scholarly journals Transcriptional Regulation of the Y-Linked Mammalian Testis-Determining Gene SRY

2021 ◽  
pp. 1-9
Author(s):  
Naoki Okashita ◽  
Makoto Tachibana

Mammalian male sex differentiation is triggered during embryogenesis by the activation of the Y-linked testis-determining gene <i>SRY</i>. Since insufficient or delayed expression of <i>SRY</i> results in XY gonadal sex reversal, accurate regulation of <i>SRY</i> is critical for male development in XY animals. In humans, dysregulation of <i>SRY</i> may cause disorders of sex development. Mouse <i>Sry</i> is the most intensively studied mammalian model of sex determination. <i>Sry</i> expression is controlled in a spatially and temporally stringent manner. Several transcription factors play a key role in sex determination as trans-acting factors for <i>Sry</i> expression. In addition, recent studies have shown that several epigenetic modifications of <i>Sry</i> are involved in sex determination as cis-acting factors for <i>Sry</i> expression. Herein, we review the current understanding of transcription factor- and epigenetic modifier-mediated regulation of <i>SRY</i>/<i>Sry</i> expression.

2021 ◽  
pp. 1-18
Author(s):  
Meshi Ridnik ◽  
Stefan Schoenfelder ◽  
Nitzan Gonen

Sex determination is the process by which an initial bipotential gonad adopts either a testicular or ovarian cell fate. The inability to properly complete this process leads to a group of developmental disorders classified as disorders of sex development (DSD). To date, dozens of genes were shown to play roles in mammalian sex determination, and mutations in these genes can cause DSD in humans or gonadal sex reversal/dysfunction in mice. However, exome sequencing currently provides genetic diagnosis for only less than half of DSD patients. This points towards a major role for the non-coding genome during sex determination. In this review, we highlight recent advances in our understanding of non-coding, cis-acting gene regulatory elements and discuss how they may control transcriptional programmes that underpin sex determination in the context of the 3-dimensional folding of chromatin. As a paradigm, we focus on the <i>Sox9</i> gene, a prominent pro-male factor and one of the most extensively studied genes in gonadal cell fate determination.


2020 ◽  
Vol 103 (6) ◽  
pp. 1300-1313
Author(s):  
Yi-Han Li ◽  
Tsung-Ming Chen ◽  
Bu-Miin Huang ◽  
Shang-Hsun Yang ◽  
Chia-Ching Wu ◽  
...  

Abstract Fibroblast growth factor 9 (FGF9) is an autocrine/paracrine growth factor that plays critical roles in embryonic and organ developments and is involved in diverse physiological events. Loss of function of FGF9 exhibits male-to-female sex reversal in the transgenic mouse model and gain of FGF9 copy number was found in human 46, XX sex reversal patient with disorders of sex development. These results suggested that FGF9 plays a vital role in male sex development. Nevertheless, how FGF9/Fgf9 expression is regulated during testis determination remains unclear. In this study, we demonstrated that human and mouse SRY bind to −833 to −821 of human FGF9 and −1010 to −998 of mouse Fgf9, respectively, and control FGF9/Fgf9 mRNA expression. Interestingly, we showed that mouse SRY cooperates with SF1 to regulate Fgf9 expression, whereas human SRY-mediated FGF9 expression is SF1 independent. Furthermore, using an ex vivo gonadal culture system, we showed that FGF9 expression is sufficient to switch cell fate from female to male sex development in 12–16 tail somite XX mouse gonads. Taken together, our findings provide evidence to support the SRY-dependent, fate-determining role of FGF9 in male sex development.


Genetics ◽  
2019 ◽  
Vol 213 (4) ◽  
pp. 1317-1327 ◽  
Author(s):  
Yingjie Zhou ◽  
Wei Sun ◽  
Han Cai ◽  
Haisheng Bao ◽  
Yu Zhang ◽  
...  

