Parentage-based pedigree reconstruction reveals female matrilineal clusters and male-biased dispersal in nongregarious Asian great apes, the Bornean orang-utans (Pongo pygmaeus).

Philopatry and sex-biased dispersal have a strong influence on population genetic structure, so the study of species dispersal patterns and evolutionary mechanisms shaping them are of great interest. Particularly nongregarious mammalian species present an underexplored field of study: despite their lower levels of sociality compared to group-living species, interactions among individuals do occur, providing opportunities for cryptic kin selection. Among the least gregarious primates are orang-utans (genus: Pongo), in which preferential associations among females have nevertheless been observed, but for which the presence of kin structures was so far unresolved because of the equivocal results of previous genetic studies. To clarify relatedness and dispersal patterns in orang-utans, we examined the largest longitudinal set of individuals with combined genetic, spatial and behavioural data. We found that males had significantly higher mitochondrial DNA (mtDNA) variation and more unique haplotypes, thus underscoring their different maternal ancestries compared to females. Moreover, pedigree reconstruction based on 24 highly polymorphic microsatellite markers and mtDNA haplotypes demonstrated the presence of three matrilineal clusters of generally highly related females with substantially overlapping ranges. In orang-utans and possibly other nongregarious species, comparing average biparental relatedness (r) of males and females to infer sex-biased dispersal is extremely problematic. This is because the opportunistic sampling regime frequently employed in nongregarious species, combined with overlapping space use of distinct matrilineal clusters, leads to a strong downward bias when mtDNA lineage membership is ignored. Thus, in nongregarious species, correct inferences of dispersal can only be achieved by combining several genetic approaches with detailed spatial information.

Anti-Mullerian hormone as a predictor of follicular reserve in ovarian insufficiency: special emphasis on FSH-resistant ovaries.

BACKGROUND: Anti-Müllerian hormone (AMH) is secreted by ovarian granulosa cells and its serum levels reflect ovarian follicle reserve. The main objective of this study was to test the use of AMH assay in identifying women with primary amenorrhea (PA) and existing follicles and to study follicle phase dependent AMH secretion. METHODS: Serum levels of AMH were measured in subjects with FSH-resistant ovaries (FSHRO, n= 12), primary ovarian insufficiency (POI) with PA (n= 11) or secondary amenorrhea (SA n= 20) of unknown etiology, and controls (n= 23), and in Turner syndrome (TS) [45,X (n= 18), mosaicism (n= 7), structural X chromosome abnormalities (SCA, n= 10)], and healthy controls (n= 34). RESULTS: Serum levels of AMH in women with FSHRO were comparable with those in control women (2.76 ± 2.37 versus 3.77 ± 2.36 ng/ml) and significantly higher than in women with PA (0.05 ± 0.04 ng/ml; P < 0.001) or SA of unknown origin (0.12 ± 0.20 ng/ml; P < 0.001). TS girls/women with 45,X or SCA had low serum AMH levels (0.13 ± 0.09 and 0.27 ± 0.19 ng/ml) compared with their controls (3.34 ± 2.23 ng/ml) or subjects with mosaicism (2.33 ± 2.81 ng/ml). AMH expression was detected in granulosa cells of women with FSHRO but not in any of the 45,X fetal ovarian specimens. CONCLUSIONS: A serum AMH assay could be used to identify patients with decreasing ovarian reserves and POI. Moreover, our results support the notion that AMH is secreted mainly by small non-selected follicles, since follicular granulosa cells were AMH-positive and serum AMH levels were normal/low normal in women with FSHRO, who lack follicle development beyond the small antral stage.

A comparison of different definitions of growth response in short prepubertal children treated with growth hormone.

BACKGROUND: How to define poor growth response in the management of short growth hormone (GH)-treated children is controversial. AIM: Assess various criteria of poor response. SUBJECTS AND METHODS: Short GH-treated prepubertal children [n = 456; height (Ht) SD score (SDS) ≤-2] with idiopathic GH deficiency (IGHD, n = 173), idiopathic short stature (ISS, n = 37), small for gestational age (SGA, n = 54), organic GHD (OGHD, n = 40), Turner syndrome (TS, n = 43), skeletal dysplasia (n = 15), other diseases (n = 46) or syndromes (n = 48) were evaluated in this retrospective multicenter study. Median age at GH start was 6.3 years and Ht SDS -3.2. RESULTS: Median [25-75 percentile] first-year gain in Ht SDS was 0.65 (0.40-0.90) and height velocity (HtV) 8.67 (7.51-9.90) cm/year. Almost 50% of IGHD children fulfilled at least one criterion for poor responders. In 28% of IGHD children, Ht SDS gain was <0.5 and they had lower increases in median IGF-I SDS than those with Ht SDS >0.5. Only IGHD patients with peak stimulated growth hormone level <3 µg/l responded better than those with ISS. A higher proportion of children with TS, skeletal dysplasia or born SGA had Ht SDS gain <0.5. CONCLUSION: Many children respond poorly to GH therapy. Recommendations defining a criterion may help in managing short stature patients.

