The fear of experiencing discrimination often provokes symptoms of psychological distress. One coping resource is positive identification with one's social group-known as collective self-esteem. This preliminary study investigated whether collective self-esteem was related to fears regarding a transsexual identity and psychological distress among 53 self-identified male-to-female transsexuals (mean age = 50.79). Participants were recruited from transgender events held in Arizona and California. The majority (81%) reported living full-time as women (mean length of time living as a woman = 6.33 years). Negative feelings about the transsexual community and fears regarding the impact of a transsexual identity were positively related to psychological distress. A regression model revealed that the fear of how a transsexual identity would affect one's life was the best predictor of the severity of psychological distress. These results are consistent with findings from other historically marginalized groups whereby the stress of being stigmatized by society adversely affects mental health.

Development of the mammalian adrenal gland is regulated by a diverse network of growth and transcription factors. Disruptions in these pathways often result in adrenal insufficiency because of adrenal hypoplasia. Several lines of evidence have suggested that the Hedgehog signaling pathway, which controls many aspects of tissue and organ patterning, may play a direct role in adrenal morphogenesis as well. Therefore, we examined the role of Sonic Hedgehog (Shh), a member of the Hedgehog family, in mouse adrenal development. We show that Shh and its downstream effectors Gli1, Gli2, and Gli3 are expressed in the adrenal cortex throughout development, and that Shh is required for normal adrenal organogenesis. Conditional inactivation of Shh in the adrenal cortex using a Cre-loxP system resulted in severe hypoplasia and disorganization of the cortex. In mice carrying the targeted mutation (Shh(fl/fl;SF-1/Cre+)), adrenal mass was significantly reduced and the cortex failed to encapsulate the adrenal medulla. Taken together, these results establish a direct role for Shh signaling in normal adrenal development. genesis 00:1-10, 2009.(c) 2009 Wiley-Liss, Inc.

Premature ovarian failure (POF) is characterized by elevated gonadotropins and amenorrhea in women aged <40 years. In a Lebanese family with five sisters who received the diagnosis of POF, we established linkage to the long arm of the X chromosome (between Xq21.1 and Xq21.3.3), using whole-genome SNP typing and homozygosity-by-descent mapping. By sequencing one candidate gene within that region, POF1B, we identified a point mutation localized in exon 10. This substitution of a nucleotide (G-->A), at position 1123, results in an arginine-->glutamine mutation of the protein sequence at position 329 (mutation R329Q). All the affected family members were homozygous for the mutation, whereas the unaffected members were heterozygous. Because POF1B shares high homology with the tail portion of the human myosin, we assessed the ability of both wild-type and mutant POF1B proteins to bind nonmuscle actin filaments in vitro. We found that the capacity of the mutant protein to bind nonmuscle actin filaments was diminished fourfold compared with the wild type, suggesting a function of POF1B in germ-cell division. Our study suggests that a homozygous point mutation in POF1B influences the pathogenesis of POF by altering POF1B binding to nonmuscle actin filaments.

Some females with little to no risk factors develop prolapse, while other females with multiple risk factors do not. It appears that some women may have a predisposition for prolapse in the setting of equivalent risk factors. We identified 10 patients younger than 55 years old with a family history of prolapse. Their average age was 37 years (range 27-51), the mean number of deliveries was 1.8, and their mean birth weight was 8 lbs. Genetic analysis of the inheritance pattern within these families demonstrated that pelvic organ prolapse segregated in a dominant fashion with incomplete penetrance in these families. Both maternal and paternal transmissions were observed. The relative risk to siblings of affected patients was five times that of the risk for the general population. Further investigation of these families may identify a genetic defect responsible for prolapse.

The central dogma of mammalian brain sexual differentiation has contended that sex steroids of gonadal origin organize the neural circuits of the developing brain . Recent evidence has begun to challenge this idea and has suggested that, independent of the masculinizing effects of gonadal secretions, XY and XX brain cells have different patterns of gene expression that influence their differentiation and function . We have previously shown that specific differences in gene expression exist between male and female developing brains and that these differences precede the influences of gonadal hormones . Here we demonstrate that the Y chromosome-linked, male-determining gene Sry is specifically expressed in the substantia nigra of the adult male rodent in tyrosine hydroxylase-expressing neurons. Furthermore, using antisense oligodeoxynucleotides, we show that Sry downregulation in the substantia nigra causes a statistically significant decrease in tyrosine hydroxylase expression with no overall effect on neuronal numbers and that this decrease leads to motor deficits in male rats. Our studies suggest that Sry directly affects the biochemical properties of the dopaminergic neurons of the nigrostriatal system and the specific motor behaviors they control. These results demonstrate a direct male-specific effect on the brain by a gene encoded only in the male genome, without any mediation by gonadal hormones.

