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Racca JD, Chen YS, Brabender AR, Battistin U, Weiss MA, Georgiadis MM. Role of nucleobase-specific interactions in binding and bending of DNA by human male sex-determination factor SRY. J Biol Chem 2024:107683. [PMID: 39168182 DOI: 10.1016/j.jbc.2024.107683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 08/04/2024] [Accepted: 08/06/2024] [Indexed: 08/23/2024] Open
Abstract
Y-chromosome-encoded master transcription factor SRY functions in the embryogenesis of therian mammals to initiate male development. Through interactions of its conserved high mobility-group (HMG) box within a widened DNA minor groove, SRY and related Sox factors induce sharp bends at specific DNA target sites. Here, we present the crystal structure of the SRY HMG domain bound to a DNA site containing consensus element 5'-ATTGTT. The structure contains three complexes in the asymmetric unit; in each complex, SRY forms 10 hydrogen bonds with minor-groove base atoms in 5'-CATTGT/ACAATG-3', shifting the recognition sequence by one base pair (italics). These nucleobase interactions involve conserved residues Arg7, Asn10, and Tyr74 on one side of intercalated Ile13 (the cantilever side chain), and Arg20, Asn32 and Ser36 on the other. Unlike the less-bent NMR structure, DNA bend angles of the distinct box-DNA complexes range from 69-84°, similar to those observed in homologous Sox domain-DNA structures. Electrophoretic studies indicate that respective substitutions of Asn32, Ser36 or Tyr74 by Ala exhibit slightly attenuated specific DNA-binding affinity and bend angles (70-73°) relative to WT (79°). By contrast, respective substitutions of Arg7, Asn10 or Arg20 by Ala markedly impaired DNA-binding affinity in association with much smaller DNA bend angles (53-65°). In a rodent cell-based model of the embryonic gonadal ridge, full-length SRY variants bearing these respective, Ala substitutions exhibited significantly decreased transcriptional activation of SRY's principal target gene (Sox9). Together, our findings suggest that nucleobase-specific hydrogen bonds by SRY are critical for specific DNA binding, bending, and transcriptional activation.
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Affiliation(s)
- Joseph D Racca
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Adam R Brabender
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Umberto Battistin
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202.
| | - Millie M Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202.
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Chen YS, Racca JD, Weiss MA. Tenuous Transcriptional Threshold of Human Sex Determination. I. SRY and Swyer Syndrome at the Edge of Ambiguity. Front Endocrinol (Lausanne) 2022; 13:945030. [PMID: 35957822 PMCID: PMC9360328 DOI: 10.3389/fendo.2022.945030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/22/2022] [Indexed: 11/28/2022] Open
Abstract
Male sex determination in mammals is initiated by SRY, a Y-encoded transcription factor. The protein contains a high-mobility-group (HMG) box mediating sequence-specific DNA bending. Mutations causing XY gonadal dysgenesis (Swyer syndrome) cluster in the box and ordinarily arise de novo. Rare inherited variants lead to male development in one genetic background (the father) but not another (his sterile XY daughter). De novo and inherited mutations occur at an invariant Tyr adjoining the motif's basic tail (box position 72; Y127 in SRY). In SRY-responsive cell lines CH34 and LNCaP, de novo mutations Y127H and Y127C reduced SRY activity (as assessed by transcriptional activation of principal target gene Sox9) by 5- and 8-fold, respectively. Whereas Y127H impaired testis-specific enhancer assembly, Y127C caused accelerated proteasomal proteolysis; activity was in part rescued by proteasome inhibition. Inherited variant Y127F was better tolerated: its expression was unperturbed, and activity was reduced by only twofold, a threshold similar to other inherited variants. Biochemical studies of wild-type (WT) and variant HMG boxes demonstrated similar specific DNA affinities (within a twofold range), with only subtle differences in sharp DNA bending as probed by permutation gel electrophoresis and fluorescence resonance-energy transfer (FRET); thermodynamic stabilities of the free boxes were essentially identical. Such modest perturbations are within the range of species variation. Whereas our cell-based findings rationalize the de novo genotype-phenotype relationships, a molecular understanding of inherited mutation Y127F remains elusive. Our companion study uncovers cryptic biophysical perturbations suggesting that the para-OH group of Y127 anchors a novel water-mediated DNA clamp.
