Long-Term Exposure to Neonicotinoid Insecticide Acetamiprid at Environmentally Relevant Concentrations Impairs Endocrine Functions in Zebrafish: Bioaccumulation, Feminization, and Transgenerational Effects.

Neonicotinoid insecticides have attracted worldwide attention due to their ubiquitous occurrence and detrimental effects on aquatic organisms, yet their impacts on fish reproduction during long-term exposure remain unknown. Here, zebrafish (F0) were exposed to a neonicotinoid, acetamiprid, at 0.19-1637 µg/L for 154 d. Accumulation and biotransformation of acetamiprid were observed in adult fish, and the parent compound and its metabolite (acetamiprid-N-desmethyl) were transferred to their offspring. Acetamiprid caused slight survival reduction and significant feminization in F0 fish even at the lowest concentration. Hormone levels in F0 fish were remarkedly altered, that is, gonad 17ß-estradiol (E2) significantly increased, while androstenedione decreased. The corresponding transcription of steroidogenic genes (ar, cyp19b, fshß, gnrh2, gnrh3, and lhß) were significantly upregulated in the brain and gonad of the females but downregulated in the males. The vtg1 gene expression in the liver of male fish was also upregulated. In addition to F0 fish, parental exposure to acetamiprid decreased hatchability and enhanced malformation of F1 embryos. Chronic exposure to acetamiprid at environmentally relevant concentrations altered hormone production and the related gene expression of the hypothalamic-pituitary-gonad (HPG) axis in a sex-dependent way, caused feminization and reproductive dysfunction in zebrafish, and impaired production and development of their offspring.

Transcriptome Analysis Reveals the Regulatory Networks of Cytokinin in Promoting Floral Feminization in Castanea henryi.

Castanea henryi is a monoecious plant with a low female-to-male ratio, which limits its yield. The phytohormone cytokinin (CK) plays a crucial role in flower development, especially gynoecium development. Here, the feminizing effect of CK on the development of C. henryi was confirmed by the exogenous spraying of N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU). Spraying CPPU at 125 mg·L-1 thrice changed the male catkin into a pure female catkin, whereas at 5 mg·L-1 and 25 mg·L-1, only a part of the male catkin was transformed into a female catkin. A comparative transcriptome analysis of male catkins subjected to CPPU was performed to study the mechanism of the role of CKs in sex differentiation. Using Pearson's correlation analysis between hormone content and hormone synthesis gene expression, four key genes, LOG1, LOG3, LOG7 and KO, were identified in the CK and GA synthesis pathways. Moreover, a hub gene in the crosstalk between JA and the other hormone signaling pathways, MYC2, was identified, and 15 flowering-related genes were significantly differentially expressed after CPPU treatment. These results suggest that CK interacts with other phytohormones to determine the sex of C. henryi, and CK may directly target floral organ recognition genes to control flower sex.

Castration delays epigenetic aging and feminizes DNA methylation at androgen-regulated loci.

In mammals, females generally live longer than males. Nevertheless, the mechanisms underpinning sex-dependent longevity are currently unclear. Epigenetic clocks are powerful biological biomarkers capable of precisely estimating chronological age and identifying novel factors influencing the aging rate using only DNA methylation data. In this study, we developed the first epigenetic clock for domesticated sheep (Ovis aries), which can predict chronological age with a median absolute error of 5.1 months. We have discovered that castrated male sheep have a decelerated aging rate compared to intact males, mediated at least in part by the removal of androgens. Furthermore, we identified several androgen-sensitive CpG dinucleotides that become progressively hypomethylated with age in intact males, but remain stable in castrated males and females. Comparable sex-specific methylation differences in MKLN1 also exist in bat skin and a range of mouse tissues that have high androgen receptor expression, indicating that it may drive androgen-dependent hypomethylation in divergent mammalian species. In characterizing these sites, we identify biologically plausible mechanisms explaining how androgens drive male-accelerated aging.

Gene Expression of Takifugu rubripes Gonads During AI- or MT-induced Masculinization and E2-induced Feminization.

