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Relationship: 3705

Title

A descriptive phrase which clearly defines the two KEs being considered and the sequential relationship between them (i.e., which is upstream, and which is downstream). More help

Antagonism, Androgen receptor leads to AR transcriptional activity in GT tissues, reduced

Upstream event
The causing Key Event (KE) in a Key Event Relationship (KER). More help
Downstream event
The responding Key Event (KE) in a Key Event Relationship (KER). More help

Key Event Relationship Overview

The utility of AOPs for regulatory application is defined, to a large extent, by the confidence and precision with which they facilitate extrapolation of data measured at low levels of biological organisation to predicted outcomes at higher levels of organisation and the extent to which they can link biological effect measurements to their specific causes.Within the AOP framework, the predictive relationships that facilitate extrapolation are represented by the KERs. Consequently, the overall WoE for an AOP is a reflection in part, of the level of confidence in the underlying series of KERs it encompasses. Therefore, describing the KERs in an AOP involves assembling and organising the types of information and evidence that defines the scientific basis for inferring the probable change in, or state of, a downstream KE from the known or measured state of an upstream KE. More help

AOPs Referencing Relationship

AOP Name Adjacency Weight of Evidence Quantitative Understanding Point of Contact Author Status OECD Status
Androgen receptor antagonism leads to delayed preputial seperation via reduced fibroblast growth factor in genital-tubercle tissues adjacent Travis Karschnik (send email) Under development: Not open for comment. Do not cite

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KER.In general, this will be dictated by the more restrictive of the two KEs being linked together by the KER.  More help
Term Scientific Term Evidence Link
Mus musculus Mus musculus High NCBI
Rattus norvegicus Rattus norvegicus High NCBI
Homo sapiens Homo sapiens High NCBI
mammals mammals High NCBI

Sex Applicability

An indication of the the relevant sex for this KER. More help
Sex Evidence
Male High
Female Low

Life Stage Applicability

An indication of the the relevant life stage(s) for this KER.  More help
Term Evidence
Development Moderate
Fetal to Parturition High
Foetal High
Embryo High

Key Event Relationship Description

Provides a concise overview of the information given below as well as addressing details that aren’t inherent in the description of the KEs themselves. More help

The androgen receptor (AR) is a ligand-activated nuclear transcription factor belonging to the nuclear receptor superfamily. Under normal developmental conditions, androgens (principally testosterone and its more potent metabolite dihydrotestosterone, DHT) bind to the AR in target tissues, triggering a conformational change, dissociation from heat shock proteins, receptor dimerization, nuclear translocation, and binding to androgen response elements (AREs) in the promoter regions of androgen-responsive genes (Brinkmann et al., 1999; Heinlein & Chang, 2002). This sequence of events constitutes AR-mediated transcriptional activation.

In the genital tubercle, AR-dependent transcription contributes to a program of gene expression necessary for androgen-dependent GT outgrowth and masculinization during fetal development. The GT is the embryological precursor of the penis (and glans clitoris in females), and its masculinization depends in part on sustained AR signaling during a defined developmental window (Welsh et al., 2008; Blaschko et al., 2012). Downstream targets of AR-mediated transcription in the GT include components of the FGF signaling pathway (Petiot et al. 2005).

AR antagonism, whether by exogenous antiandrogens (e.g., flutamide, vinclozolin, procymidone, finasteride-class compounds active via AR) or endocrine disrupting chemicals with antiandrogenic activity, competitively occupies the ligand-binding domain (LBD) of the AR without inducing the transcriptionally competent conformation. The antagonist-bound AR fails to productively recruit coactivators and fails to drive ARE-dependent transcription. The consequence in GT tissue is a reduction in the transcriptional output that normally promotes GT growth, mesenchymal-epithelial signaling, and patterning gene expression.

Persistent AR antagonism during the critical developmental window in the GT is therefore causally linked to a reduction in AR transcriptional activity in GT mesenchymal and epithelial cells, which in turn compromises the androgen-driven gene expression program required for normal masculinization.

