Linked Life Data

18983844

Source:http://linkedlifedata.com/resource/pubmed/id/18983844

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-12-23
pubmed:abstractText
The objective of this study was to contribute to our understanding of the role of sex steroids in fish sex differentiation and male maturation. Sexually undifferentiated sea bass were administered 17alpha-methyldihydrotestosterone (MDHT), estradiol-17beta (E(2)), fadrozole (Fz), cyproterone acetate (CPA) or tamoxifen (Tx). MDHT produced 100% males whereas E(2) and Tx resulted in 100% females. Fz produced 95% males while CPA did not alter sex ratios. E(2) treatment did not affect gonadal aromatase (cyp19a) expression levels, supporting the possibility that the feminizing effect of exogenous E(2) are not directly related to cyp19a regulation. Both MDHT and Fz decreased cyp19a expression. Moreover, androgen receptor (ar) expression levels increased during development in all but the MDHT group, suggesting that early exposure to an androgen down-regulates subsequent ar expression in males and that Fz does not interact with the androgen receptor. Together, these observations indicate that although MDHT and Fz result in a similar phenotype, the molecular pathways involved are likely different, and show that Fz masculinization is the consequence of inhibited ovarian differentiation rather than of a direct androgenic effect. Further, since CPA did not alter sex ratios when administered during the period of highest androgen sensitivity, we suggest that androgens are not required for initial testicular differentiation in the sea bass. MDHT and Fz did not alter the number of precocious males but reduced and increased, respectively, their gonadosomatic index (GSI). In addition, Fz had lasting effects on the GSI of precocious and non-precocious males, probably due to alterations of estrogen function in the testis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1095-6840
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
160
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3-11
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Masculinization of the European sea bass (Dicentrarchus labrax) by treatment with an androgen or aromatase inhibitor involves different gene expression and has distinct lasting effects on maturation.
pubmed:affiliation
Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Passeig Marítim, Barcelona, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't