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Racca JD, Chatterjee D, Chen YS, Rai RK, Yang Y, Georgiadis MM, Haas E, Weiss MA. Tenuous transcriptional threshold of human sex determination. II. SRY exploits water-mediated clamp at the edge of ambiguity. Front Endocrinol (Lausanne) 2022; 13:1029177. [PMID: 36568077 PMCID: PMC9771472 DOI: 10.3389/fendo.2022.1029177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022] Open
Abstract
Y-encoded transcription factor SRY initiates male differentiation in therian mammals. This factor contains a high-mobility-group (HMG) box, which mediates sequence-specific DNA binding with sharp DNA bending. A companion article in this issue described sex-reversal mutations at box position 72 (residue 127 in human SRY), invariant as Tyr among mammalian orthologs. Although not contacting DNA, the aromatic ring seals the domain's minor wing at a solvent-exposed junction with a basic tail. A seeming paradox was posed by the native-like biochemical properties of inherited Swyer variant Y72F: its near-native gene-regulatory activity is consistent with the father's male development, but at odds with the daughter's XY female somatic phenotype. Surprisingly, aromatic rings (Y72, F72 or W72) confer higher transcriptional activity than do basic or polar side chains generally observed at solvated DNA interfaces (Arg, Lys, His or Gln). Whereas biophysical studies (time-resolved fluorescence resonance energy transfer and heteronuclear NMR spectroscopy) uncovered only subtle perturbations, dissociation of the Y72F complex was markedly accelerated relative to wild-type. Studies of protein-DNA solvation by molecular-dynamics (MD) simulations of an homologous high-resolution crystal structure (SOX18) suggest that Y72 para-OH anchors a network of water molecules at the tail-DNA interface, perturbed in the variant in association with nonlocal conformational fluctuations. Loss of the Y72 anchor among SRY variants presumably "unclamps" its basic tail, leading to (a) rapid DNA dissociation despite native affinity and (b) attenuated transcriptional activity at the edge of sexual ambiguity. Conservation of Y72 suggests that this water-mediated clamp operates generally among SRY and metazoan SOX domains.
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Affiliation(s)
- Joseph D. Racca
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
- *Correspondence: Joseph D. Racca, ; Michael A. Weiss,
| | - Deepak Chatterjee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Ratan K. Rai
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Yanwu Yang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Millie M. Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Elisha Haas
- Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
| | - Michael A. Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
- *Correspondence: Joseph D. Racca, ; Michael A. Weiss,
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Thomson E, Zhao L, Chen YS, Longmuss E, Ng ET, Sreenivasan R, Croft B, Song X, Sinclair A, Weiss M, Koopman P, Pelosi E. Generation and mutational analysis of a transgenic mouse model of human SRY. Hum Mutat 2021; 43:362-379. [PMID: 34918413 DOI: 10.1002/humu.24318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/27/2021] [Accepted: 12/15/2021] [Indexed: 01/31/2023]
Abstract
SRY is the Y-chromosomal gene that determines male sex development in humans and most other mammals. After three decades of study, we still lack a detailed understanding of which domains of the SRY protein are required to engage the pathway of gene activity leading to testis development. Some insight has been gained from the study of genetic variations underlying differences/disorders of sex determination (DSD), but the lack of a system of experimentally generating SRY mutations and studying their consequences in vivo has limited progress in the field. To address this issue, we generated a mouse model carrying a human SRY transgene able to drive testis determination in XX mice. Using CRISPR-Cas9 gene editing, we generated novel genetic modifications in each of SRY's three domains (N-terminal, HMG box, and C-terminal) and performed a detailed analysis of their molecular and cellular effects on embryonic testis development. Our results provide new functional insights unique to human SRY and present a versatile and powerful system in which to functionally analyze variations of SRY including known and novel pathogenic variants found in DSD.
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Affiliation(s)
- Ella Thomson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.,Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Liang Zhao
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Yen-Shan Chen
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Enya Longmuss
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Ee Ting Ng
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Rajini Sreenivasan
- Murdoch Children's Research Institute and Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Brittany Croft
- Murdoch Children's Research Institute and Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Xin Song
- Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Andrew Sinclair
- Murdoch Children's Research Institute and Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Michael Weiss
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Peter Koopman
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Emanuele Pelosi
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.,Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
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Racca JD, Chen YS, Yang Y, Phillips NB, Weiss MA. Human Sex Determination at the Edge of Ambiguity: INHERITED XY SEX REVERSAL DUE TO ENHANCED UBIQUITINATION AND PROTEASOMAL DEGRADATION OF A MASTER TRANSCRIPTION FACTOR. J Biol Chem 2016; 291:22173-22195. [PMID: 27576690 DOI: 10.1074/jbc.m116.741959] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Indexed: 12/15/2022] Open
Abstract
A general problem is posed by analysis of transcriptional thresholds governing cell fate decisions in metazoan development. A model is provided by testis determination in therian mammals. Its key step, Sertoli cell differentiation in the embryonic gonadal ridge, is initiated by SRY, a Y-encoded architectural transcription factor. Mutations in human SRY cause gonadal dysgenesis leading to XY female development (Swyer syndrome). Here, we have characterized an inherited mutation compatible with either male or female somatic phenotypes as observed in an XY father and XY daughter, respectively. The mutation (a crevice-forming substitution at a conserved back surface of the SRY high mobility group box) markedly destabilizes the domain but preserves specific DNA affinity and induced DNA bend angle. On transient transfection of diverse human and rodent cell lines, the variant SRY exhibited accelerated proteasomal degradation (relative to wild type) associated with increased ubiquitination; in vitro susceptibility to ubiquitin-independent ("default") cleavage by the 20S core proteasome was unchanged. The variant's gene regulatory activity (as assessed in a cellular model of the rat embryonic XY gonadal ridge) was reduced by 2-fold relative to wild-type SRY at similar levels of mRNA expression. Chemical proteasome inhibition restored native-like SRY expression and transcriptional activity in association with restored occupancy of a sex-specific enhancer element in principal downstream gene Sox9, demonstrating that the variant SRY exhibits essentially native activity on a per molecule basis. Our findings define a novel mechanism of impaired organogenesis, accelerated ubiquitin-directed proteasomal degradation of a master transcription factor leading to a developmental decision poised at the edge of ambiguity.