Cognitive effects of aromatase inhibitor therapy in peripubertal boys.

OBJECTIVE: Aromatase inhibitors, blockers of oestrogen biosynthesis, have emerged as a new potential treatment modality for boys with short stature. The cognitive effects of such therapy are unknown. In this study, we explored the effects of aromatase inhibition on cognitive performance in peripubertal boys. DESIGN: Prospective, double-blind, randomised, placebo-controlled clinical study. METHODS: Twenty-eight boys, aged 9.0-14.5 years, with idiopathic short stature were treated with the aromatase inhibitor letrozole (2.5 mg/day) or placebo, for 2 years. During the treatment, the progression of physical signs of puberty and the concentrations of sex hormones were followed up. A selection of cognitive tests, focusing on memory function, was administered to the participants at entry, at 12 months and at 24 months after the start of the treatment. RESULTS: Letrozole effectively inhibited the conversion of androgen to oestrogen, as indicated by high serum testosterone and low serum oestradiol concentrations in letrozole-treated boys who progressed into puberty. In both the groups, there was a gain in performance during the follow-up period in tests of verbal performance, in most of the tests of visuospatial performance and in some tests of verbal memory. No significant differences between the letrozole- and placebo-treated boys in development of cognitive performance were found in any of the tests during the follow-up period. CONCLUSIONS: Our results suggest that blockade of oestrogen biosynthesis with an aromatase inhibitor does not influence cognitive performance in peripubertal males.

Differences in infantile growth patterns in Turner syndrome girls with and without spontaneous puberty.

OBJECTIVE: The role of prepubertal estrogen in child growth was modeled using Turner's syndrome, comparing growth patterns of girls who later did or did not enter puberty spontaneously. The hypothesis was that TS patients with normal prepubertal estrogen levels would have a different growth pattern from those with subnormal estrogen levels. STUDY DESIGN: Growth data from 78 full-term patients with Turner's syndrome were collected retrospectively. 24/78 later developed spontaneous puberty, (+Pub), and their growth data were compared to TS patients without spontaneous puberty (-Pub). A nonlinear mixed model was fitted using the bi-exponential model. RESULTS: The growth velocity difference between the -Pub and +Pub groups suggests an early infantile growth advantage in the -Pub group, which disappears before the end of the first year of life; growth velocity remains similar (+/- 1 cm/y) for the next 6 years and declines at age 7-8 years in the +Pub group faster than it does in the -Pub group. Bi-exponential analysis showed that both the 1st (restrictive) and 2nd exponent (forward) were different (p = 0.0003). CONCLUSIONS: Comparison of girls with or without spontaneous puberty suggests a role for estrogen in child growth. Estrogens restrict infantile growth, as well as growth during the mid-childhood spurt.

Subnormal androgen levels in young female bone marrow transplant recipients with ovarian dysfunction, chronic GVHD and receiving glucocorticoid therapy.

Ovarian function and sex hormone production with special focus on androgens (testosterone, androstenedione, dehydroepiandrosterone and its sulfate, DHEAS) was followed up during 1.5-20 (mean 9) years after bone marrow transplantation (BMT) in 24 female subjects aged 16-33 (mean 21) years at the last follow-up. All patients had received TBI and high-dose chemotherapy as the preparative regimen. A total of 24 female patients with conventionally treated pediatric hematologic malignancies served as controls. Four of 24 transplanted patients had spontaneous menstruation several years post transplantation, but in only one of them were serum FSH levels normal. Androgen levels of the BMT patients were lower than those of the conventionally treated patients. Subnormal testosterone levels were observed in 43% of BMT patients and subnormal DHEAS levels in 34% of BMT patients, the latter being a constant finding during glucocorticoid therapy for chronic GVHD (cGVHD). These results indicate that ovarian damage is a common late effect in patients transplanted at a young age, still having a seemingly normal pubertal development. Ovarian damage and cGVHD with glucocorticoid therapy are strongly associated with subnormal androgen levels. The clinical consequences of these changes and possible benefits of putative androgen replacement therapy remain to be elucidated.