Anti-Müllerian hormone (Amh, or Müllerian-inhibiting substance, Mis), a member of TGF-β superfamily, has been well documented in some vertebrates as initiator or key regulator in sexual development, and particularly in fish. However, its functional role has not yet been identified in reptiles. Here, we characterized the Amh gene in the Chinese soft-shelled turtle Pelodiscus sinensis, a typical reptilian species exhibiting ZZ/ZW sex chromosomes. The messenger RNA of Amh was initially expressed in male embryonic gonads by stage 15, preceding gonadal sex differentiation, and exhibited a male-specific expression pattern throughout embryogenesis. Moreover, Amh was rapidly upregulated during female-to-male sex reversal induced by aromatase inhibitor letrozole. Most importantly, Amh loss of function by RNA interference led to complete feminization of genetic male (ZZ) gonads, suppression of the testicular marker Sox9, and upregulation of the ovarian regulator Cyp19a1. Conversely, overexpression of Amh in ZW embryos resulted in female-to-male sex reversal, characterized by the formation of a testis structure, ectopic activation of Sox9, and a remarkable decline in Cyp19a1. Collectively, these findings provide the first solid evidence that Amh is both necessary and sufficient to drive testicular development in a reptilian species, P. sinensis, highlighting the significance of the TGF-β pathway in reptilian sex determination.


2020 ◽  
Vol 9 (11) ◽  
pp. 3555
Author(s):  
Pedro Acién ◽  
Maribel Acién

In this review, the elements included in both sex determination and sex differentiation are briefly analyzed, exposing the pathophysiological and clinical classification of disorders or anomalies of sex development. Anomalies in sex determination without sex ambiguity include gonadal dysgenesis, polysomies, male XX, and Klinefelter syndrome (dysgenesis and polysomies with a female phenotype; and sex reversal and Klinefelter with a male phenotype). Other infertility situations could also be included here as minor degrees of dysgenesis. Anomalies in sex determination with sex ambiguity should (usually) include testicular dysgenesis and ovotesticular disorders. Among the anomalies in sex differentiation, we include: (1) males with androgen deficiency (MAD) that correspond to those individuals whose karyotype and gonads are male (XY and testes), but the phenotype can be female due to different hormonal abnormalities. (2) females with androgen excess (FAE); these patients have ovaries and a 46,XX karyotype, but present varying degrees of external genital virilization as a result of an enzyme abnormality that affects adrenal steroid biosynthesis and leads to congenital adrenal hyperplasia; less frequently, this can be caused by iatrogenia or tumors. (3) Kallman syndrome. All of these anomalies are reviewed and analyzed herein, as well as related fertility problems.


2021 ◽  
pp. 1-11
Author(s):  
Yuta Sakae ◽  
Minoru Tanaka

Animals determine their sex genetically (GSD: genetic sex determination) and/or environmentally (ESD: environmental sex determination). Medaka (<i>Oryzias latipes</i>) employ a XX/XY GSD system, however, they display female-to-male sex reversal in response to various environmental changes such as temperature, hypoxia, and green light. Interestingly, we found that 5 days of starvation during sex differentiation caused female-to-male sex reversal. In this situation, the metabolism of pantothenate and fatty acid synthesis plays an important role in sex reversal. Metabolism is associated with other biological factors such as germ cells, HPG axis, lipids, and epigenetics, and supplys substances and acts as signal transducers. In this review, we discuss the importance of metabolism during sex differentiation and how metabolism contributes to sex differentiation.


Endocrinology ◽  
2016 ◽  
Vol 157 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Luke S. Lambeth ◽  
Kirsten R. Morris ◽  
Terry G. Wise ◽  
David M. Cummins ◽  
Terri E. O'Neil ◽  
...  

Abstract 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.