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Affiliation(s)
- Joseph D Racca
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Yen-Shan Chen
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Yanwu Yang
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Nelson B Phillips
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Michael A Weiss
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
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Affiliation(s)
| | - Pablo A. Martinez
- Departamento de Biologia; Universidade Federal de Sergipe; Av. Marechal Rondon, S/N - Jardim Rosa Elze São Cristóvão 49100-000 Brazil
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Racca JD, Chen YS, Maloy JD, Wickramasinghe N, Phillips NB, Weiss MA. Structure-function relationships in human testis-determining factor SRY: an aromatic buttress underlies the specific DNA-bending surface of a high mobility group (HMG) box. J Biol Chem 2014; 289:32410-29. [PMID: 25258310 DOI: 10.1074/jbc.m114.597526] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human testis determination is initiated by SRY, a Y-encoded architectural transcription factor. Mutations in SRY cause 46 XY gonadal dysgenesis with female somatic phenotype (Swyer syndrome) and confer a high risk of malignancy (gonadoblastoma). Such mutations cluster in the SRY high mobility group (HMG) box, a conserved motif of specific DNA binding and bending. To explore structure-function relationships, we constructed all possible substitutions at a site of clinical mutation (W70L). Our studies thus focused on a core aromatic residue (position 15 of the consensus HMG box) that is invariant among SRY-related HMG box transcription factors (the SOX family) and conserved as aromatic (Phe or Tyr) among other sequence-specific boxes. In a yeast one-hybrid system sensitive to specific SRY-DNA binding, the variant domains exhibited reduced (Phe and Tyr) or absent activity (the remaining 17 substitutions). Representative nonpolar variants with partial or absent activity (Tyr, Phe, Leu, and Ala in order of decreasing side-chain volume) were chosen for study in vitro and in mammalian cell culture. The clinical mutation (Leu) was found to markedly impair multiple biochemical and cellular activities as respectively probed through the following: (i) in vitro assays of specific DNA binding and protein stability, and (ii) cell culture-based assays of proteosomal degradation, nuclear import, enhancer DNA occupancy, and SRY-dependent transcriptional activation. Surprisingly, however, DNA bending is robust to this or the related Ala substitution that profoundly impairs box stability. Together, our findings demonstrate that the folding, trafficking, and gene-regulatory function of SRY requires an invariant aromatic "buttress" beneath its specific DNA-bending surface.
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Affiliation(s)
- Joseph D Racca
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Yen-Shan Chen
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - James D Maloy
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Nalinda Wickramasinghe
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Nelson B Phillips
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Michael A Weiss
- From the Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
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Asero P, Calogero AE, Condorelli RA, Mongioi' L, Vicari E, Lanzafame F, Crisci R, La Vignera S. Relevance of genetic investigation in male infertility. J Endocrinol Invest 2014; 37:415-27. [PMID: 24458834 DOI: 10.1007/s40618-014-0053-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Accepted: 12/19/2013] [Indexed: 01/24/2023]
Abstract
Genetic causes can be directly responsible for various clinical conditions of male infertility and spermatogenic impairment. With the increased use of assisted reproduction technologies our understanding of genetic basis of male infertility has large implications not only for understanding the causes of infertility but also in determining the prognosis and management of such couples. For these reasons, the genetic investigations represent today an essential and useful tool in the treatment of male infertility. Several evidences are available for the clinical practice regarding the diagnosis; however, there are less information relative to the treatment of the genetic causes of male infertility. Focus of this review is to discuss the main and more common genetic causes of male infertility to better direct the genetics investigation in the treatment of spermatogenic impairment.
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Affiliation(s)
- P Asero
- Sezione di Endocrinologia, Andrologia e Medicina Interna, Dipartimento di Scienze Mediche e Pediatriche, Università di Catania, Policlinico "G. Rodolico," Bldg 4, Rm 2C18, Via S. Sofia 78, 95123, Catania, Italy
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Rajender S, Gupta NJ, Chakrabarty B, Singh L, Thangaraj K. L712V mutation in the androgen receptor gene causes complete androgen insensitivity syndrome due to severe loss of androgen function. Steroids 2013; 78:1288-92. [PMID: 24055831 DOI: 10.1016/j.steroids.2013.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 09/02/2013] [Accepted: 09/06/2013] [Indexed: 10/26/2022]
Abstract
Inability to respond to the circulating androgens is named as androgen insensitivity syndrome (AIS). Mutations in the androgen receptor (AR) gene are the most common cause of AIS. A cause and effect relationship between some of these mutations and the AIS phenotype has been proven by in vitro studies. Several other mutations have been identified, but need to be functionally validated for pathogenicity. Screening of the AR mutations upon presumptive diagnosis of AIS is recommended. We analyzed a case of complete androgen insensitivity syndrome (CAIS) for mutations in the AR gene. Sequencing of the entire coding region revealed C>G mutation (CTT-GTT) at codon 712 (position according to the NCBI database) in exon 4 of the gene, resulting in replacement of leucine with valine in the ligand-binding domain of the AR protein. No incidence of this mutation was observed in 230 normal male individuals analyzed for comparison. In vitro androgen binding and transactivation assays using mutant clone showed approximately 71% loss of ligand binding and about 76% loss of transactivation function. We conclude that CAIS in this individual was due to L712V substitution in the androgen receptor protein.