Chemical anoxia delays germ cell apoptosis in the human testis.

An understanding of testicular physiology and pathology requires knowledge of the regulation of cell death. Previous observation of suppression of apoptosis by hypoxia suggested a role for ATP in germ cell death. However, the exact effects of ATP production on germ cell death and of apoptosis on the levels of ATP and other adenine nucleotides (ANs) have remained unclear. We investigated the levels of ANs during human testicular apoptosis (analyzed by HPLC) and the role of chemical anoxia in germ cell death (detected by Southern blot analysis of DNA fragmentation, in situ end labeling of DNA, and electron microscopy). Incubation of seminiferous tubule segments under serum-free conditions induced apoptosis and concomitantly decreased the levels of ANs. Chemical anoxia, induced with potassium cyanide (KCN), an inhibitor of mitochondrial respiration, dropped ATP levels further and suppressed apoptosis at 4 h. After 24 h, many of the testicular cells underwent delayed apoptosis despite ATP depletion. Some cells showed signs of necrosis or toxicity. The addition of 2-deoxyglucose, an antimetabolite of glycolysis, did not alter the results obtained with KCN alone, whereas a toxic concentration of hydrogen peroxide switched apoptosis to necrosis. In most of the testicular cells, mitochondrial respiration appears to play a crucial role in controlling primary cell death cascades. In the human testis, there seem to be secondary apoptotic pathways that do not require functional respiration (or ATP).

Restoration of ovarian function after chemotherapy for osteosarcoma.

AIM: To evaluate ovarian function after modern intensive multi-agent chemotherapy for osteosarcoma given during childhood or adolescence. METHODS: After discontinuation of treatment, 10 female osteosarcoma survivors were followed up for 1.5-14 (median 4.6) years. Their age at diagnosis was a median of 12.9 (range 6-15) years and at the last follow up 18.6 (range 16-22). The main follow up included recording of their pubertal and menstrual status and of sex hormone determinations. RESULTS: Prior to diagnosis, 5/10 had had their menarche, and one had it while on therapy. At discontinuation of chemotherapy, ovarian function had severely deteriorated; none of the girls experienced regular menstrual cycles. However, during follow up, significant restoration of ovarian function was evident. At the last follow up, 9/10 patients were menstruating spontaneously. During follow up, four patients, three of whom had received high doses of alkylating agents, presented with clear hypergonadotrophism with high FSH levels (14.4-132 IU/l). Three of these four patients initiated menstruation after their gonadotrophin levels normalised. CONCLUSIONS: The modern multi-agent chemotherapy applied for osteosarcoma impairs ovarian function. Normalisation of ovarian function is common, even in cases with severe hypergonadotrophic hypogonadism, but may only occur after several years off chemotherapy. Regular assessment of ovarian function and cautious use of hormone replacement therapy are important in patients with chemotherapy induced gonadal damage.

Cell death and its suppression in human ovarian tissue culture.

In women with premature ovarian failure, fertility may be preserved by ovarian tissue culture in vitro. However, techniques for tissue culture and follicle maturation have remained suboptimal. Our aim was to characterize ovarian tissue degeneration in cultures and to establish a model for cell death research in cultured ovarian tissue. Precise knowledge on the process resulting in cell death in cultured ovarian tissue will ultimately facilitate work aimed at improving long-term culture conditions. Ovarian tissue apoptosis was studied in a serum-free culture model in which nuclear DNA fragmentation was shown to occur within 24 h of the start of the culture. Activation of caspase-3 was detected in some stromal cells and a few oocytes. Since not all of the tissue exhibited signs of apoptosis and since DNA fragmentation increased over time, the tissue probably gradually dies by apoptosis. The antioxidant N-acetyl-L-cysteine (NAC; 25, 50 and 100 mmol/l) was found to inhibit this apoptosis. Thus, apoptosis appears to play a critical role in the degeneration of human ovarian cortical tissue cultures, and this cell death can be suppressed by NAC. The present tissue culture model can be used for identifying components capable of inhibiting cell death in vitro.

Lactate inhibits germ cell apoptosis in the human testis.