Evidence Collection Strategy

Include a description of the approach for identification and assembly of the evidence base for the KER. For evidence identification, include, for example, a description of the sources and dates of information consulted including expert knowledge, databases searched and associated search terms/strings.  Include also a description of study screening criteria and methodology, study quality assessment considerations, the data extraction strategy and links to any repositories/databases of relevant references.Tabular summaries and links to relevant supporting documentation are encouraged, wherever possible. More help

Evidence for this KER was assembled through a combination of expert knowledge and AI-assisted literature search and synthesis. Specifically, a combination of Claude (Anthropic) using Sonnet 4.6, and EPA AI, using GPT5, was used to identify, retrieve, and summarize relevant primary and secondary literature, and to draft the initial content of this KER page. All citations generated through this process were subsequently reviewed and verified by the KER author against primary sources and DOI resolution checks, prior to inclusion. Users of this KER are advised that AI-assisted evidence assembly may introduce selection bias or gaps in coverage that differ from a fully systematic human-conducted review, and independent verification of the evidence base is encouraged.  A copy of the initial prompt is attached to AOP619.

A review of primary experimental literature using the following databases and search strategies was employed:

PubMed/MEDLINE searches were conducted (literature through early 2025) using the following terms and combinations: "androgen receptor antagonism genital tubercle," "AR transcriptional activity fetal genitalia," "antiandrogen hypospadias," "flutamide androgen response element," "DHT transcription GT," "vinclozolin androgen receptor," "AR coactivator recruitment antiandrogen," "androgen responsive genes penis development," and "dihydrotestosterone genital tubercle gene expression."

Additional sources consulted include: OECD Test Guideline documentation (TG 421, TG 422, TG 441, and the Hershberger assay TG 441); U.S. EPA EDSP (Endocrine Disruptor Screening Program) documentation; and review articles on male reproductive development and AR biology.

Screening criteria prioritized studies that directly measured AR transcriptional readouts (ARE-reporter activity, androgen-responsive gene mRNA/protein levels) in GT tissue or GT-relevant cell lines in the context of AR ligand antagonism, or that linked AR antagonism to altered GT gene expression during the male programming window.

Evidence Supporting this KER

Addresses the scientific evidence supporting KERs in an AOP setting the stage for overall assessment of the AOP. More help

The quantitative relationship between the degree of AR antagonism and the magnitude of reduction in AR transcriptional activity in GT tissues is biologically grounded in competitive receptor pharmacology but is incompletely characterized with GT-tissue-specific empirical data. The available evidence is summarized below by subsection.

Biological Plausibility
Addresses the biological rationale for a connection between KEupstream and KEdownstream.  This field can also incorporate additional mechanistic details that help inform the relationship between KEs, this is useful when it is not practical/pragmatic to represent these details as separate KEs due to the difficulty or relative infrequency with which it is likely to be measured.   More help

The biological rationale for this KER is grounded in the canonical mechanism of nuclear receptor pharmacology and developmental androgen biology.

The AR ligand-binding domain (LBD) accommodates either agonist ligands (testosterone, DHT) or antagonist ligands (e.g., flutamide, bicalutamide, vinclozolin metabolites, hydroxyflutamide). Agonist binding induces Helix-12 repositioning within the LBD, creating a surface that recruits p160 coactivators (SRC-1, SRC-2/GRIP1, SRC-3) via their LXXLL motifs; this coactivator complex recruits general transcription machinery and histone acetyltransferases, ultimately enabling transcription of androgen-responsive genes (Heinlein & Chang, 2002). Chromatin immunoprecipitation studies confirm that agonist-bound AR recruits coactivators and RNA polymerase II to androgen response elements at target gene enhancers and promoters, whereas antagonist-bound AR instead recruits corepressors to the promoter (Shang et al., 2002). In contrast, antagonist binding can prevent productive AR transcriptional activation. Structural studies of bicalutamide bound to a mutant AR LBD provide evidence that antagonist binding makes direct contacts with Helix-12 residues in a manner that would disrupt the AF-2 coactivator-binding groove, preventing productive coactivator surface formation, as seen in a mutant complex (Bohl et al., 2005). Masiello et al., 2002 showed that bicalutamide-liganded AR translocates to the nucleus and binds DNA but fails to stimulate AR N/C-terminal interaction or recruit SRC-1 or SRC-2 coactivator proteins, resulting in a transcriptionally inactive receptor complex on DNA.