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Affiliation(s)
- Singh Rajender
- Endocrinology Division, Central Drug Research Institute (Council of Scientific and Industrial Research), India.
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Inherited human sex reversal due to impaired nucleocytoplasmic trafficking of SRY defines a male transcriptional threshold. Proc Natl Acad Sci U S A 2013; 110:E3567-76. [PMID: 24003159 DOI: 10.1073/pnas.1300828110] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Human testis determination is initiated by SRY (sex determining region on Y chromosome). Mutations in SRY cause gonadal dysgenesis with female somatic phenotype. Two subtle variants (V60L and I90M in the high-mobility group box) define inherited alleles shared by an XY sterile daughter and fertile father. Whereas specific DNA binding and bending are unaffected in a rat embryonic pre-Sertoli cell line, the variants exhibited selective defects in nucleocytoplasmic shuttling due to impaired nuclear import (V60L; mediated by Exportin-4) or export (I90M; mediated by chromosome region maintenance 1). Decreased shuttling limits nuclear accumulation of phosphorylated (activated) SRY, in turn reducing occupancy of DNA sites regulating Sertoli-cell differentiation [the testis-specific SRY-box 9 (Sox9) enhancer]. Despite distinct patterns of biochemical and cell-biological perturbations, V60L and I90M each attenuated Sox9 expression in transient transfection assays by twofold. Such attenuation was also observed in studies of V60A, a clinical variant associated with ovotestes and hence ambiguity between divergent cell fates. This shared twofold threshold is reminiscent of autosomal syndromes of transcription-factor haploinsufficiency, including XY sex reversal associated with mutations in SOX9. Our results demonstrate that nucleocytoplasmic shuttling of SRY is necessary for robust initiation of testicular development. Although also characteristic of ungulate orthologs, such shuttling is not conserved among rodents wherein impaired nuclear export of the high-mobility group box and import-dependent phosphorylation are compensated by a microsatellite-associated transcriptional activation domain. Human sex reversal due to subtle defects in the nucleocytoplasmic shuttling of SRY suggests that its transcriptional activity lies near the edge of developmental ambiguity.
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Chen YS, Racca JD, Sequeira PW, Phillips NB, Weiss MA. Microsatellite-encoded domain in rodent Sry functions as a genetic capacitor to enable the rapid evolution of biological novelty. Proc Natl Acad Sci U S A 2013; 110:E3061-70. [PMID: 23901118 PMCID: PMC3746911 DOI: 10.1073/pnas.1300860110] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The male program of therian mammals is determined by Sry, a transcription factor encoded by the Y chromosome. Specific DNA binding is mediated by a high mobility group (HMG) box. Expression of Sry in the gonadal ridge activates a Sox9-dependent gene regulatory network leading to testis formation. A subset of Sry alleles in superfamily Muroidea (order Rodentia) is remarkable for insertion of an unstable DNA microsatellite, most commonly encoding (as in mice) a CAG repeat-associated glutamine-rich domain. We provide evidence, based on an embryonic pre-Sertoli cell line, that this domain functions at a threshold length as a genetic capacitor to facilitate accumulation of variation elsewhere in the protein, including the HMG box. The glutamine-rich domain compensates for otherwise deleterious substitutions in the box and absence of nonbox phosphorylation sites to ensure occupancy of DNA target sites. Such compensation enables activation of a male transcriptional program despite perturbations to the box. Whereas human SRY requires nucleocytoplasmic shuttling and coupled phosphorylation, mouse Sry contains a defective nuclear export signal analogous to a variant human SRY associated with inherited sex reversal. We propose that the rodent glutamine-rich domain has (i) fostered accumulation of cryptic intragenic variation and (ii) enabled unmasking of such variation due to DNA replicative slippage. This model highlights genomic contingency as a source of protein novelty at the edge of developmental ambiguity and may underlie emergence of non-Sry-dependent sex determination in the radiation of Muroidea.