Dysregulation of male germ cell apoptosis has been associated with the pathogenesis of male infertility. Therefore, factors involved in the regulation of germ cell death are being actively investigated. Here, we studied the effects of lactate on human male germ cell death, using as a model a testis tissue culture in which physiological contacts are maintained between the germ cells and the supportive somatic Sertoli cells. Apoptosis of spermatocytes, spermatids and a few spermatogonia was induced by culturing segments of seminiferous tubules under serum-free conditions. This germ cell death was inhibited effectively and dose-dependently by lactate, indicating that it plays a crucial role in controlling cell death cascades of male germ cells. Interestingly, the anti-apoptotic role of lactate was not associated with changes in testicular adenine nucleotide (ATP, ADP and AMP) levels. In the seminiferous tubules, the final site of the death-suppressing action of lactate appeared to be downstream along the cell death pathway activated by the Fas receptor of the germ cells. In conclusion, testicular cell death was effectively regulated by lactate, which may be regarded as a potential compound for optimizing in-vitro methods involving male germ cells for assisted reproduction.

Inhibition of P450 aromatase enhances gonadotropin secretion in early and midpubertal boys: evidence for a pituitary site of action of endogenous E.

In early pubertal boys, E concentrations are very low. We studied the role and site of action of endogenous E in the regulation of gonadotropin secretion in early and midpubertal boys by inhibiting the action of E with a potent and specific P450 aromatase inhibitor, letrozole. A total of 35 boys who were referred to us because of suspicion of delayed puberty were included in the study. The boys were in either early or midpuberty, and they composed 3 groups: 10 boys did not receive any treatment, 12 boys received T alone, and 13 boys received T and letrozole. In the untreated group during the 5-month follow-up, no changes were observed in 17beta-E2, T, basal gonadotropin, or inhibin B concentrations or in the GnRH-induced gonadotropin responses. In the T-treated group during the 5-month treatment, the T concentration increased by 55% (P < 0.05), and the 17beta-E2 concentration increased by 130% (P < 0.02). Concurrently, basal gonadotropin concentrations were suppressed, but the GnRH-induced gonadotropin responses and the inhibin B concentration remained unchanged. In the T- plus letrozole-treated group during the 5-month treatment, an increase in T concentration of 606% was observed (P < 0.001), but the 17beta-E2 concentration remained unchanged. The changes in the 17beta-E2 concentration within 5 months in the untreated and the T- plus letrozole-treated groups were different (P < 0.02), indicating significant inhibition of endogenous E synthesis during letrozole treatment. During the T plus letrozole treatment, basal gonadotropin concentration, the GnRH-induced LH response, and inhibin B concentration increased, and the GnRH-induced FSH response did not change significantly. Serum nocturnal gonadotropin pulses were determined in 5 boys treated with T and in 5 boys treated with T plus letrozole. In the T- plus letrozole-treated group, the nocturnal LH pulse amplitude increased, and the LH pulse frequency and interpulse interval remained unchanged. In conclusion, in early and midpubertal boys, suppression of the action of E by the P450 aromatase inhibitor increased LH concentration, LH pulse amplitude, and the GnRH-induced LH response, which indicates that in boys during early and midpuberty, endogenous E regulates LH secretion at the site of the pituitary.

Markers of type I and III collagen turnover as indicators of growth velocity in very low birth weight infants.

Monitoring postnatal growth in very low birth weight (VLBW) infants is complicated by the difficulty of obtaining reliable measurements. A need thus exists for safe and reliable indicators of such infants' short-term growth velocity. We set out to study whether markers of type I collagen synthesis [amino-terminal propeptide of type I procollagen (PINP)] or degradation [via the matrix metalloproteinase pathway, carboxyl-terminal telopeptide of type I collagen (ICTP)] or of type III collagen synthesis [amino-terminal propeptide of type III procollagen (PIIINP)] could serve as such indicators. PINP, ICTP, and PIIINP were measured for 48 VLBW infants (mean birth weight, 923 g; range, 540-1485 g; mean gestational age, 27.6 wk; range, 23.7-32.7 wk) at the age of 1, 2, 4, and 8 wk. At each time point, these were compared with concurrent growth velocity rigorously assessed by frequent lower leg (knemometry) and weight measurements. PINP showed a significant positive correlation with lower leg growth velocity at 1, 2, and 4 wk and with weight growth velocity at 2, 4, and 8 wk. PIIINP showed a significant positive correlation with lower leg growth at 1, 2, and 8 wk and with weight growth at 2 and 8 wk. The ICTP/PINP ratio, reflecting type I collagen degradation in relation to its synthesis, showed close negative correlations with lower leg growth at 1 wk (r = -0.46; P = 0.003), 2 wk (r = -0.51; P = 0.002), and 4 wk (r = -0.56; P = 0.001) and with weight growth at 2 wk (r = -0.39; P = 0.018), 4 wk (r = -0.59; P = 0.0003), and 8 wk (r = -0.53; P = 0.005). A high ICTP/PINP ratio was an accurate predictor of impaired growth; a high ICTP/PINP ratio was a more rapid and at least as sensitive and specific indicator of slow growth as weight gain. We conclude that PINP, PIIINP, and the ICTP/PINP ratio all reflect postnatal growth velocity in VLBW infants. The most robust of these indicators is the ICTP/PINP ratio, which may thus serve as a clinical tool in assessing short-term growth of these infants.