Elucidating the global molecular changes that occur during aromatase inhibitor (AI)- or 17α-methyltestosterone (MT)-induced masculinization and estradiol-17ß (E2)-induced feminization is critical to understanding the roles that endocrine and genetic factors play in regulating the process of sex differentiation in fish. Here, fugu larvae were treated with AI (letrozole), MT, or E2 from 25 to 80 days after hatching (dah), and gonadal transcriptomic analysis at 80 dah was performed. The expression of dmrt1, gsdf, foxl2, and other key genes (star, hsd3b1, cyp11c1, cyp19a1a, etc.) involved in the steroid hormone biosynthesis pathway were found be altered. The expression of dmrt1, gsdf, cyp19a1a, and foxl2 was further verified by quantitative polymerase chain reaction. In the control group, the expression of dmrt1 and gsdf was significantly higher in XY larvae than in XX larvae, while the expression of foxl2 and cyp19a1a was significantly higher in XX larvae than in XY larvae (P < .05). AI treatment suppressed the expression of foxl2 and cyp19a1a, and induced the expression of dmrt1 and gsdf in XX larvae. MT treatment suppressed the expression of foxl2, cyp19a1a, dmrt1, and gsdf in XX larvae. E2 treatment suppressed the expression of dmrt1 and gsdf, but did not restore the expression of foxl2 and cyp19a1a in XY larvae. The shared response following AI, MT, and E2 treatment suggested that these genes are essential for sex differentiation. This finding offers some insight into AI or MT-induced masculinization, and E2-induced femininization in fugu.

Effects of adult male rat feminization treatments on brain morphology and metabolomic profile.

Body feminization, as part of gender affirmation process of transgender women, decreases the volume of their cortical and subcortical brain structures. In this work, we implement a rat model of adult male feminization which reproduces the results in the human brain and allows for the longitudinal investigation of the underlying structural and metabolic determinants in the brain of adult male rats undergoing feminization treatments. Structural MRI and Diffusion Tensor Imaging (DTI) were used to non-invasively monitor in vivo cortical brain volume and white matter microstructure over 30 days in adult male rats receiving estradiol (E2), estradiol plus cyproterone acetate (CA), an androgen receptor blocker and antigonadotropic agent (E2 + CA), or vehicle (control). Ex vivo cerebral metabolic profiles were assessed by 1H High Resolution Magic Angle Spinning NMR (1H HRMAS) at the end of the treatments in samples from brain regions dissected after focused microwave fixation (5 kW). We found that; a) Groups receiving E2 and E2 + CA showed a generalized bilateral decrease in cortical volume; b) the E2 + CA and, to a lesser extent, the E2 groups maintained fractional anisotropy values over the experiment while these values decreased in the control group; c) E2 treatment produced increases in the relative concentration of brain metabolites, including glutamate and glutamine and d) the glutamine relative concentration and fractional anisotropy were negatively correlated with total cortical volume. These results reveal, for the first time to our knowledge, that the volumetric decreases observed in trans women under cross-sex hormone treatment can be reproduced in a rat model. Estrogens are more potent drivers of brain changes in male rats than anti-androgen treatment.

The shutting down of the insulin pathway: a developmental window for Wolbachia load and feminization.

Using the isopod Armadillidium vulgare as a case study, we review the significance of the "bacterial dosage model", which connects the expression of the extended phenotype to the rise of the Wolbachia load. In isopods, the Insulin-like Androgenic Gland hormone (IAG) induces male differentiation: Wolbachia feminizes males through insulin resistance, presumably through defunct insulin receptors. This should prevent an autocrine development of the androgenic glands so that females differentiate instead: feminization should translate as IAG silencing and increased Wolbachia load in the same developmental window. In line with the autocrine model, uninfected males expressed IAG from the first larval stage on, long before the androgenic gland primordia begin to differentiate, and exponentially throughout development. In contrast in infected males, expression fully stopped at stage 4 (juvenile), when male differentiation begins. This co-occurred with the only significant rise in the Wolbachia load throughout the life-stages. Concurrently, the raw expression of the bacterial Secretion Systems co-increased, but they were not over-expressed relative to the number of bacteria. The isopod model leads to formulate the "bacterial dosage model" throughout extended phenotypes as the conjunction between bacterial load as the mode of action, timing of multiplication (pre/post-zygotic), and site of action (soma vs. germen).

A newly developed genetic sex marker and its application to understanding chemically induced feminisation in roach (Rutilus rutilus).