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Affiliation(s)
| | | | | | | | - Michael A. Weiss
- Departments of Biochemistry
- Biomedical Engineering, and
- Medicine, Case Western Reserve University, Cleveland, OH 44106
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Vasu VR, Saranya B, Jayashankar M, Munirajan AK, Santhiya ST. A Novel Splice Site and Two Known Mutations of Androgen Receptor Gene in Sex-Reversed XY Phenotype. Genet Test Mol Biomarkers 2012; 16:749-55. [DOI: 10.1089/gtmb.2011.0292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Vidya Rendheer Vasu
- Department of Genetics, Dr. ALM. PG. Institute of Basic Medical Sciences, University of Madras, Chennai, India
| | - Balachandran Saranya
- Department of Genetics, Dr. ALM. PG. Institute of Basic Medical Sciences, University of Madras, Chennai, India
| | - Meena Jayashankar
- Department of Medical Genetics, Institute of Obstetrics and Gynecology, Madras Medical College, Government Hospital for Women and Children, Chennai, India
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Phillips NB, Racca J, Chen YS, Singh R, Jancso-Radek A, Radek JT, Wickramasinghe NP, Haas E, Weiss MA. Mammalian testis-determining factor SRY and the enigma of inherited human sex reversal: frustrated induced fit in a bent protein-DNA complex. J Biol Chem 2011; 286:36787-807. [PMID: 21849498 DOI: 10.1074/jbc.m111.260091] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian testis-determining factor SRY contains a high mobility group box, a conserved eukaryotic motif of DNA bending. Mutations in SRY cause XY gonadal dysgenesis and somatic sex reversal. Although such mutations usually arise de novo in spermatogenesis, some are inherited and so specify male development in one genetic background (the father) but not another (the daughter). Here, we describe the biophysical properties of a representative inherited mutation, V60L, within the minor wing of the L-shaped domain (box position 5). Although the stability and DNA binding properties of the mutant domain are similar to those of wild type, studies of SRY-induced DNA bending by subnanosecond time-resolved fluorescence resonance energy transfer (FRET) revealed enhanced conformational fluctuations leading to long range variation in bend angle. (1)H NMR studies of the variant protein-DNA complex demonstrated only local perturbations near the mutation site. Because the minor wing of SRY folds on DNA binding, the inherited mutation presumably hinders induced fit. Stopped-flow FRET studies indicated that such frustrated packing leads to accelerated dissociation of the bent complex. Studies of SRY-directed transcriptional regulation in an embryonic gonadal cell line demonstrated partial activation of downstream target Sox9. Our results have demonstrated a nonlocal coupling between DNA-directed protein folding and protein-directed DNA bending. Perturbation of this coupling is associated with a genetic switch poised at the threshold of activity.
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Affiliation(s)
- Nelson B Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Reshmi SC, Miller JL, Deplewski D, Close C, Henderson LJ, Littlejohn E, Schwartz S, Waggoner DJ. Evidence of a mechanism for isodicentric chromosome Y formation in a 45,X/46,X,idic(Y)(p11.31)/46,X,del(Y)(p11.31) mosaic karyotype. Eur J Med Genet 2011; 54:161-4. [DOI: 10.1016/j.ejmg.2010.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 11/01/2010] [Indexed: 11/30/2022]
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Irmak MK. Self-fertilization in human: Having a male embryo without a father. Med Hypotheses 2010; 75:448-51. [DOI: 10.1016/j.mehy.2010.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Accepted: 04/03/2010] [Indexed: 10/19/2022]
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Singh R, Singh P, Gupta NJ, Chakrabarty B, Singh L, Thangaraj K. C601S mutation in the androgen receptor results in partial loss of androgen function. J Steroid Biochem Mol Biol 2010; 122:359-63. [PMID: 20493947 DOI: 10.1016/j.jsbmb.2010.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 05/12/2010] [Accepted: 05/12/2010] [Indexed: 11/25/2022]
Abstract
The present study was undertaken on a case of partial androgen insensitivity syndrome to look at the etiology of the disorder. The patient exhibited a female phenotype despite 46,XY chromosome complement. Direct DNA sequencing of coding region of the androgen receptor gene in this case revealed a 2329G>C substitution (cDNA sequence reference) in exon 3 of the gene. The substitution resulted in replacement of Cys with Ser at codon 601 of the ligand-binding domain of the protein. Analyses on 200 control samples revealed absence of this substitution(s). In vitro assays were done using COS-1 cells. The mutation resulted in partial (∼40%) loss of ligand-binding and significant (∼70%) loss of downstream transactivation function. The mutation was absent in the controls. The findings are particularly interesting since another substitution at the same codon (TGC-TTC) has been reported in association with complete androgen insensitivity syndrome.
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Affiliation(s)
- Rajender Singh
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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18
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Shibata Y, Paul-Prasanth B, Suzuki A, Usami T, Nakamoto M, Matsuda M, Nagahama Y. Expression of gonadal soma derived factor (GSDF) is spatially and temporally correlated with early testicular differentiation in medaka. Gene Expr Patterns 2010; 10:283-9. [PMID: 20601164 DOI: 10.1016/j.gep.2010.06.005] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 06/09/2010] [Accepted: 06/10/2010] [Indexed: 11/28/2022]
Abstract
In the teleost fish, medaka (Oryzias latipes), the sex is genetically determined at the time of fertilization. The males are heterogametic with XY chromosome composition, while females are of XX chromosome composition. The male sexual differentiation is initiated in XY embryos of medaka by the sex-determining gene Dmy. In this study, we have cloned the gonadal soma derived factor (Gsdf) from medaka and characterized its expression pattern during the initiation of morphological testicular differentiation. By real-time PCR, an XY-specific up-regulation was detected in the expression levels of Gsdf in the whole embryos of medaka at 6days post fertilization (dpf), coincident with the initiation of testicular differentiation in the XY gonads. Whole mount and section in situ hybridizations reaffirmed that Gsdf was expressed exclusively in primordial gonads of only the genetic males at 6dpf. Conversely, the expression of Gsdf was found to be very weak in the XX gonads during embryogenesis. Importantly, Gsdf and Dmy were found to be co-localized in the same somatic cells in the XY gonads. When the XY embryos were treated with estradiol-17beta, in order to reverse their phenotypic sex, a decline was observed in the expression of Gsdf in these embryos by real-time PCR.