TNFalpha down-regulates the Fas ligand and inhibits germ cell apoptosis in the human testis.

The cytokine TNFalpha is known to be secreted by testicular germ cells. However, its effect on maturing germ cells is unknown, and its role in the regulation of spermatogenesis is unclear. Here we aimed at characterizing the effects of TNFalpha on germ cell survival in the human testis. We found that TNFalpha effectively and dose-dependently inhibited germ cell apoptosis, which was induced in vitro by incubating segments of human seminiferous tubules under serum-free culture conditions. EMSAs indicated increased activity of nuclear factor kappaB in seminiferous tubules cultured under apoptosis-inducing conditions. However, we did not observe any significant effect of TNFalpha on the activation of this transcription factor, which is often considered to be a mediator of TNFalpha-induced survival signals. As the expression of the TNF receptor protein in the human seminiferous epithelium was predominantly found in the Sertoli cells, the antiapoptotic effect of TNFalpha is probably mediated via these somatic cells. Interestingly, expression of the Fas ligand, a known inductor of testicular apoptosis, was down-regulated by TNFalpha. Thus, in the seminiferous tubules, germ cell-derived TNFalpha may regulate the level of the Fas ligand and thereby control physiological germ cell apoptosis.

A specific aromatase inhibitor and potential increase in adult height in boys with delayed puberty: a randomised controlled trial.

BACKGROUND: The role of oestrogens in the closure of growth plates in both sexes is unequivocal. We postulated that inhibition of oestrogen synthesis in boys with delayed puberty would delay maturation of the growth plates and ultimately result in increased adult height. METHODS: We did a randomised, double-blind, placebo-controlled study in which we treated boys with constitutional delay of puberty with testosterone and placebo, or testosterone and letrozole. Boys who decided to wait for the spontaneous progression of puberty without medical intervention composed the untreated group. FINDINGS: Letrozole effectively inhibited oestrogen synthesis and delayed bone maturation. Progression of bone maturation was slower in the letrozole group than in the placebo group. In 18 months, bone age had advanced 1.1 (SD 0.8) years in the untreated group and 1.7 (0.9) years in the group treated with testosterone and placebo, but only 0.9 (0.6) years in the letrozole group (p=0.03 between the treatment groups). Predicted adult height did not change significantly in the untreated group and in the placebo group, whereas in the group treated with letrozole the increase was 5.1 (3.7) cm (p=0.004). INTERPRETATIONS: Our findings suggest that if oestrogen action is inhibited in growing adolescents, adult height will increase. This finding provides a rationale for studies that aim to delay bone maturation in several growth disorders.

Impaired spermatogenesis: an unrecognized feature of cartilage-hair hypoplasia.

BACKGROUND: Cartilage-hair hypoplasia (CHH), an autosomal recessive chondrodysplasia, is characterized by severe growth failure, hypoplastic hair, impaired immunity, and deficient erythropoiesis. These features may result from a generalized defect in cell proliferation. AIM: In order to investigate whether an impairment of cell proliferation is present in spermatogenesis, we analysed fertility in a clinical and laboratory study of adult males with CHH. METHODS: Eleven adult males (median age 29 years, range 21-49 years) with CHH were included in the study. The patients were examined clinically for testicular volume and other clinical characteristics. Blood samples were collected to determine serum concentrations of sex hormones, sex hormone-binding globulin, inhibin B and gonadotrophins (basal and gonadotrophin-releasing hormone-stimulated). Semen samples were analysed for volume, sperm concentration, motility, morphology, and antibody status. RESULTS: The testicular size was subnormal in some patients, but the serum concentrations of testosterone, inhibin B and gonadotrophins were usually normal. The semen analyses were not within normal limits in any of the patients, as indicated by low sperm concentration, decreased motility and/or morphological changes. CONCLUSIONS: The defect in cell proliferation in men with CHH also involves the spermatogenic cells and is evident as an impairment of spermatogenesis.

