Limits...
Androgen-induced masculinization in rainbow trout results in a marked dysregulation of early gonadal gene expression profiles.

Baron D, Montfort J, Houlgatte R, Fostier A, Guiguen Y - BMC Genomics (2007)

Bottom Line: However, the biological effects of such treatments are poorly understood.The aim of this study was to identify the main effects of an androgen masculinizing treatment (11beta-hydroxyandrostenedione, 11betaOHDelta4, 10 mg/kg of food for 3 months) on gonadal gene expression profiles of an all-female genetic population of trout.Genes considered as muscle fibres markers (GO 'muscle contraction') and genes annotated as structural constituents of the extracellular matrix (GO 'extracellular matrix') or related to meiosis (GO 'chromosome' and 'meiosis') were found significantly enriched in the two clusters of genes specifically up-regulated in androgen-treated female gonads.

View Article: PubMed Central - HTML - PubMed

Affiliation: INRA, UR1037 SCRIBE, IFR140, Ouest-Genopole, F-35000 Rennes, France. daniel.baron@nantes.inserm.fr

ABSTRACT

Background: Fish gonadal sex differentiation is affected by sex steroids treatments providing an efficient strategy to control the sexual phenotype of fish for aquaculture purposes. However, the biological effects of such treatments are poorly understood. The aim of this study was to identify the main effects of an androgen masculinizing treatment (11beta-hydroxyandrostenedione, 11betaOHDelta4, 10 mg/kg of food for 3 months) on gonadal gene expression profiles of an all-female genetic population of trout. To characterize the most important molecular features of this process, we used a large scale gene expression profiling approach using rainbow trout DNA microarrays combined with a detailed gene ontology (GO) analysis.

Results: 2,474 genes were characterized as up-regulated or down-regulated in trout female gonads masculinized by androgen in comparison with control male or female gonads from untreated all-male and all-female genetic populations. These genes were classified in 13 k-means clusters of temporally correlated expression profiles. Gene ontology (GO) data mining revealed that androgen treatment triggers a marked down-regulation of genes potentially involved in early oogenesis processes (GO 'mitotic cell cycle', 'nucleolus'), an up-regulation of the translation machinery (GO 'ribosome') along with a down-regulation of proteolysis (GO 'proteolysis', 'peptidase' and 'metallopeptidase activity'). Genes considered as muscle fibres markers (GO 'muscle contraction') and genes annotated as structural constituents of the extracellular matrix (GO 'extracellular matrix') or related to meiosis (GO 'chromosome' and 'meiosis') were found significantly enriched in the two clusters of genes specifically up-regulated in androgen-treated female gonads. GO annotations 'Sex differentiation' and 'steroid biosynthesis' were enriched in a cluster of genes with high expression levels only in control males. Interestingly none of these genes were stimulated by the masculinizing androgen treatment.

Conclusion: This study provides evidence that androgen masculinization results in a marked dysregulation of early gene expression profiles when compared to natural testicular or ovarian differentiation. Based on these results we suggest that, in our experimental conditions, androgen masculinization proceeds mainly through an early inhibition of female development.

Show MeSH

Related in: MedlinePlus

Gene expression profiles following androgen treatment in female rainbow trout. (A) Heat map of the 2,474 differentially expressed genes in rainbow trout gonads following androgen treatment. The 40 biological samples are ordered according to the experimental groups (red for females; blue for males; black for androgen-treated females) and to the developmental stage (D0 to D110 from left to right). (B) Relative median gene profile of the 13 clusters of temporally correlated gene expression profiles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2099445&req=5

Figure 2: Gene expression profiles following androgen treatment in female rainbow trout. (A) Heat map of the 2,474 differentially expressed genes in rainbow trout gonads following androgen treatment. The 40 biological samples are ordered according to the experimental groups (red for females; blue for males; black for androgen-treated females) and to the developmental stage (D0 to D110 from left to right). (B) Relative median gene profile of the 13 clusters of temporally correlated gene expression profiles.

Mentions: The 2,474 expression profiles were analyzed using a k-means clustering (with k = 13) in order to individualize clusters of genes with similar expression profiles (Fig. 2). These expression profiles and the 13 k-means clusters are available online as a browseable file [12]. Among these clusters, clusters 1 to 4 are characterized by a specific high expression levels of a very large number of genes (N = 1,204) specific to the late ovarian samples (D60 to D110). These clusters could have been merged as their expression profiles seem very similar. In cluster 5 (N = 184) these high expression levels in the female group after D60 are also present in the androgen-treated group after D27. Cluster 6 (N = 89) contains genes with increasing expression profiles starting from D16 in androgen-treated females and from D27 in control males. Clusters 7 (N = 132) and 8 (N = 77) are characterized by an early (starting from D27, cluster 7) or late (starting from D90, cluster 8) increase in gene expression specific to the androgen-treated females. Genes in cluster 9 (N = 214) display a late down-regulation starting from D60 in control female gonads. Cluster 10 (N = 133) is the only cluster that does not show any difference between males, females and androgen-treated females and contains genes with continuously decreasing expression levels from D0 to D110. Cluster 11 (N = 172) contains genes down-regulated both in females (from D60) and androgen-treated females (from D27). Cluster 12 (N = 214) is characterized by gene expression levels specifically down-regulated (from D27) in androgen-treated females. However, this down-regulation is not maintained after the end of the treatment (i.e. after D90). Cluster 13 is the smallest cluster in terms of the number of genes (N = 55) and it displays high expression levels specifically in males throughout all the sampling times (from D0 to D110). Expression levels in androgen-treated females slightly increase after completion of the treatment (> D90).


