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

Sequence Corner

Abstract

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.

Keywords

Schistosomiasis Computational molecular biology Schistosoma genetics Egg formation 

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

References

  1. Altschul SF, Madden TL, Schaffer AA, Zhang J, Zhang Z, Miller W et al (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25:3389–3402PubMedGoogle Scholar
  2. Bobek L, Rekosh DM, Keulen H, LoVerde PT (1986) Characterization of a female-specific cDNA derived from a developmentally regulated mRNA in the human blood fluke Schistosoma mansoni. Proc Natl Acad Sci USA 83:5544–5548Google Scholar
  3. Bobek LA, Rekosh DM, LoVerde PR (1988) Small gene family encoding an eggshell (Chorion) protein of the human parasite Schistosoma mansoni. Mol Cell Biol 8:3008–3016Google Scholar
  4. Bobek LA, LoVerde PT, Rekosh DM (1989) Schistosoma haematobium: analysis of eggshell protein genes and their expression. Exp Parasitol 68:17–30Google Scholar
  5. Chen LL, Rekosh DM, LoVerde PT (1992) Schistosoma mansoni p48 eggshell protein gene: characterization, developmentally regulated expression and comparison to the p14 eggshell protein gene. Mol Biochem Parasitol 52:39–52Google Scholar
  6. Johnson KS, Taylor DW, Cordingley JS (1987) Possible eggshell protein gene from Schistosoma mansoni. Mol Biochem Parasitol 22:89–100Google Scholar
  7. Köster B, Dargatz H, Schroder J, Hirzmann J, Haarmann C, Symmons P et al (1988) Identification and localisation of the products of a putative eggshell precursor gene in the vitellarium of Schistosoma mansoni. Mol Biochem Parasitol 31:183–198Google Scholar
  8. Merrick JM, Osman A, Tsai J, Quackenbush J, LoVerde PT, Lee NH (2003) The Schistosoma mansoni gene index: gene discovery and biology by reconstruction and analysis of expressed gene sequences. J Parasitol 89:261–269Google Scholar
  9. Michel A, Knobloch J, Kunz W (2003) P19: a female and tissue specifically expressed gene in Schistosoma mansoni, regulated by pairing with the male. Parasitol 127:519–524Google Scholar
  10. Reis MG, Kuhns J, Blanton R, Davis AH (1989) Localization and pattern of expression of a female specific mRNA in Schistosoma mansoni. Mol Biochem Parasitol 32:113–119Google Scholar
  11. Sugiyama H, Kawanaka M, Kameoka Y, Nakamura M (1997) A novel cDNA clone of Schistosoma japonicum encoding the 34,000 Dalton eggshell precursor protein. Int J Parasitol 27:811–817Google Scholar
  12. Waite JH, Rice-Ficht AC (1992) Eggshell precursor proteins of Fasciola hepatica. II. Microheterogeneity in vitelline protein B. Mol Biochem Parasitol 54:143–151CrossRefPubMedGoogle Scholar
  13. Wells KE, Cordingley JS (1991) Eggshell formation is regulated by pH and calcium. Exp Parasitol 73:295–310Google Scholar

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

Personalised recommendations