Novel assay for determination of androgen bioactivity in human serum.

We have developed a mammalian cell (COS-1) bioassay, which can measure androgen bioactivity directly from a small amount (10 microL) of human serum. The recombinant assay is based on androgen-dependent interaction between the ligand-binding domain and the N-terminal region of the androgen receptor (AR), which were fused to Gal4 DNA-binding domain of Saccharomyces cerevisiae and transcriptional activation domain of herpes simplex VP16 protein, respectively. The interaction is amplified by coexpression of AR-interacting protein 3 in the cells. The reporter plasmid contains 5 Gal4-binding sites upstream of the luciferase gene; luciferase activity in cell lysates is derived from androgen bioactivity in human serum. Saturating concentration of testosterone in FCS induced more than 700-fold induction in relative luciferase activity. The sensitivity was less than 1.0 nmol/L testosterone in FCS. The intra- and interassay coefficients of variation were 8.3% and 21%, respectively. Interaction between the AR termini was blocked by nonsteroidal antiandrogens, and the assay exhibited minimal cross-reactivity with 17 beta-estradiol. Serum androgen bioactivity was studied in 23 boys (13.9--16.8 yr old) with constitutional delay of puberty and in 9 prepubertal boys with cryptorchidism (1.0--6.4 yr old). Androgen bioactivity was detectable in 15 boys with constitutional delay of puberty and in all boys with cryptorchidism during treatment with human CG (range, 1.0-14.5 nmol/L testosterone equivalents). Serum androgen bioactivity measured by the bioassay correlated strongly with serum testosterone concentration (r = 0.93, P < 0.0001, n = 22) but not to 5 alpha-dihydrotestosterone, dehydroepiandrosterone, or androstenedione levels. We conclude that our novel bioassay enables quantitation of mammalian cell response to bioactive androgens in human serum, even in pediatric patients with relatively low androgen levels.

Treatment of delayed male puberty: efficacy of aromatase inhibition.

We hypothesized that inhibition of estrogen synthesis would delay maturation of the growth plates and ultimately result in increased adult height in boys with delayed puberty. We conducted a randomized, double-blind, placebo-controlled study in which we treated boys with constitutional delay of puberty with testosterone plus placebo (testosterone-placebo) or with testosterone plus letrozole (testosterone-letrozole). Letrozole effectively inhibited estrogen synthesis: 17beta-estradiol concentrations increased in the testosterone-placebo group, but in the testosterone-letrozole group, no such increase was observed until letrozole treatment was discontinued. After 1.5 years, bone age had advanced by 1.7 +/- 0.3 years in the testosterone-placebo group, but by only 0.9 +/- 0.2 years in the testosterone-letrozole group (p = 0.02). Predicted adult height did not change significantly in the testosterone-placebo group, whereas in the testosterone-letrozole group the increase was 5.1 +/- 1.2 cm (p = 0.004). Our findings suggest that, if estrogen action is inhibited in growing adolescents, adult height will increase. This observation provides a rationale for studies aimed at delaying bone maturation in several growth disorders.

Expression of transcription factor GATA-4 during human testicular development and disease.

GATA-4 is a highly conserved transcription factor that plays a critical role in regulating embryonic morphogenesis and cellular differentiation. Given the emerging role of GATA-4 in the development and function of murine gonads, we have now studied its role in human testis. We find that GATA-4 is expressed from early human fetal testicular development to adulthood. This transcription factor is evident in Sertoli cells through fetal and postnatal development. Expression of GATA-4 in Sertoli cells peaks at 19-22 weeks gestation at the time of high circulating fetal FSH. In Leydig cells, GATA-4 is expressed during fetal period and after puberty, coinciding with the periods of active androgen synthesis in the testis; this suggests a link between GATA-4 and steroidogenesis. Also, fetal germ cells and prepubertal spermatogonia express GATA-4, and it is down-regulated in these cells after puberty. As hormonal regulation of GATA-4 in human testis was not possible to study directly, we used testicular samples from patients who had endocrine abnormalities or were hormonally treated. Testicular expression of GATA-4 in hCG-treated cryptorchidism does not differ from that in controls. In androgen resistance, GATA-4 expression in Sertoli and germ cells is weak or totally absent. GATA-4 protein is abundantly present in Sertoli and Leydig cell tumors, suggesting a relationship to tumorigenesis or tumor progression in somatic cell-derived testicular neoplasms.