Oestrogenic wastewater treatment works (WwTW) effluents discharged into UK rivers have been shown to affect sexual development, including inducing intersex, in wild roach (Rutilus rutilus). This can result in a reduced breeding capability with potential population level impacts. In the absence of a sex probe for roach it has not been possible to confirm whether intersex fish in the wild arise from genetic males or females, or whether sex reversal occurs in the wild, as this condition can be induced experimentally in controlled exposures to WwTW effluents and a steroidal oestrogen. Using restriction site-associated DNA sequencing (RAD-seq), we identified a candidate for a genetic sex marker and validated this marker as a sex probe through PCR analyses of samples from wild roach populations from nonpolluted rivers. We also applied the sex marker to samples from roach exposed experimentally to oestrogen and oestrogenic effluents to confirm suspected phenotypic sex reversal from males to females in some treatments, and also that sex-reversed males are able to breed as females. We then show, unequivocally, that intersex in wild roach populations results from feminisation of males, but find no strong evidence for complete sex reversal in wild roach at river sites contaminated with oestrogens. The discovered marker has utility for studies in roach on chemical effects, wild stock assessments, and reducing the number of fish used where only one sex is required for experimentation. Furthermore, we show that the marker can be applied nondestructively using a fin clip or skin swab, with animal welfare benefits.

Feminizing effects of exposure to Corexit-enhanced water-accommodated fraction of crude oil in vitro on sex determination in Alligator mississippiensis.

Deepwater Horizon spilled over 200 million gallons of oil into the waters of the Gulf of Mexico in 2010. In an effort to contain the spill, chemical dispersants were applied to minimize the amount of oil reaching coastal shorelines. However, the biological impacts of chemically-dispersed oil are not well characterized, and there is a particular lack of knowledge concerning sublethal long-term effects of exposure. This study examined potential estrogenic effects of CWAF, Corexit 9500-enhanced water-accommodated fraction of oil, by examining its effect on estrogen receptors and sex determination in the American alligator, Alligator mississippiensis. The alligator exhibits temperature-dependent sex determination which is modulated by estrogen signals, and exposure to 17ß-estradiol (E2) and estrogenic compounds in ovo during the thermosensitive period of embryonic development can induce ovarian development at a male-producing temperature (MPT). CWAF induced transactivation up to 50% of the maximum induction by E2 via alligator estrogen receptors in vitro. To determine potential endocrine-disrupting effects of exposure directly on the gonad, gonad-adrenal-mesonephric (GAM) organ complexes were isolated from embryos one day prior to the thermosensitive period and exposed to E2, CWAF, or medium alone in vitro for 8-16 days at MPT. Both CWAF and E2 exposure induced a significant increase in female ratios. CWAF exposure suppressed GAM mRNA abundances of anti-Müllerian hormone (AMH), sex determining region Y-box 9, and aromatase, whereas E2 exposure suppressed AMH and increased Forkhead box protein L2 mRNA abundances in GAM. These results indicate that the observed endocrine-disrupting effects of CWAF are not solely estrogenically mediated, and further investigations are required.

Serotonin promotes feminization of the sexually dimorphic nucleus of the preoptic area, but not the calbindin cell group.

Testosterone and its metabolites masculinize the brain during a critical perinatal window, including the relative volume of sexually dimorphic brain areas such as the sexually dimorphic nucleus of the preoptic area (SDN), which is larger in males than females. Serotonin (5HT) may mediate this hormone action, since 5HT given during the second week of life decreases (i.e., feminizes) SDN volume in males and testosterone-treated females. Although previous work indicates that the 5HT2A/2C receptor is sufficient to induce feminization, it is unclear whether other serotonin receptors are required and which subpopulation(s) of SDN cells are specifically organized by 5HT. Therefore, we injected male and female Sprague-Dawley rat pups with saline, a nonselective 5HTR agonist, a 5HT2A/2C agonist, or a 5HT2A/2C antagonist over several timecourses in early life, and measured the Nissl-SDN as well as a calbindin+ subdivision of the SDN, the CALB-SDN. When examined on postnatal day 18 or early adulthood, the size of the Nissl-SDN was feminized in males treated with any of the serotonergic drugs, eliminating the typical sex difference. In contrast, the sex difference in CALB-SDN size was maintained regardless of serotoninergic drug treatment. This pattern suggests that although gonadal hormones shape the whole SDN, individual cellular phenotypes respond to different intermediary signals to become sexually dimorphic. Specifically, 5HT mediates sexual differentiation of non-calbindin population(s) within the SDN. The results also caution against using measurement of the CALB-SDN in isolation, as the absence of an effect on the CALB-SDN does not preclude an effect on the overall nucleus. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1241-1253, 2016.