In the GT specifically, AR is expressed in mesenchymal cells of the developing phallus from early embryonic stages, particularly in the bilateral mesenchyme flanking the urethral plate from approximately E14.5 in mice (Miyagawa et al., 2009; Matsushita et al., 2018; Blaschko et al., 2012). Downstream androgen-responsive genes in the GT include those governing cell proliferation, apoptosis suppression, and mesenchymal-epithelial inductive signaling (e.g., Fgf10, Bmp4, Wnt5a regulation downstream of androgen signaling; Seifert et al., 2008).

The direct mechanistic chain from AR occupancy by an antagonist to failure of ARE-driven transcriptional activation in GT mesenchyme is therefore strongly supported by the combined understanding of AR structural biology and GT developmental biology.

Uncertainties and Inconsistencies
Addresses inconsistencies or uncertainties in the relationship including the identification of experimental details that may explain apparent deviations from the expected patterns of concordance. More help

Several uncertainties and gaps should be noted:

  1. Direct measurement of AR transcriptional activity specifically within GT mesenchymal cells in intact fetal tissue, following pharmacological AR antagonism at defined doses, is technically challenging. Most in vivo evidence relies on surrogate endpoints (AGD, GT morphology, anogenital index) or on measurement of downstream gene expression rather than a direct ARE-reporter readout within GT tissue. Transcriptomic profiling of GT tissue from antiandrogen-treated fetuses is limited in the literature, representing a data gap.
  2. The distinction between AR antagonism as the sole mechanism and combined effects on androgen biosynthesis (e.g., some phthalates reduce testosterone production as a primary mechanism, with AR antagonism being secondary or absent) can complicate attribution of reduced GT transcriptional activity specifically to AR antagonism versus ligand depletion.
  3. Species differences in AR LBD amino acid sequence may affect binding affinity of specific antiandrogens, introducing uncertainty in cross-species extrapolation of specific chemical potencies, even though the overall mechanism is conserved.
  4. AR coregulator expression profiles in GT mesenchyme during the critical window are not fully characterized; variation in coregulator availability could modulate the transcriptional response to a given degree of AR occupancy by antagonist, representing a potential source of inter-individual or inter-strain variability.

Known modulating factors

This table captures specific information on the MF, its properties, how it affects the KER and respective references.1.) What is the modulating factor? Name the factor for which solid evidence exists that it influences this KER. Examples: age, sex, genotype, diet 2.) Details of this modulating factor. Specify which features of this MF are relevant for this KER. Examples: a specific age range or a specific biological age (defined by...); a specific gene mutation or variant, a specific nutrient (deficit or surplus); a sex-specific homone; a certain threshold value (e.g. serum levels of a chemical above...) 3.) Description of how this modulating factor affects this KER. Describe the provable modification of the KER (also quantitatively, if known). Examples: increase or decrease of the magnitude of effect (by a factor of...); change of the time-course of the effect (onset delay by...); alteration of the probability of the effect; increase or decrease of the sensitivity of the downstream effect (by a factor of...) 4.) Provision of supporting scientific evidence for an effect of this MF on this KER. Give a list of references.  More help
Modulating Factor (MF) MF Specification Effect(s) on the KER Reference(s)
5-alpha-reductase 2 (SRD5A2) activity SRD5A2 converts testosterone to DHT in GT mesenchyme Higher SRD5A2 activity increases local DHT, requiring higher antagonist concentration to achieve equivalent AR occupancy and transcriptional suppression; SRD5A2 deficiency reduces DHT and sensitizes AR to inhibition at lower androgen-to-antagonist ratios Deslypere et al. (1992); Kim et al. (2002); Blaschko et al. (2012)
Gestational timing of exposure The male programming window (MPW) in rats is approximately E15.5 to E18.5; earlier or later exposure has reduced impact on GT transcriptional response as qualified by phenotypic and protein level evidence Antiandrogen timing, whether during windows of increased or decreased AR-responsiveness  have consequences for GT gene expression Welsh et al. (2008); van den Driesche et al. (2012); Seifert et al. (2012)
Dose/concentration of antagonist Competitive antagonism is dose-dependent; the magnitude of AR transcriptional suppression depends on the ratio of antagonist to agonist concentrations at the receptor Higher antagonist-to-androgen ratios produce greater suppression of AR transcriptional activity; at subthreshold doses effects may be absent or minimal Kelce et al. (1997); Gray et al. (2022); Rider et al. (2009)
AR coactivator availability Higher coactivator availability generally increases AR transcriptional output; lower availability decreases it. This can be assessed by coactivator expression or recruitment measures. Effects are cell‑ and promoter‑context dependent. Coactivator abundance modulates the magnitude of transcriptional decrease elicited by AR antagonists. Higher coactivator levels can, in some contexts, permit greater residual AR-driven transcription in the presence of antagonists, whereas lower levels tend to enhance suppression Shang et al. (2002); Heinlein & Chang (2002)
Combined/mixture antiandrogen exposure Co‑exposure to multiple chemicals that reduce androgen signaling produces cumulative (approximately additive) suppression of androgen‑dependent endpoints  Mixture exposures can suppress AR transcription at individual chemical concentrations that would be sub-effective alone Rider et al. (2009)
Species / AR sequence variation Differences in AR amino‑acid sequence, especially within the ligand‑binding domain LBD, can alter ligand binding and efficacy for specific antagonists. Species/AR sequence variation modulates the magnitude of the decrease in AR‑dependent transcription elicited by AR antagonists at a given exposure. For a given ligand, lower AR affinity in one species (or variant) can attenuate suppression; higher affinity can amplify it. Kelce et al. (1997); Bohl et al. (2005); Hosokawa et al. (1993)
Response-response Relationship
Provides sources of data that define the response-response relationships between the KEs.  More help
Time-scale
Information regarding the approximate time-scale of the changes in KEdownstream relative to changes in KEupstream (i.e., do effects on KEdownstream lag those on KEupstream by seconds, minutes, hours, or days?). More help