Androgen-induced masculinization in rainbow trout results in a marked dysregulation of early gonadal gene expression profiles.

Baron D, Montfort J, Houlgatte R, Fostier A, Guiguen Y - BMC Genomics (2007)

Gene expression profiles following androgen treatment in female rainbow trout. (A) Heat map of the 2,474 differentially expressed genes in rainbow trout gonads following androgen treatment. The 40 biological samples are ordered according to the experimental groups (red for females; blue for males; black for androgen-treated females) and to the developmental stage (D0 to D110 from left to right). (B) Relative median gene profile of the 13 clusters of temporally correlated gene expression profiles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2099445&req=5

Figure 2: Gene expression profiles following androgen treatment in female rainbow trout. (A) Heat map of the 2,474 differentially expressed genes in rainbow trout gonads following androgen treatment. The 40 biological samples are ordered according to the experimental groups (red for females; blue for males; black for androgen-treated females) and to the developmental stage (D0 to D110 from left to right). (B) Relative median gene profile of the 13 clusters of temporally correlated gene expression profiles.
Mentions: The 2,474 expression profiles were analyzed using a k-means clustering (with k = 13) in order to individualize clusters of genes with similar expression profiles (Fig. 2). These expression profiles and the 13 k-means clusters are available online as a browseable file [12]. Among these clusters, clusters 1 to 4 are characterized by a specific high expression levels of a very large number of genes (N = 1,204) specific to the late ovarian samples (D60 to D110). These clusters could have been merged as their expression profiles seem very similar. In cluster 5 (N = 184) these high expression levels in the female group after D60 are also present in the androgen-treated group after D27. Cluster 6 (N = 89) contains genes with increasing expression profiles starting from D16 in androgen-treated females and from D27 in control males. Clusters 7 (N = 132) and 8 (N = 77) are characterized by an early (starting from D27, cluster 7) or late (starting from D90, cluster 8) increase in gene expression specific to the androgen-treated females. Genes in cluster 9 (N = 214) display a late down-regulation starting from D60 in control female gonads. Cluster 10 (N = 133) is the only cluster that does not show any difference between males, females and androgen-treated females and contains genes with continuously decreasing expression levels from D0 to D110. Cluster 11 (N = 172) contains genes down-regulated both in females (from D60) and androgen-treated females (from D27). Cluster 12 (N = 214) is characterized by gene expression levels specifically down-regulated (from D27) in androgen-treated females. However, this down-regulation is not maintained after the end of the treatment (i.e. after D90). Cluster 13 is the smallest cluster in terms of the number of genes (N = 55) and it displays high expression levels specifically in males throughout all the sampling times (from D0 to D110). Expression levels in androgen-treated females slightly increase after completion of the treatment (> D90).

Bottom Line: However, the biological effects of such treatments are poorly understood.The aim of this study was to identify the main effects of an androgen masculinizing treatment (11beta-hydroxyandrostenedione, 11betaOHDelta4, 10 mg/kg of food for 3 months) on gonadal gene expression profiles of an all-female genetic population of trout.Genes considered as muscle fibres markers (GO 'muscle contraction') and genes annotated as structural constituents of the extracellular matrix (GO 'extracellular matrix') or related to meiosis (GO 'chromosome' and 'meiosis') were found significantly enriched in the two clusters of genes specifically up-regulated in androgen-treated female gonads.

View Article: PubMed Central - HTML - PubMed

Affiliation: INRA, UR1037 SCRIBE, IFR140, Ouest-Genopole, F-35000 Rennes, France. daniel.baron@nantes.inserm.fr

ABSTRACT

Background: Fish gonadal sex differentiation is affected by sex steroids treatments providing an efficient strategy to control the sexual phenotype of fish for aquaculture purposes. However, the biological effects of such treatments are poorly understood. The aim of this study was to identify the main effects of an androgen masculinizing treatment (11beta-hydroxyandrostenedione, 11betaOHDelta4, 10 mg/kg of food for 3 months) on gonadal gene expression profiles of an all-female genetic population of trout. To characterize the most important molecular features of this process, we used a large scale gene expression profiling approach using rainbow trout DNA microarrays combined with a detailed gene ontology (GO) analysis.

Results: 2,474 genes were characterized as up-regulated or down-regulated in trout female gonads masculinized by androgen in comparison with control male or female gonads from untreated all-male and all-female genetic populations. These genes were classified in 13 k-means clusters of temporally correlated expression profiles. Gene ontology (GO) data mining revealed that androgen treatment triggers a marked down-regulation of genes potentially involved in early oogenesis processes (GO 'mitotic cell cycle', 'nucleolus'), an up-regulation of the translation machinery (GO 'ribosome') along with a down-regulation of proteolysis (GO 'proteolysis', 'peptidase' and 'metallopeptidase activity'). Genes considered as muscle fibres markers (GO 'muscle contraction') and genes annotated as structural constituents of the extracellular matrix (GO 'extracellular matrix') or related to meiosis (GO 'chromosome' and 'meiosis') were found significantly enriched in the two clusters of genes specifically up-regulated in androgen-treated female gonads. GO annotations 'Sex differentiation' and 'steroid biosynthesis' were enriched in a cluster of genes with high expression levels only in control males. Interestingly none of these genes were stimulated by the masculinizing androgen treatment.

Conclusion: This study provides evidence that androgen masculinization results in a marked dysregulation of early gene expression profiles when compared to natural testicular or ovarian differentiation. Based on these results we suggest that, in our experimental conditions, androgen masculinization proceeds mainly through an early inhibition of female development.

Show MeSH
Related in: MedlinePlus