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Disorders of sex development expose transcriptional autonomy of genetic sex and androgen-programmed hormonal sex in human blood leukocytes.

Holterhus PM, Bebermeier JH, Werner R, Demeter J, Richter-Unruh A, Cario G, Appari M, Siebert R, Riepe F, Brooks JD, Hiort O - BMC Genomics (2009)

Bottom Line: Gender appears to be determined by independent programs controlled by the sex-chromosomes and by androgen-dependent programming during embryonic development.However, a significantly larger gene set in the PBMC only reflected the degree of external genital masculinization independent of the sex chromosomes and independent of concurrent post-natal sex steroid hormone levels.A significant fraction of gene expression differences between males and females in the human appears to have its roots in early embryogenesis and is not only caused by sex chromosomes but also by long-term sex-specific hormonal programming due to presence or absence of androgen during the time of external genital masculinization.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pediatrics, Christian Albrechts University of Kiel, Germany. holterhus@pediatrics.uni-kiel.de

ABSTRACT

Background: Gender appears to be determined by independent programs controlled by the sex-chromosomes and by androgen-dependent programming during embryonic development. To enable experimental dissection of these components in the human, we performed genome-wide profiling of the transcriptomes of peripheral blood mononuclear cells (PBMC) in patients with rare defined "disorders of sex development" (DSD, e.g., 46, XY-females due to defective androgen biosynthesis) compared to normal 46, XY-males and 46, XX-females.

Results: A discrete set of transcripts was directly correlated with XY or XX genotypes in all individuals independent of male or female phenotype of the external genitalia. However, a significantly larger gene set in the PBMC only reflected the degree of external genital masculinization independent of the sex chromosomes and independent of concurrent post-natal sex steroid hormone levels. Consequently, the architecture of the transcriptional PBMC-"sexes" was either male, female or even "intersex" with a discordant alignment of the DSD individuals' genetic and hormonal sex signatures.

Conclusion: A significant fraction of gene expression differences between males and females in the human appears to have its roots in early embryogenesis and is not only caused by sex chromosomes but also by long-term sex-specific hormonal programming due to presence or absence of androgen during the time of external genital masculinization. Genetic sex and the androgen milieu during embryonic development might therefore independently modulate functional traits, phenotype and diseases associated with male or female gender as well as with DSD conditions.

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Ratio of FZD6 transcript levels in 2 46,XY normal males (N-003; N-015) and 46,XX strongly virilized females (P-103; P-105) compared with two 46,XX normal females (N-020; N-031) and two 46,XY females (P-019; P-033) by semi-quantitative RT-PCR. The y-axis reflects the ratios of expression levels of the normal male – and the strongly virilized DSD individuals, respectively, divided through the phenotypic female individuals (normal females and 46,XY-sex reversed females) as indicated. RT-PCR confirms higher expression of FZD6 in virilized individuals.
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Figure 2: Ratio of FZD6 transcript levels in 2 46,XY normal males (N-003; N-015) and 46,XX strongly virilized females (P-103; P-105) compared with two 46,XX normal females (N-020; N-031) and two 46,XY females (P-019; P-033) by semi-quantitative RT-PCR. The y-axis reflects the ratios of expression levels of the normal male – and the strongly virilized DSD individuals, respectively, divided through the phenotypic female individuals (normal females and 46,XY-sex reversed females) as indicated. RT-PCR confirms higher expression of FZD6 in virilized individuals.

Mentions: Within each of the 46,XX and 46,XY groups were 2 subgroups that largely correlated with the degree of genital masculinization (Figure 1B, F, G). The 46,XX normal female subjects clustered separately from the three 46,XX subjects with genital masculinization and CAH based on differences in expression across 146 of the 157 sex-specific transcripts. Similarly, the 46,XY individuals separated into a group comprised of normal males and highly masculinized individuals with DSD (with one exception) and a group with predominantly female external genitalia, again based on expression differences across the same 146 transcripts. Only two patients did not follow this pattern. Subject P-115, who clustered with phenotypic males, had 46,XY DSD and Prader 1–2 genitalia due to an unclassified defect in androgen biosynthesis. Subject P-088 had mixed gonadal dysgenesis due to 45,X0/46,XY mosaicism and Prader 4 genitalia yet clustered with phenotypic females. Since mosaicism can vary between tissue compartments and since developmental genes may modify the site-specific expression level of the androgen receptor in the external genitalia [21,22], some discrepancies between genital phenotype and systemic androgenization are not unexpected. Using qRT-PCR, we evaluated transcript levels of FZD6 (Frizzled 6), since levels measured by microarray analysis correlated with genital phenotype (Figure 1G). Similar to the microarray experiments, mean FZD6 transcript levels were significantly higher in normal 46,XY-males and in strongly virilized 46,XX-CAH females compared with normal 46,XX-females and 46,XY DSD-females (Figure 2).