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Affiliation(s)
- Yasushi Shibata
- Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
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19
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Allelic exchange of pheromones and their receptors reprograms sexual identity in Cryptococcus neoformans. PLoS Genet 2010; 6:e1000860. [PMID: 20195516 PMCID: PMC2829064 DOI: 10.1371/journal.pgen.1000860] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 01/26/2010] [Indexed: 11/19/2022] Open
Abstract
Cell type specification is a fundamental process that all cells must carry out to ensure appropriate behaviors in response to environmental stimuli. In fungi, cell identity is critical for defining "sexes" known as mating types and is controlled by components of mating type (MAT) loci. MAT-encoded genes function to define sexes via two distinct paradigms: 1) by controlling transcription of components common to both sexes, or 2) by expressing specially encoded factors (pheromones and their receptors) that differ between mating types. The human fungal pathogen Cryptococcus neoformans has two mating types (a and alpha) that are specified by an extremely unusual MAT locus. The complex architecture of this locus makes it impossible to predict which paradigm governs mating type. To identify the mechanism by which the C. neoformans sexes are determined, we created strains in which the pheromone and pheromone receptor from one mating type (a) replaced the pheromone and pheromone receptor of the other (alpha). We discovered that these "alpha(a)" cells effectively adopt a new mating type (that of a cells); they sense and respond to alpha factor, they elicit a mating response from alpha cells, and they fuse with alpha cells. In addition, alpha(a) cells lose the alpha cell type-specific response to pheromone and do not form germ tubes, instead remaining spherical like a cells. Finally, we discovered that exogenous expression of the diploid/dikaryon-specific transcription factor Sxi2a could then promote complete sexual development in crosses between alpha and alpha(a) strains. These data reveal that cell identity in C. neoformans is controlled fully by three kinds of MAT-encoded proteins: pheromones, pheromone receptors, and homeodomain proteins. Our findings establish the mechanisms for maintenance of distinct cell types and subsequent developmental behaviors in this unusual human fungal pathogen.
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20
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Rajender S, Gupta NJ, Chakrabarty B, Singh L, Thangaraj K. Ala 586 Asp mutation in androgen receptor disrupts transactivation function without affecting androgen binding. Fertil Steril 2009; 91:933.e23-8. [DOI: 10.1016/j.fertnstert.2008.10.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 10/16/2008] [Accepted: 10/17/2008] [Indexed: 10/21/2022]
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21
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Case report: WT1 exon 6 truncation mutation and ambiguous genitalia in a patient with Denys-Drash syndrome. Curr Opin Pediatr 2008; 20:103-6. [PMID: 18197048 DOI: 10.1097/mop.0b013e3282f357eb] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Denys-Drash syndrome is a rare genetic disorder featuring the triad of congenital nephropathy, Wilms tumor, and intersex disorders (XY under-virilization or XY female). Denys-Drash syndrome is associated with constitutional mutations in the Wilms tumor suppressor gene WT1. Unlike WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) syndrome, with its complete deletion of one copy of WT1, Denys-Drash syndrome is generally caused by a dominant-negative mutation. We present a new case of Denys-Drash syndrome in a patient initially diagnosed with XY ambiguous genitalia/partial androgen insensitivity syndrome, who was found to have a novel nonsense mutation in exon 6 leading to a stop codon and hence a truncated protein. Based on lessons learned from this patient, the diagnosis of Denys-Drash syndrome should be considered in the presence of ambiguous genitalia and partial androgen insensitivity.
