level of identification in proteomic studies of these organisms.…”

Les génomes des schistosomes : une étape clé dans la lutte contre la bilharziose

“…Initialement focalisé sur le transcriptome, via le séquençage d'Expressed sequence tags [3,4], le projet s'est ensuite orienté vers la cartographie et le séquençage génomique, grâce à la construction de banques de grands fragments dans des Bacterial artificial chromosomes (BAC) [5]. Toutefois, le séquençage complet de certains de ces BAC, ainsi que le séquençage étendu de leurs extrémités, ont démontré l'impossibilité d'effectuer une « marche sur le génome » à cause de la présence massive de séquences répétées.…”