Transgenic Chickens Overexpressing Aromatase Have High Estrogen Levels but Maintain a Predominantly Male Phenotype.

Estrogens play a key role in sexual differentiation of both the gonads and external traits in birds. The production of estrogen occurs via a well-characterized steroidogenic pathway, which is a multistep process involving several enzymes, including cytochrome P450 aromatase. In chicken embryos, the aromatase gene (CYP19A1) is expressed female-specifically from the time of gonadal sex differentiation. Ectopic overexpression of aromatase in male chicken embryos induces gonadal sex reversal, and male embryos treated with estradiol become feminized; however, this is not permanent. To test whether a continuous supply of estrogen in adult chickens could induce stable male to female sex reversal, 2 transgenic male chickens overexpressing aromatase were generated using the Tol2/transposase system. These birds had robust ectopic aromatase expression, which resulted in the production of high serum levels of estradiol. Transgenic males had female-like wattle and comb growth and feathering, but they retained male weights, displayed leg spurs, and developed testes. Despite the small sample size, this data strongly suggests that high levels of circulating estrogen are insufficient to maintain a female gonadal phenotype in adult birds. Previous observations of gynandromorph birds and embryos with mixed sex chimeric gonads have highlighted the role of cell autonomous sex identity in chickens. This might imply that in the study described here, direct genetic effects of the male chromosomes largely prevailed over the hormonal profile of the aromatase transgenic birds. This data therefore support the emerging view of at least partial cell autonomous sex development in birds. However, a larger study will confirm this intriguing observation.

Reversibility of endocrine disruption in zebrafish (Danio rerio) after discontinued exposure to the estrogen 17α-ethinylestradiol.

The aim of the present study was to investigate the persistence of the feminizing effects of discontinued 17α-ethinylestradiol (EE2) exposure on zebrafish (Danio rerio). An exposure scenario covering the sensitive phase of sexual differentiation, as well as final gonad maturation was chosen to examine the estrogenic effects on sexual development of zebrafish. Two exposure scenarios were compared: continuous exposure to environmentally relevant concentrations (0.1-10 ng/L EE2) up to 100 days post-hatch (dph) and developmental exposure up to 60 dph, followed by 40 days of depuration in clean water. The persistence of effects was investigated at different biological organization levels from mRNA to population-relevant endpoints to cover a broad range of important parameters. EE2 had a strong feminizing and inhibiting effect on the sexual development of zebrafish. Brain aromatase (cyp19b) mRNA expression showed no clear response, but vitellogenin levels were significantly elevated, gonad maturation and body growth were inhibited in both genders, and sex ratios were skewed towards females and undifferentiated individuals. To a large extent, all of these effects were reversed after 40 days of recovery, leading to the conclusion that exposure to the estrogen EE2 results in very strong, but reversible underdevelopment and feminization of zebrafish. The present study is the first to show this reversibility at different levels of organization, which gives better insight into the mechanistic basis of estrogenic effects in zebrafish.

Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice.

Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver.

Androgen receptor promotes sex-independent angiogenesis in response to ischemia and is required for activation of vascular endothelial growth factor receptor signaling.

BACKGROUND: Hypoandrogenemia is associated with an increased risk of ischemic diseases. Because actions of androgens are exerted through androgen receptor (AR) activation, we studied hind-limb ischemia in AR knockout mice to elucidate the role of AR in response to ischemia. METHODS AND RESULTS: Both male and female AR knockout mice exhibited impaired blood flow recovery, more cellular apoptosis, and a higher incidence of autoamputation after ischemia. In ex vivo and in vivo angiogenesis studies, AR-deficient vascular endothelial cells showed reduced angiogenic capability. In ischemic limbs of AR knockout mice, reductions in the phosphorylation of the Akt protein kinase and endothelial nitric oxide synthase were observed despite a robust increase in hypoxia-inducible factor 1α and vascular endothelial cell growth factor (VEGF) gene expression. In in vitro studies, siRNA-mediated ablation of AR in vascular endothelial cells blunted VEGF-stimulated phosphorylation of Akt and endothelial nitric oxide synthase. Immunoprecipitation experiments documented an association between AR and kinase insert domain protein receptor that promoted the recruitment of downstream signaling components. CONCLUSIONS: These results document a physiological role of AR in sex-independent angiogenic potency and provide evidence of novel cross-talk between the androgen/AR signaling and VEGF/kinase insert domain protein receptor signaling pathways.