Allele-specific DNA methylation (ASM) is a hallmark of imprinted genes, but ASM in the larger nonimprinted fraction of the genome is less well characterized. Using methylation-sensitive SNP analysis (MSNP), we surveyed the human genome at 50K and 250K resolution, identifying ASM as recurrent genotype call conversions from heterozygosity to homozygosity when genomic DNAs were predigested with the methylation-sensitive restriction enzyme HpaII. Using independent assays, we confirmed ASM at 16 SNP-tagged loci distributed across various chromosomes. At 12 of these loci (75%), the ASM tracked strongly with the sequence of adjacent SNPs. Further analysis showed allele-specific mRNA expression at two loci from this methylation-based screen-the vanin and CYP2A6-CYP2A7 gene clusters-both implicated in traits of medical importance. This recurrent phenomenon of sequence-dependent ASM has practical implications for mapping and interpreting associations of noncoding SNPs and haplotypes with human phenotypes.

Pelvic organ prolapse is a common condition, affecting up to a third of women throughout their lifetime. Genetic factors are believed to account for about 30% of the incidence, and are the least understood component of the disorder. Familial cases, particularly those in which prolapse manifests in young women, are especially valuable in the effort to find the genes involved. We recently reported autosomal dominant transmission as the most likely mode of inheritance, based on a collection of families with high incidence of prolapse. Of greatest interest was a family in which three generations of female relatives suffered from prolapse at a very young age. A genome-wide linkage scan performed using the Affymetrix GeneChip Human mapping 10K array identified ten regions with a LOD score of 1.5, the maximum possible for this family. Candidate genes within those regions were analyzed for expression in vaginal tissue by RT-PCR. Of the genes confirmed to be expressed, LAMC1 was further evaluated by sequencing and select single nucleotide polymorphism (SNP) genotyping for causative sequence variants in affected family members. We identified one such SNP, rs10911193. The rare T variant segregating with the condition is present at a frequency of 4.9% in the general population and 22% among probands from our cohort of families. It affects the binding site for NFIL3, a transcription factor that we verified to be co-expressed in vaginal tissue. Altogether these data suggest that a polymorphism in the promoter of LAMC1 may increase the susceptibility to early-onset pelvic organ prolapse.

Age-related decline in male sex hormones is a direct consequence of testicular aging. These changes in the hormonal complement cause physiological disturbances affecting the quality of life for millions of aging men. To assess the influence on testicular aging of pituitary adenylate cyclase-activating peptide (PACAP), a polypeptide that regulates testicular steroidogenesis in vitro, we compared the testicular structure and function between C57BL/6 wild-type and PACAP(-/-) male mice, at 4 and 15 months of age. We show that, in 4-month-old PACAP(-/-) mice, steroidogenesis (evaluated by levels of testosterone, steroidogenic acute regulatory protein, 3beta-hydroxysteroid dehydrogenase, and P450c17) was impaired. However, the testicular structure of these animals was not affected. At 15 months of age, wild-type testis displayed typical signs of aging (patchy seminiferous tubules, germ cell depletion, and vacuolization), whereas testicular structure was remarkably well conserved in PACAP(-/-) animals. The depletion of germ cells found in wild-type animals was associated with a higher content of peroxynitrites, a marker of reactive oxygen species, and a higher number of apoptotic cells compared with PACAP(-/-) mice. Our results show that testicular aging is delayed in PACAP(-/-) animals. Because the expression levels of steroidogenic factors are low and constant over time in knockout animals, a proposed mechanism for the protection against testicular degeneration is that production of reactive oxygen species, a byproduct of steroidogenesis that induces apoptosis, is down-regulated in PACAP(-/-) animals.