2009 ◽  
Vol 21 (9) ◽  
pp. 95
Author(s):  
L. Ludbrook ◽  
R. Sekido ◽  
R. Lovell-Badge ◽  
V. Harley

The DAX1 protein is an orphan nuclear hormone receptor expressed in developing and adult hypothalamic, pituitary, adrenal and gonadal tissues. In humans, duplication of the DAX1 gene at locus Xp21 causes Disorders of Sex Development (DSD), whereby XY individuals develop as females, due to the failure of testicular development. DAX1 acts as a co-factor for nuclear receptor-mediated transcription of steroidogenic genes. In mice, overexpression of a Dax1 transgene causes delayed testis cord formation, a milder phenotype than that seen in human (1). Exactly how DAX1 duplication interferes with typical testicular development is unclear but a ‘window' of DAX1 activity was proposed (2). In order to identify the mechanism of DAX1 action when overexpressed in the developing XY gonad, we have used both in vivo and in vitro approaches. We hypothesised that, when present in excess, DAX1 must repress the action of early testis-forming genes. We investigated the effect of Dax1 over expression, using the Dax1 transgenic mouse line, Dax1812 (1), on expression of Sox9, a critical testis-forming gene. Immunostaining of Dax1812 gonads revealed reduced Sox9 expression, suggesting excess Dax1 antagonises Sox9 upregulation during the early stages of sex determination. To determine whether antagonism of Sox9 was occurring at the transcriptional level we assessed the effect of excess Dax1 on the activity of the Testis-Specific Enhancer of Sox9 (TES), which drives Sox9 transcription in the developing XY gonad (3). In combination, the in vivo and in vitro evidence strongly suggests that Dax1, when present in excess, can repress Sox9 expression through TES and that this repression occurs through inhibition of Steroidogenic Factor-1 activity. With this work we have identified a potential mechanism for disruption of the male-specific sex determination pathway caused by DAX1 duplication and leading to DSD in XY individuals.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Oki Hayasaka ◽  
Yutaka Takeuchi ◽  
Kazuhiro Shiozaki ◽  
Kazuhiko Anraku ◽  
Tomonari Kotani

2020 ◽  
Vol 37 (1) ◽  
Author(s):  
Sarah Khan ◽  
Raafea Tafweez ◽  
Areiba Haider ◽  
Muhammad Yaqoob

Objective: To describe the mode of presentation and frequency of external genital anomalies in disorder of sex development (DSD) Methods: This cross-sectional study was conducted at Children Hospital & Institute of Child Health, Lahore from January to December, 2016 on Children with DSD above 10 years of age. A detailed history and physical examination were done. Positive findings were recorded on a predesigned proforma and analyzed by SPSS 21. Karyotyping on blood samples was done to determine their genetic sex. Results: Out of 83 DSD children, 67% (n=56) were assigned a female sex at birth of which 9% (n=5) had ambiguous genitalia. Male sex at birth was given to 33% (n=27) of which 96% (n=26) had genital ambiguity. Mode of presentation other than ambiguous genitalia were delayed puberty, amenorrhea, hirsuitism, gynaecomastia, cyclic hematuria etc. Clitoromegaly was the main finding in 62.5% (n=5) and micropenis in 45% (n=9). Karyotypic sex of 56 female sex of rearing was 46XX 80% (n=45), 45X0 13% (n=7), XXX 2% (n=1) and 46 XY in 5% (n=3). Karyotypic sex of 27 male sex of rearing was 46XY in 78% (n=21), 46XX in 15% (n=4) and 47XXY in 7% (n=2). Conclusion: Disorders of sex development presented with a wide spectrum of external genital anomalies ranging from clitoromegaly in females to micropenis and hypospadias in males. There was also an extreme diversity in mode of presentation of these cases including pubertal delay, amenorrhea in females and gender confusion disorders. doi: https://doi.org/10.12669/pjms.37.1.2991 How to cite this:Khan S, Tafweez R, Haider A, Yaqoob M. Spectrum of external genital anomalies in disorders of Sex Development at Children Hospital & Institute of Child Health, Lahore, Pakistan. Pak J Med Sci. 2021;37(1):244-249. doi: https://doi.org/10.12669/pjms.37.1.2991 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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