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22
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Yan Z, Hull CM, Sun S, Heitman J, Xu J. The mating type-specific homeodomain genes SXI1 alpha and SXI2a coordinately control uniparental mitochondrial inheritance in Cryptococcus neoformans. Curr Genet 2007; 51:187-95. [PMID: 17186242 DOI: 10.1007/s00294-006-0115-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2006] [Accepted: 11/28/2006] [Indexed: 02/04/2023]
Abstract
In the great majority of sexual eukaryotes, mitochondrial genomes are inherited almost exclusively from a single parent. While many hypotheses have been proposed to explain this phenomenon, very little is known about the genetic elements controlling uniparental mitochondria inheritance. In the bipolar, isogamous basidiomycete yeast Cryptococcus neoformans, progeny from crosses between strains of mating type a (MATa) and mating type alpha (MATalpha) typically inherit mitochondrial DNA (mtDNA) from the MATa parent. We recently demonstrated that a mating type alpha (MATalpha)-specific gene SXI1a, controls mitochondrial inheritance in C. neoformans. Here, we show that another homeodomain gene SXI2a in the alternative mating type MATa is also required for uniparental mtDNA inheritance in this fungus. Disruption of SXI2a resulted in biparental mtDNA inheritance in the zygote population with significant numbers of progeny inheriting mtDNA from the MATa parent, the MATalpha parent, and both the MATa and the MATalpha parents. In addition, progeny from same-sex mating between MATalpha strains showed a biparental mitochondrial inheritance pattern. Our results suggest that SXI1alpha and SXI2a coordinately control uniparental mitochondrial inheritance in C. neoformans.
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Affiliation(s)
- Zhun Yan
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
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23
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Abstract
Androgen receptor (AR) gene has been extensively studied in diverse clinical conditions. In addition to the point mutations, trinucleotide repeat (CAG and GGN) length polymorphisms have been an additional subject of interest and controversy among geneticists. The polymorphic variations in triplet repeats have been associated with a number of disorders, but at the same time contradictory findings have also been reported. Further, studies on the same disorder in different populations have generated different results. Therefore, combined analysis or review of the published studies has been of much value to extract information on the significance of variations in the gene in various clinical conditions. AR genetics has been reviewed extensively but until now review articles have focused on individual clinical categories such as androgen insensitivity, male infertility, prostate cancer, and so on. We have made the first effort to review most the aspects of AR genetics. The impact of androgens in various disorders and polymorphic variations in the AR gene is the main focus of this review. Additionally, the correlations observed in various studies have been discussed in the light of in vitro evidences available for the effect of AR gene variations on the action of androgens.
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MESH Headings
- Androgen-Insensitivity Syndrome/genetics
- Androgen-Insensitivity Syndrome/physiopathology
- Bone Diseases, Metabolic/genetics
- Bone Diseases, Metabolic/physiopathology
- Breast Neoplasms/genetics
- Breast Neoplasms/physiopathology
- Cognition Disorders/genetics
- Cognition Disorders/physiopathology
- Digestive System Diseases/genetics
- Digestive System Diseases/physiopathology
- Female
- Genital Neoplasms, Female/genetics
- Genital Neoplasms, Female/physiopathology
- Genital Neoplasms, Male/genetics
- Genital Neoplasms, Male/physiopathology
- Humans
- Infertility, Male/genetics
- Male
- Muscular Atrophy, Spinal/genetics
- Muscular Atrophy, Spinal/physiopathology
- Phenotype
- Point Mutation
- Polycystic Ovary Syndrome/genetics
- Polycystic Ovary Syndrome/physiopathology
- Polymorphism, Genetic
- Pre-Eclampsia/genetics
- Pre-Eclampsia/physiopathology
- Pregnancy
- Receptors, Androgen/genetics
- Receptors, Androgen/physiology
- Schizophrenia/genetics
- Schizophrenia/physiopathology
- Testosterone/deficiency
- Trinucleotide Repeats
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Affiliation(s)
- Singh Rajender
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India
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24
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King V, Goodfellow PN, Pearks Wilkerson AJ, Johnson WE, O'Brien SJ, Pecon-Slattery J. Evolution of the male-determining gene SRY within the cat family Felidae. Genetics 2007; 175:1855-67. [PMID: 17277366 PMCID: PMC1855139 DOI: 10.1534/genetics.106.066779] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 01/16/2007] [Indexed: 11/18/2022] Open
Abstract
In most placental mammals, SRY is a single-copy gene located on the Y chromosome and is the trigger for male sex determination during embryonic development. Here, we present comparative genomic analyses of SRY (705 bp) along with the adjacent noncoding 5' flank (997 bp) and 3' flank (948 bp) in 36 species of the cat family Felidae. Phylogenetic analyses indicate that the noncoding genomic flanks and SRY closely track species divergence. However, several inconsistencies are observed in SRY. Overall, the gene exhibits purifying selection to maintain function (omega = 0.815) yet SRY is under positive selection in two of the eight felid lineages. SRY has low numbers of nucleotide substitutions, yet most encode amino acid changes between species, and four different species have significantly altered SRY due to insertion/deletions. Moreover, fixation of nonsynonymous substitutions between sister taxa is not consistent and may occur rapidly, as in the case of domestic cat, or not at all over long periods of time, as observed within the Panthera lineage. The former resembles positive selection during speciation, and the latter purifying selection to maintain function. Thus, SRY evolution in cats likely reflects the different phylogeographic histories, selection pressures, and patterns of speciation in modern felids.
