Screening of ovarian steroidogenic pathway in Ciona intestinalis and its modulation after tributyltin exposure

Journal Article · Sat May 15 00:00:00 EDT 2010 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/j.taap.2010.03.001· OSTI ID:21344955

Cangialosi, Maria Vittoria; Puccia, Egidio ^[1]; Mazzola, Antonio ^[2]; Mansueto, Valentina ^[1]; Arukwe, Augustine ^[3]

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1. Department of Animal Biology 'G. Reverberi', University of Palermo (Italy)
2. Department of Ecology, University of Palermo (Italy)
3. Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim (Norway)

In this study, we have identified several ovarian steroids in Ciona with high similarity to vertebrate steroids and showed that cholesterol, corticosterone, dehydroepiandrosterone, estrone, estradiol-17beta, testosterone, pregnenolone, progesterone, have identical molecular spectra with vertebrate steroids. In addition, we have studied the effects of an endocrine disruptor (tributyltin: TBT) on these sex hormones and their precursors, ovarian morphology, and gene expression of some key enzymes in steroidogenic pathway in the ovary of Ciona. Ovarian specimens were cultured in vitro using different concentrations of TBT (10{sup -5}, 10{sup -4} and 10{sup -3} M). Ethanol was used as solvent control. Gene expression analysis was performed for adrenodoxin (ADREN) and adrenodoxin reductase (ADOX) (mediators of acute steroidogenesis) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD). These transcripts were detected and measured by quantitative (real-time) polymerase chain reaction (qPCR). Sex steroids and their precursors were identified and quantified by a gas chromatography-mass spectroscopy (GC-MS) method. Exposure of Ciona ovaries to TBT produced modulations (either increased or decreased) of sterols and sex steroid levels, whereas no significant differences in ADREN, ADOX or 17beta-HSD mRNA expression patterns were observed. Histological analysis shows that TBT produced several modifications on Ciona ovarian morphology that includes irregular outline of nuclear membrane, less compacted cytoplasm, in addition to test and granulosa cells that were detached from the oocyte membrane. Given that the ascidians represent very simple experimental models for the study of endocrine disruption by environmental contaminants, our findings provide excellent models for multiple identification and quantification of sex steroid and their precursors in biological samples exposed to endocrine-disrupting chemicals and for direct extrapolation of such effects across taxonomic groups and phyla. In addition, these results suggest that Cionaintestinalis may be a suitable species for molecular ecotoxicological studies and biomarker model for endocrine-disrupting effects in marine invertebrates.

• OSTI ID: 21344955
• Journal Information: Toxicology and Applied Pharmacology, Vol. 245, Issue 1; Other Information: DOI: 10.1016/j.taap.2010.03.001; PII: S0041-008X(10)00086-4; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BIOLOGICAL MARKERS
CHOLESTEROL
CORTICOSTERONE
ESTRADIOL
ESTRONE
GAS CHROMATOGRAPHY
HYDROXYANDROSTENONE
HYDROXYPREGNENONE
IN VITRO
MASS SPECTROSCOPY
MESSENGER-RNA
OVARIES
PRECURSOR
PROGESTERONE
SCREENING
TESTOSTERONE
ADRENAL HORMONES
ANDROGENS
ANDROSTANES
BODY
CHROMATOGRAPHY
CORTICOSTEROIDS
ESTRANES
ESTROGENS
FEMALE GENITALS
GLUCOCORTICOIDS
GONADS
HORMONES
HYDROXY COMPOUNDS
KETONES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PREGNANES
RNA
SEPARATION PROCESSES
SPECTROSCOPY
STEROID HORMONES
STEROIDS
STEROLS