Cell models (hours scale): In HepARE-Luc cells, agonist-driven AR reporter activity begins to rise by ~6 h and is routinely quantified at 24 h; flutamide co-exposure reduces DHT-driven transcription over this 24 h window (e.g., ~50% at 1 μM; ~85% at 5 μM with 0.3 nM DHT) (Agrawal et al., 2022). Likewise, the AR-CALUX assay defines antagonism from 24 h concentration–response data with DHT held at its EC50 (~1 nM), again emphasizing an hours-to-24 h detection window for transcriptional inhibition (van Tongeren et al., 2022).

Developing genital tubercle (days scale): In mice, prenatal flutamide during a discrete programming window (within E13.5–E16.5) alters expression of multiple GT genes (22 of 88 assayed at E15.5), including marked down-regulation of Indian Hedgehog (Ihh); these measurements are made over gestational days rather than minutes or hours (Zheng et al., 2015). In rats, continuous in utero exposure to low-dose flutamide (3–6 mg/kg/day from GD7) produces prenatal antiandrogenic phenotypes by GD21 and region-specific changes in Ar/Esr1 expression in the GT, again mapping effects across gestational days (Elmelund et al., 2025). The broader developmental context for timing sensitivity (the “programming window”) is established in rats using windowed in utero flutamide exposures, with masculinization endpoints affected when exposure occurs in early/mid windows but not late, underscoring day- rather than hour-scale sensitivity (Welsh et al., 2008).

Known Feedforward/Feedback loops influencing this KER
Define whether there are known positive or negative feedback mechanisms involved and what is understood about their time-course and homeostatic limits. More help

Systemic level: Pure AR antagonists reduce androgenic negative feedback at the hypothalamo–pituitary level, provoking rises in LH and testicular androgens that can counteract peripheral antagonism; this limitation is overcome by combining with an LHRH agonist to block gonadotropin secretion (Labrie, 1984; Séguin et al., 1981; Simard et al., 1986) . Mechanistically, antiandrogens prevent androgen-stabilized AR from activating target genes by blocking the ligand-induced conformational changes needed for transcriptional activation (Kelce & Wilson, 1997). Together, these points support the inference that HPG-axis compensation (higher testosterone/DHT) could partially offset AR antagonism in genital tubercle if antagonist exposure is insufficient relative to the increased androgen drive.