Disorders of sex development expose transcriptional autonomy of genetic sex and androgen-programmed hormonal sex in human blood leukocytes.

Holterhus PM, Bebermeier JH, Werner R, Demeter J, Richter-Unruh A, Cario G, Appari M, Siebert R, Riepe F, Brooks JD, Hiort O - BMC Genomics (2009)

Ratio of FZD6 transcript levels in 2 46,XY normal males (N-003; N-015) and 46,XX strongly virilized females (P-103; P-105) compared with two 46,XX normal females (N-020; N-031) and two 46,XY females (P-019; P-033) by semi-quantitative RT-PCR. The y-axis reflects the ratios of expression levels of the normal male – and the strongly virilized DSD individuals, respectively, divided through the phenotypic female individuals (normal females and 46,XY-sex reversed females) as indicated. RT-PCR confirms higher expression of FZD6 in virilized individuals.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2713997&req=5

Figure 2: Ratio of FZD6 transcript levels in 2 46,XY normal males (N-003; N-015) and 46,XX strongly virilized females (P-103; P-105) compared with two 46,XX normal females (N-020; N-031) and two 46,XY females (P-019; P-033) by semi-quantitative RT-PCR. The y-axis reflects the ratios of expression levels of the normal male – and the strongly virilized DSD individuals, respectively, divided through the phenotypic female individuals (normal females and 46,XY-sex reversed females) as indicated. RT-PCR confirms higher expression of FZD6 in virilized individuals.
Mentions: Within each of the 46,XX and 46,XY groups were 2 subgroups that largely correlated with the degree of genital masculinization (Figure 1B, F, G). The 46,XX normal female subjects clustered separately from the three 46,XX subjects with genital masculinization and CAH based on differences in expression across 146 of the 157 sex-specific transcripts. Similarly, the 46,XY individuals separated into a group comprised of normal males and highly masculinized individuals with DSD (with one exception) and a group with predominantly female external genitalia, again based on expression differences across the same 146 transcripts. Only two patients did not follow this pattern. Subject P-115, who clustered with phenotypic males, had 46,XY DSD and Prader 1–2 genitalia due to an unclassified defect in androgen biosynthesis. Subject P-088 had mixed gonadal dysgenesis due to 45,X0/46,XY mosaicism and Prader 4 genitalia yet clustered with phenotypic females. Since mosaicism can vary between tissue compartments and since developmental genes may modify the site-specific expression level of the androgen receptor in the external genitalia [21,22], some discrepancies between genital phenotype and systemic androgenization are not unexpected. Using qRT-PCR, we evaluated transcript levels of FZD6 (Frizzled 6), since levels measured by microarray analysis correlated with genital phenotype (Figure 1G). Similar to the microarray experiments, mean FZD6 transcript levels were significantly higher in normal 46,XY-males and in strongly virilized 46,XX-CAH females compared with normal 46,XX-females and 46,XY DSD-females (Figure 2).

Bottom Line: Gender appears to be determined by independent programs controlled by the sex-chromosomes and by androgen-dependent programming during embryonic development.However, a significantly larger gene set in the PBMC only reflected the degree of external genital masculinization independent of the sex chromosomes and independent of concurrent post-natal sex steroid hormone levels.A significant fraction of gene expression differences between males and females in the human appears to have its roots in early embryogenesis and is not only caused by sex chromosomes but also by long-term sex-specific hormonal programming due to presence or absence of androgen during the time of external genital masculinization.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pediatrics, Christian Albrechts University of Kiel, Germany. holterhus@pediatrics.uni-kiel.de

ABSTRACT

Background: Gender appears to be determined by independent programs controlled by the sex-chromosomes and by androgen-dependent programming during embryonic development. To enable experimental dissection of these components in the human, we performed genome-wide profiling of the transcriptomes of peripheral blood mononuclear cells (PBMC) in patients with rare defined "disorders of sex development" (DSD, e.g., 46, XY-females due to defective androgen biosynthesis) compared to normal 46, XY-males and 46, XX-females.

Results: A discrete set of transcripts was directly correlated with XY or XX genotypes in all individuals independent of male or female phenotype of the external genitalia. However, a significantly larger gene set in the PBMC only reflected the degree of external genital masculinization independent of the sex chromosomes and independent of concurrent post-natal sex steroid hormone levels. Consequently, the architecture of the transcriptional PBMC-"sexes" was either male, female or even "intersex" with a discordant alignment of the DSD individuals' genetic and hormonal sex signatures.

Conclusion: A significant fraction of gene expression differences between males and females in the human appears to have its roots in early embryogenesis and is not only caused by sex chromosomes but also by long-term sex-specific hormonal programming due to presence or absence of androgen during the time of external genital masculinization. Genetic sex and the androgen milieu during embryonic development might therefore independently modulate functional traits, phenotype and diseases associated with male or female gender as well as with DSD conditions.

Show MeSH
Related in: MedlinePlus