In humans, mutations in the testis-determining gene SRY result in XY sex reversal with pure gonadal dysgenesis (PGD). However, only about 10-15% of the cases of PGD can be explained by mutations within the SRY open reading frame, suggesting the existence of other sex-determining genes. Although SRY is known to bind and bend DNA, its target and mode of action remain elusive. Here, we describe a novel mutation in SRY at codon 127, resulting in a tyrosine (Y) to phenylalanine (F) substitution in the protein. This sequence variant was found not only in the XY female patient but also in her father, who is a phenotypically normal male. However, this Y127F variant was not found in the SRY sequences of 93 other randomly chosen males. This substitution affects a highly conserved tyrosine residue in the HMG box of SRY, in which two de novo mutations have been described previously in XY females with PGD. Furthermore, electromobility shift studies demonstrate that SRY protein harboring the Y127F variant is incapable of binding consensus SRY binding sites in vitro. Taken together, these data suggest that the Y127F variant is a novel mutation with functional consequences and not simply a polymorphism. The allelic variant of SRY transmitted in this family and shared by both a phenotypic female (proband) and a phenotypic male (proband's father) emphasizes the importance of modifier genes in the sex determination pathway.

Human sexual preference is a sexually dimorphic trait with a substantial genetic component. Linkage of male sexual orientation to markers on the X chromosome has been reported in some families. Here, we measured X chromosome inactivation ratios in 97 mothers of homosexual men and 103 age-matched control women without gay sons. The number of women with extreme skewing of X-inactivation was significantly higher in mothers of gay men (13/97=13%) compared to controls (4/103=4%) and increased in mothers with two or more gay sons (10/44=23%). Our findings support a role for the X chromosome in regulating sexual orientation in a subgroup of gay men.

The classic view of brain sexual differentiation and behavior is that gonadal steroid hormones act directly to promote sex differences in neural and behavioral development. In particular, the actions of testosterone and its metabolites induce a masculine pattern of brain development, while inhibiting feminine neural and behavioral patterns of differentiation. However, recent evidence indicates that gonadal hormones may not solely be responsible for sex differences in brain development and behavior between males and females. Here we examine an alternative hypothesis that genes, by directly inducing sexually dimorphic patterns of neural development, can influence the sexual differences between male and female brains. Using microarrays and RT-PCR, we have detected over 50 candidate genes for differential sex expression, and confirmed at least seven murine genes which show differential expression between the developing brains of male and female mice at stage 10.5 days post coitum (dpc), before any gonadal hormone influence. The identification of genes differentially expressed between male and female brains prior to gonadal formation suggests that genetic factors may have roles in influencing brain sexual differentiation.

In most mammals, sex is determined by the presence or absence of the SRY gene. SRY encodes a DNA-binding HMG-box transcription factor which, during embryogenesis, is the initial trigger of testis differentiation from the bipotential gonad, yet its precise mode of function remains unclear. In ovarian development, R-spondin1 and Wnt4 act through the Wnt/beta-catenin-signaling pathway to regulate TCF-dependent expression of unknown target genes and repress testis development. Conversely, SRY may be necessary to prevent the development of ovaries by inhibiting the action of ovarian-determining genes. We hypothesize that SRY prevents Wnt/beta-catenin signaling, thereby inhibiting ovarian development. In HEK293T cells, SRY repressed beta-catenin-mediated TCF-dependent gene activation in the presence of a specific GSK3beta inhibitor or an activated beta-catenin mutant, suggesting that SRY inhibits Wnt signaling at the level of beta-catenin. Three SRY mutant proteins with nuclear localization defects, encoded by XY male-to-female patients, failed to inhibit beta-catenin; surprisingly four SRY sex reversed mutants with defective DNA-binding activity showed near wild-type SRY inhibitory activity. Moreover the potent transactivator SRY-VP16 fusion protein also showed wild-type SRY inhibitory activity. Thus SRY inhibition of beta-catenin involves neither DNA-binding nor transactivation functions of SRY. beta-Catenin and SRY interact in vitro and SRY expression triggered beta-catenin localization into specific nuclear bodies in NT2/D1 and Hela cells. We conclude that SRY inhibits beta-catenin-mediated Wnt signaling by a novel nuclear function of SRY that could be important in sex determination.