Local GT level: At the level of the developing genital tubercle, defined negative/positive feedback circuits that directly regulate AR’s own transcriptional output have not been delineated; rather, available evidence points to pathway cross-talk and relay downstream of AR. In mice, prenatal flutamide during the critical programming window alters expression of multiple GT transcripts in Hedgehog, FGF, Wnt, and BMP pathways and markedly reduces Ihh; conditional deletion of Ihh demasculinizes the penis, indicating a mesenchymal–epithelial relay of androgen signals rather than a mapped AR-centric feedback loop (Zheng et al., 2015). In rats, continuous prenatal flutamide at 3–6 mg/kg/day produces region-specific changes in Ar and Esr1 expression within the GT alongside prenatal hypospadias, consistent with local steroid-signaling interplay but without defining a closed feedback or feedforward circuit controlling AR transcription (Elmelund et al., 2025). These transcriptional and spatial effects occur within defined gestational windows when androgen signaling programs masculinization, reinforcing the importance of timing but not yet establishing an intra-GT feedback architecture for AR transcription (Welsh et al., 2008; Zheng et al., 2015).

Domain of Applicability

A free-text section of the KER description that the developers can use to explain their rationale for the taxonomic, life stage, or sex applicability structured terms. More help

Taxonomic Applicability This is most empirically supported in rodents (rat, mouse), for which direct in vivo developmental studies with AR antagonists exist (Welsh et al., 2008; Rider et al., 2009; Zheng et al., 2015; Matsushita et al., 2018; Hashimoto et al., 2019; Rodriguez et al., 2012). It is biologically plausible across all therian mammals given the high conservation of AR structure and function, the conserved role of androgens in GT/phallus masculinization, and the clinical evidence from humans with androgen insensitivity (Hughes et al., 2012; Gottlieb et al., 2012).

Lifestage Applicability In rats the masculinization programming window occurs during E15.5–E19.5; only antiandrogen exposure within this fetal window induces hypospadias/cryptorchidism and reduces penile length in males, and AGD reductions map to this same period (Welsh et al., 2008).  In mice, a prenatal AR-dependent window (approximately E13.5–E16.5) governs urethral tube closure and stromal patterning; a subsequent neonatal window controls growth of the glans via AR/ERα balance, such that either AR disruption or ERα activation can cause micropenis (Zheng et al., 2015). Mouse reviews and summaries place male-specific GT patterning and urethral canalization around E16.5 (Matsushita et al., 2018; Hashimoto et al., 2019). Although many penile features in mice differentiate postnatally, specification of penile identity is prenatal and androgen-dependent (Rodriguez et al., 2012).  The KER is not applicable to postnatal or adult life stages in the context of GT masculinization, as the GT has already differentiated by parturition.

Sex Applicability Male (empirically supported and of regulatory significance for GT masculinization). Early-stage embryonic applicability to bipotential GT in both sexes is biologically plausible but less studied and of less regulatory significance.

References

List of the literature that was cited for this KER description. More help

Agrawal, H., Thakur, K., Mitra, S., Mitra, D., Keswani, C., Sircar, D., ... & Roy, P. (2022). Evaluation of (Anti) androgenic Activities of Environmental Xenobiotics in Milk Using a Human Liver Cell Line and Androgen Receptor-Based Promoter-Reporter Assay. ACS omega, 7(45), 41531-41547.

Blaschko, S. D., Cunha, G. R., & Baskin, L. S. (2012). Molecular mechanisms of external genitalia development. Differentiation, 84(3), 261-268. https://doi.org/10.1016/j.diff.2012.06.003

Bohl, C. E., Gao, W., Miller, D. D., Bell, C. E., & Dalton, J. T. (2005). Structural basis for antagonism and resistance of bicalutamide in prostate cancer. Proceedings of the National Academy of Sciences, 102(17), 6201-6206. https://doi.org/10.1073/pnas.0500381102

Brinkmann, A. O., Blok, L. J., de Ruiter, P. E., Doesburg, P., Steketee, K., Berrevoets, C. A., & Trapman, J. (1999). Mechanisms of androgen receptor activation and function. Journal of Steroid Biochemistry and Molecular Biology, 69(1-6), 307-313. https://doi.org/10.1016/s0960-0760(99)00049-7

Deslypere, J. P., Young, M., Wilson, J. D., & McPhaul, M. J. (1992). Testosterone and 5 alpha-dihydrotestosterone interact differently with the androgen receptor to enhance transcription of the MMTV-CAT reporter gene. Molecular and Cellular Endocrinology, 88(1-3), 15-22. https://doi.org/10.1016/0303-7207(92)90004-p

Elmelund, E., Draskau, M. K., Berg, M., Strand, I. W., Black, J. R., Axelstad, M., ... & Svingen, T. (2025). Androgen receptor antagonist flutamide modulates estrogen receptor alpha expression in distinct regions of the hypospadiac rat penis. Frontiers in Endocrinology, 16, 1654965.

