Molecular aspects of Schistosoma mansoni female maturation

Ana Lúcia Moraes Giannini Sérgio Vasconcelos Linhares Elena Cristina Caride Vânia Maria Martins Braga Franklin David Rumjanek About the authors

Abstract

Incubation of total protein extracts of Schistosoma mansoni with 3H 17-beta-estradiol and 20-hydroxyecdysone, revealed steroid binding proteins in both, male and female worms. The interaction of nuclear proteins with restriction fragments of the gender and stage-specific gene F-10 was investigated using the "Band-Shift" technique. Distinct male and female nuclear proteins bound to the fragments of this gene. Among the nuclear proteins, only those rich in cysteine residues bound to DNA. In vitro incubation of live worms with the estrogen antagonist Tamoxifen, altered the pattern of the DNA binding proteins, producing in females, a band profile similar to that obtained with male worm protein extracts. When Tamoxifen was injected into schistosome infected mice, the eggs produced by females presented an abnormal morphology, compatible with non-viable eggs. These results suggest that the regulation of transcription of the F-10 gene might involve steroid receptors.

Schistosoma mansoni; nuclear proteins; F-10 gene; steroid receptors; Tamoxifen; eggs


ABSTRACT

Molecular aspects of Schistosoma mansoni female maturation

Ana Lúcia Moraes Giannini1

Sérgio Vasconcelos Linhares1

Elena Cristina Caride1

Vânia Maria Martins Braga1

Franklin David Rumjanek1

Universidade Federal do Rio de Janeiro, ICB/CSS, Departamento de Bioquímica Médica, Rio de Janeiro, Brasil

Incubation of total protein extracts of Schistosoma mansoni with 3H 17-beta-estradiol and 20-hydroxyecdysone, revealed steroid binding proteins in both, male and female worms. The interaction of nuclear proteins with restriction fragments of the gender and stage-specific gene F-10 was investigated using the "Band-Shift" technique. Distinct male and female nuclear proteins bound to the fragments of this gene. Among the nuclear proteins, only those rich in cysteine residues bound to DNA. In vitro incubation of live worms with the estrogen antagonist Tamoxifen, altered the pattern of the DNA binding proteins, producing in females, a band profile similar to that obtained with male worm protein extracts. When Tamoxifen was injected into schistosome infected mice, the eggs produced by females presented an abnormal morphology, compatible with non-viable eggs. These results suggest that the regulation of transcription of the F-10 gene might involve steroid receptors.

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Publication Dates

  • Publication in this collection
    01 June 2009
  • Date of issue
    Apr 1995
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