Feminizing adrenocortical carcinoma with selective suppression of follicle-stimulating hormone secretion and disorganized steroidogenesis: a case report and literature review.

We report a 61-year-old male with gynecomastia, poor libido and erectile dysfunction. Endocrinological studies showed high levels of estradiol and dehydroepiandrosterone sulfate. Although luteinizing hormone (LH) level was within the normal limit, the concentration of follicle-stimulating hormone (FSH) was under the normal limit. Delayed response of LH and poor response of FSH to gonadotropin-releasing hormone administration were detected. Magnetic resonance imaging of the abdomen revealed a left adrenal tumor. Although the surgically-resected tumor was diagnosed as a high grade ACC based on Weiss's criteria of adrenocortical malignancy, no metastasis was detected. Since estrogen levels normalized after resection, feminizing ACC was confirmed. While LH concentration increased slightly after operation, FSH level became transiently elevated over the normal limit, and finally reached the normal range. These data may suggest that FSH was suppressed selectively by hormone produced by ACC different from estrogen.

Genetic feminization of the thoracic nervous system disrupts courtship song in male Drosophila melanogaster.

Despite the growing research investigating the sex-specific organization of courtship behavior in Drosophila melanogaster, much remains to be understood about the sex-specific organization of the motor circuit that drives this behavior. To investigate the sex-specification of a tightly patterned component of courtship behavior, courtship song, the authors used the GAL4/UAS targeted gene expression system to feminize the ventral ganglia in male Drosophila and analyzed the acoustic properties of courtship song. More specifically, the authors used the thoracic-specifying teashirt promoter (tsh(GAL4)) to express feminizing transgenes specifically in the ventral ganglia. When tsh(GAL4) drove expression of transformer (tra), males were unable to produce prolonged wing extensions. Transgenic expression of an RNAi construct directed against male-specific fruitless (fru(M)) transcripts resulted in normal wing extension, but highly defective courtship song, with 58% of males failing to generate detectable courtship song. Of those that did sing, widths of individual pulses were significantly broader than controls, suggesting thoracic fru(M) function serves to mediate proprioceptive-dependent wing vibration damping during pulse song. However, the most critical signal in the song, the interpulse interval, remained intact. The inability to phenocopy this effect by reducing fru(M) expression in motor neurons and proprioceptive neurons suggests thoracic interneurons require fru(M) for proper pulse song execution and patterning of pulse structure, but not for pulse timing. This provides evidence that genes establishing sex-specific activation of complex behaviors may also be used in establishing pattern-generating motor networks underlying these sex-specific behaviors.

Prevalence of low bone mass in relation to estrogen treatment and body composition in male-to-female transsexual persons.

Bone health is a parameter of interest in the daily follow-up of male-to-female (M --> F) transsexual persons both before and after sex reassignment surgery (SRS) due to an intensely changing hormonal milieu. We have studied body composition, areal, geometric, and volumetric bone parameters, using DXA and peripheral quantitative computed tomography at different sites in 50 M --> F transsexual persons, at least 3 yr after the start of the hormonal treatment and 1 yr after SRS. In this cross-sectional study, hormone levels and markers of bone metabolism were assessed using immunoassays. Prevalence of low bone mass as defined by a Z-score < or = -2.0 according to DXA criteria was 26% at lumbar spine and 2% at the total hip. We found no major differences in hormonal parameters between participants with a Z-score < or = or > -2.0. Markers of bone turnover were comparable between subjects with or without low bone mass, indicating a stable bone turnover at the time of investigation. No significant differences in bone size or density were observed between patients on transdermal vs. oral estrogens. Low bone mass is not uncommon in M --> F transsexual persons. Smaller bone size, and a strikingly lower muscle mass compared with men appear to underlie these findings.

Expression analysis of sex-specific and 17beta-estradiol-responsive genes in the Japanese medaka, Oryzias latipes, using oligonucleotide microarrays.

Gene profiling of Japanese medaka (Oryzias latipes) was performed using an oligonucleotide DNA microarray representing 22,587 TIGR O. latipes gene indices (OLGIs). The average correlation coefficients for gene expression between individual mature fish were high (>0.95) for both female and male, indicating that the physiological status of medaka is highly reproducible under prescribed growth conditions. Of the 22,587 OLGIs, 2575 showed significant differences in expression between female and male. Exposure to 17beta-estradiol (E2) revealed 381 E2-responsive OLGIs in male medaka. Feminization and male-dysfunction factors of the E2-treated males calculated using the combination of Pearson correlation coefficient and Euclidean distances indicate that E2 treatment "weakly feminized" male medaka, while male physiological functions were not significantly disrupted. This study demonstrates the possibility of using medaka microarrays to estimate the overall effects of hormonally active chemicals.