Gottlieb, B., Beitel, L. K., Nadarajah, A., Paliouras, M., & Trifiro, M. (2012). The androgen receptor gene mutations database: 2012 update. Human Mutation, 33(5), 887-894. https://doi.org/10.1002/humu.22046

Gray, L. E., Jr., Furr, J., Lambright, C. S., Sampson, H., Hannas, B. R., & Wilson, V. S. (2022). Quantification of the uncertainties in extrapolating from in vitro androgen receptor antagonism to in vivo Hershberger assay endpoints and adverse reproductive development in male rats. Toxicological Sciences, Volume 176, Issue 2, August 2020, Pages 297–311, https://doi.org/10.1093/toxsci/kfaa067

Haraguchi, R., Suzuki, K., Murakami, R., Sakai, M., Kamikawa, M., Kengaku, M., Sekine, K., Kawano, H., Kato, S., Ueno, N., & Yamada, G. (2000). Molecular analysis of external genitalia formation: the role of fibroblast growth factor (Fgf) genes during genital tubercle formation. Development, 127(11), 2471-2479. https://doi.org/10.1242/dev.127.11.2471

Hashimoto, D., Hyuga, T., Acebedo, A. R., Alcantara, M. C., Suzuki, K., & Yamada, G. (2019). Developmental mutant mouse models for external genitalia formation. Congenital Anomalies, 59, 74–80. https://doi.org/10.1111/cga.12319

Heinlein, C. A., & Chang, C. (2002). Androgen receptor (AR) coregulators: an overview. Endocrine Reviews, 23(2), 175-200. https://doi.org/10.1210/edrv.23.2.0460

Hosokawa S, Murakami M, Ineyama M, Yamada T, Yoshitake A, Yamada H, Miyamoto J (1993) The affinity of procymidone to androgen receptor in rats and mice. J Toxicol Sci 18:83–93

Hughes, I. A., Davies, J. D., Bunch, T. I., Pasterski, V., Mastroyannopoulou, K., & MacDougall, J. (2012). Androgen insensitivity syndrome. The Lancet, 380(9851), 1419-1428. https://doi.org/10.1016/S0140-6736(12)60071-3

Kelce, W. R., Monosson, E., Gamcsik, M. P., Laws, S. C., & Gray, L. E. Jr. (1994). Environmental hormone disruptors: evidence that vinclozolin developmental toxicity is mediated by antiandrogenic metabolites. Toxicology and Applied Pharmacology, 126(2), 276-285. https://doi.org/10.1006/taap.1994.1117

Kelce, W. R., & Wilson, E. M. (1997). Environmental antiandrogens: developmental effects, molecular mechanisms, and clinical implications. Journal of Molecular Medicine, 75(3), 198-207. https://doi.org/10.1007/s001090050104

Kim, K. S., Liu, W., Cunha, G. R., Russell, D. W., Huang, H., Shapiro, E., & Baskin, L. S. (2002). Expression of the androgen receptor and 5 alpha-reductase type 2 in the developing human fetal penis and urethra. Cell and Tissue Research, 307(2), 145-153. https://doi.org/10.1007/s004410100464

Labrie, F. (1984). A new approach in the hormonal treatment of prostate cancer: complete instead of partial blockade of androgens. International journal of andrology, 7(1), 1-4.

