Development Genes and Evolution

, Volume 215, Issue 5, pp 261–267 | Cite as

Cracks in the shell—zooming in on eggshell formation in the human parasite Schistosoma mansoni

  • Ingo Ebersberger
  • Jürgen Knobloch
  • Werner Kunz
Sequence Corner


Schistosomiasis, currently the second most common parasitic disease of humans in tropical regions is caused by the eggs of trematode worms of the genus Schistosoma. Understanding egg formation and specifically the synthesis of the eggshell comprises, consequently, a promising starting point to cure and prevent the disease. To shed light on the genetics of the latter process, we analysed the three known S. mansoni eggshell proteins P14, P19 and P48 against the background of the species’ inferred proteome and of eggshell proteins identified in other trematode species. Our results suggest that eggshell formation in Schistosoma involves a multitude of different proteins organised in currently three distinct protein families (P14, P48 and P34 eggshell protein family). The first two families are of simple structure. Their respective members share a substantial degree of sequence similarity and are, to date, observed only in the genus Schistosoma. In contrast, the P34 family of eggshell proteins is complex. Its in part highly diverged members share only a conserved motif of 67-aa length on average and are detected in various trematode species. The resulting widespread occurrence of this protein motif suggests an important role during eggshell formation in trematodes. Screening more than 7,000 putative proteins of S. mansoni, we could identify six new members of the P34 protein family that are likely to be involved in eggshell formation in this species.


Schistosomiasis Computational molecular biology Schistosoma genetics Egg formation 



The authors thank Arndt von Haeseler and two anonymous reviewers for helpful comments on the manuscript.

Supplementary material

S1 Alignment of the transcript encoding SmP19 (Z27402), a related transcript from the S. mansoni gene index (TC7414) and the corresponding region from the S. mansoni genome. Z27402 differs by three deletions and one insertion from TC7414 and the genomic sequence, which result in four shifts of the reading frame

S2 Genomic organization of six putative members of the P34 eggshell protein family. Putative start and stop codons, TATA boxes, and polyadenylation signals are underlined

S3 Hydropathy plots of the eight members of the P34 eggshell protein family in S. mansoni


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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Ingo Ebersberger
    • 1
  • Jürgen Knobloch
    • 2
  • Werner Kunz
    • 3
  1. 1.Institute for BioinformaticsHeinrich Heine UniversityDüsseldorfGermany
  2. 2.Institute for Animal Developmental and Molecular BiologyHeinrich Heine UniversityDüsseldorfGermany
  3. 3.Institute for GeneticsHeinrich Heine UniversityDüsseldorfGermany

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