Remote sensing of intraperitoneal parasitism by the host's brain: regional changes of c-fos gene expression in the brain of feminized cysticercotic male mice.

Experimental intraperitoneal Taenia crassiceps cysticercosis in mice exhibits distinct genetical, immunological and endocrinological features possibly resulting from the complex interactive network of their physiological systems. Very notable is the tendency of parasites to grow faster in hosts of the female sex. It is also remarkable in the feminization process that the infection induces in chronically infected male mice, characterized by their estrogenization, deandrogenization and loss of sexual and aggressive patterns of behaviour. The proto-oncogene c-fos is a sex steroid-regulated transcription factor gene, expressed basally and upon stimulation by many organisms. In the CNS of rodents, c-fos is found expressed in association to sexual stimulation and to various immunological and stressful events. Hence, we suspected that changes in c-fos expression in the brain could be involved in the feminization of the infected male mice. Indeed, it was found that c-fos expression increased at different times during infection in the hypothalamus, hippocampus, less so in the preoptic area and cortex, and not in several other organs. The significant and distinctive regional changes of c-fos in the CNS of infected mice indicate that the brain of the host senses intraperitoneal cysticercosis and may also announce its active participation in the regulation of the host-parasite relationship. Possibly, the host's CNS activity is involved in the network that regulates the estrogenization and deandrogenization observed in the chronically infected male mice, as well as in the behavioural and immunological peculiarities observed in this parasitic infection.

The presence of morphologically intermediate papilla syndrome in United Kingdom populations of sand goby (Pomatoschistus spp): endocrine disruption?

The sand goby (Pomatoschistus spp.) is a small estuarine fish. Its abundance, life history, and sedentary nature lead to its adoption as a key species in the U.K. Endocrine Disruption in the Marine Environment (EDMAR) Program. This study investigated the presence of classic markers of estrogenic exposure by determining vitellogenin (VTG) and zona radiata protein (ZRP) mRNA levels and ovotestis in estuarine-caught male gobies and investigated morphological changes in the urogenital papilla (UGP). Laboratory exposures to estrogens were also conducted to ascertain the responses of these markers. Wild-caught male fish showed no evidence of ovotestis, VTG, or ZRP mRNA induction. Laboratory exposures suggested that sensitivity of the goby to VTG/ ZRP mRNA induction was similar to flounder. The UGP inspection of wild-caught specimens revealed evidence of feminization of male papillae, a condition denoted as morphologically intermediate papilla syndrome (MIPS). Morphologically intermediate papilla syndrome was more prevalent at estrogenically contaminated sites. Juvenile goby experimentally exposed to 17beta-estradiol for 11 to 32 weeks exhibited signs of the MIPS condition, showing that it was inducible by estrogenic exposure and could therefore be a form of estrogenic endocrine disruption. The estuaries where the MIPS condition was most prevalent (>50% at certain sites) were the Tees, Mersey, and Clyde. The potential of the MIPS condition to significantly interfere with reproductive performance is discussed as well as its use as a monitoring tool for endocrine disruption in the estuarine environment.

Steroid deficiency syndromes in mice with targeted disruption of Cyp11a1.

Steroid deficiencies are diseases affecting salt levels, sugar levels, and sexual differentiation. To study steroid deficiency in more detail, we used a gene-targeting technique to insert a neo gene into the first exon to disrupt Cyp11a1, the first gene in steroid biosynthetic pathways. Cyp11a1 null mice do not synthesize steroids. They die shortly after birth, but can be rescued by steroid injection. Due to the lack of feedback inhibition by glucocorticoid, their circulating ACTH levels are exceedingly high; this results in ectopic Cyp21 gene expression in the testis. Male Cyp11a1 null mice are feminized with female external genitalia and underdeveloped male accessory sex organs. Their testis, epididymis, and vas deferens are present, but undersized. In addition, their adrenals and gonads accumulate excessive amounts of lipid. The lack of steroid production, abnormal gene expression, and aberrant reproductive organ development resemble various steroid deficiency syndromes, making these mice good models for studies of steroid function and regulation.