Masiello, D., Cheng, S., Bubley, G. J., Lu, M. L., & Balk, S. P. (2002). Bicalutamide functions as an androgen receptor antagonist by assembly of a transcriptionally inactive receptor. Journal of Biological Chemistry, 277(29), 26321-26326. https://doi.org/10.1074/jbc.M203310200

Matsushita, S., Suzuki, K., Murashima, A., et al. (2018). Regulation of masculinization: Androgen signalling for external genitalia development. Nature Reviews Urology, 15, 358–368. https://doi.org/10.1038/s41585-018-0008-y

Petiot, A., Perriton, C. L., Dickson, C., & Cohn, M. J. (2005). Development of the mammalian urethra is controlled by Fgfr2-IIIb. Development, 132(10), 2441-2450. https://doi.org/10.1242/dev.01778

Quigley, C. A., De Bellis, A., Marschke, K. B., el-Awady, M. K., Wilson, E. M., & French, F. S. (1995). Androgen receptor defects: historical, clinical, and molecular perspectives. Endocrine Reviews, 16(3), 271-321. https://doi.org/10.1210/edrv-16-3-271

Rider, C. V., Wilson, V. S., Howdeshell, K. L., Hotchkiss, A. K., Furr, J. R., Lambright, C. R., & Gray, L. E. Jr. (2009). Cumulative effects of in utero administration of mixtures of "antiandrogens" on male rat reproductive development. Toxicologic Pathology, 37(1), 100-113. https://doi.org/10.1177/0192623308329478

Rodriguez, E., Weiss, D. A., Ferretti, M., Wang, H., Menshenina, J., Risbridger, G., Handelsman, D., Cunha, G., & Baskin, L. (2012). Specific morphogenetic events in mouse external genitalia sex differentiation are responsive/dependent upon androgens and/or estrogens. Differentiation, 84(3), 269–279. https://doi.org/10.1016/j.diff.2012.07.003

Séguin, C., Cusan, L., Belanger, A., Kelly, P. A., Labrie, F., & Raynaud, J. P. (1981). Additive inhibitory effects of treatment with an LHRH agonist and an antiandrogen on androgen-dependent issues in the rat. Molecular and Cellular Endocrinology, 21(1), 37-41.

Seifert, A. W., Bouldin, C. M., Choi, K. S., Harfe, B. D., & Bhatt, D. L. (2008). Multiphasic and tissue-specific roles of sonic hedgehog in cloacal septation and external genitalia development. Development, 135(23), 3777-3787.

Shang, Y., Myers, M., & Brown, M. (2002). Formation of the androgen receptor transcription complex. Molecular Cell, 9(3), 601-610. https://doi.org/10.1016/s1097-2765(02)00471-9

van den Driesche, S., Walker, M., McKinnell, C., Scott, H. M., Eddie, S. L., Mitchell, R. T., Seckl, J. R., Drake, A. J., Smith, L. B., Anderson, R. A., & Sharpe, R. M. (2012). Proposed role for COUP-TFII in regulating fetal Leydig cell steroidogenesis, perturbation of which leads to masculinization disorders in rodents. PLoS ONE, 7(5), e37064. https://doi.org/10.1371/journal.pone.0037064

van Tongeren, T. C., Carmichael, P. L., Rietjens, I. M., & Li, H. (2022). Next generation risk assessment of the anti-androgen flutamide including the contribution of its active metabolite hydroxyflutamide. Frontiers in Toxicology, 4, 881235.

Welsh, M., Saunders, P. T., Fisken, M., Scott, H. M., Hutchison, G. R., Smith, L. B., & Sharpe, R. M. (2008). Identification in rats of a programming window for reproductive tract masculinization, disruption of which leads to hypospadias and cryptorchidism. Journal of Clinical Investigation, 118(4), 1479-1490. https://doi.org/10.1172/JCI34241

Wilson, V. S., Lambright, C., Furr, J., Ostby, J., Wood, C., Humphrey, S., & Gray, L. E. Jr. (2004). Phthalate ester-induced gubernacular lesions are associated with reduced insl3 gene expression in the fetal rat testis. Toxicology Letters, 146(3), 207-215. https://doi.org/10.1016/j.toxlet.2003.09.012

Wong, C., Kelce, W. R., Sar, M., & Wilson, E. M. (1995). Androgen receptor antagonist versus agonist activities of the fungicide vinclozolin relative to hydroxyflutamide. Journal of Biological Chemistry, 270(34), 19998-20003. https://doi.org/10.1074/jbc.270.34.19998

Zheng, Z., Armfield, B. A., & Cohn, M. J. (2015). Timing of androgen receptor disruption and estrogen exposure underlies a spectrum of congenital penile anomalies. Proceedings of the National Academy of Sciences, 112(52), E7194-E7203.