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Affiliation(s)
- V King
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, United Kingdom
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25
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Abstract
Unlike nuclear genes and genomes, the inheritance of organelle genes and genomes does not follow Mendel's laws. In this mini-review, I summarize recent research progress on the patterns and mechanisms of the inheritance of organelle genes and genomes. While most sexual eukaryotes show uniparental inheritance of organelle genes and genomes in some progeny at least part of the time, increasing evidence indicates that strictly uniparental inheritance is rare and that organelle inheritance patterns are very diverse and complex. In contrast with the predominance of uniparental inheritance in multicellular organisms, organelle genes in eukaryotic microorganisms, such as protists, algae, and fungi, typically show a greater diversity of inheritance patterns, with sex-determining loci playing significant roles. The diverse patterns of inheritance are matched by the rich variety of potential mechanisms. Indeed, many factors, both deterministic and stochastic, can influence observed patterns of organelle inheritance. Interestingly, in multicellular organisms, progeny from interspecific crosses seem to exhibit more frequent paternal leakage and biparental organelle genome inheritance than those from intraspecific crosses. The recent observation of a sex-determining gene in the basidiomycete yeast Cryptococcus neoformans, which controls mitochondrial DNA inheritance, has opened up potentially exciting research opportunities for identifying specific molecular genetic pathways that control organelle inheritance, as well as for testing evolutionary hypotheses regarding the prevalence of uniparental inheritance of organelle genes and genomes.
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Affiliation(s)
- Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON, Canada.
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26
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Whyte J, Roberts R, Rosenfeld C. Fluorescent in situ hybridization for sex chromosome determination before and after fertilization in mice. Theriogenology 2007; 67:1022-31. [PMID: 17215034 PMCID: PMC1857354 DOI: 10.1016/j.theriogenology.2006.11.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Accepted: 11/30/2006] [Indexed: 11/29/2022]
Abstract
In mice, the relative numbers of male and female pups per litter not only can vary but can probably change over the course of pregnancy in response to numerous environmental and physiological factors. As such, a technique is required to determine gender at several developmental stages. Here we describe a robust and accurate fluorescent in situ hybridization (FISH) procedure for determining chromosomal sex that can be applied with minimal modification to sperm, pre-and post-implantation conceptuses and recovered dead post-natal pups. Sperm was prepared for FISH analysis y using a modified microwave decondensation-denaturation technique. Preimplantation conceptuses (0.5dpc) were cultured to the morula stage before sexing. They were then acid-treated to remove the zona pellucida. Tissue homogenates from postimplantational conceptuses (8.5dpc) and stillborn pups were fixed to pre-etched slides. Specimens were hybridized with identical, commercially available DNA probes for the X (FITC) and Y (Cy3) chromosomes. Sperm ratios met the expected value of 0.5 when determined by using XY FISH. Preimplantation conceptuses pre-treated with pepsin yielded distinct fluorescence of X and Y chromosomes in morulae, whereas microwave decondensation resulted in loss of conceptuses from the slide. Both 4.0 and 8.5dpc conceptuses displayed mean sex ratios of 0.5. Post-natal FISH analysis allowed gender identification of pups that could not be sexed due to developmental abnormalities or partial cannibalism. FISH analysis of sperm and of multiple conceptuses or post-natal tissue provided a cost-effective, accurate alternative to PCR-based sex determination.
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Affiliation(s)
- J.J. Whyte
- Department of Biomedical Sciences, 440F Christopher S. Bond Life Sciences Center, University of Missouri-Columbia, 1201 Rollins Road, Columbia, MO 65211, USA
| | - R.M. Roberts
- Department of Animal Sciences, Christopher S. Bond Life Sciences Center, University of Missouri-Columbia, Columbia, MO 65211, USA
- Department of Biochemistry, Christopher S. Bond Life Sciences Center, University Of Missouri-Columbia, Columbia, MO 65211, USA
| | - C.S. Rosenfeld
- Department of Biomedical Sciences, 440F Christopher S. Bond Life Sciences Center, University of Missouri-Columbia, 1201 Rollins Road, Columbia, MO 65211, USA
- * Corresponding author. Tel.: +1 573 882 6798; fax: +1 573 884 9345. E-mail address: (C.S. Rosenfeld)
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27
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Nelson CP, Gearhart JP. Current views on evaluation, management, and gender assignment of the intersex infant. ACTA ACUST UNITED AC 2006; 1:38-43. [PMID: 16474465 DOI: 10.1038/ncpuro0028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Accepted: 09/22/2004] [Indexed: 11/09/2022]
Abstract
In recent years, traditional views regarding the management of infants with intersex conditions have been challenged. Some of these patients have gender dysphoria and gender conversion, although most adults with intersex consider themselves to be either male or female. Hormonal and genetic factors may have a more important role in gender identity and sexual satisfaction than previously recognized, whereas the importance of phallus size to male gender identity and sexual satisfaction may have been overestimated. The impact of androgen imprinting on the developing brain is uncertain, but it is likely to be significant. The issue of genital surgery in infancy is controversial, although many adult patients concur that infancy is the best time for such procedures. Several reports indicate that the functional outcomes of genital surgery are poor, although more recently developed surgical techniques may achieve better results. Good communication between physicians, patients, and families regarding intersex conditions is paramount. We review current understanding of the evaluation and management of intersex conditions.
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Affiliation(s)
- Caleb P Nelson
- Brady Urological Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA.
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28
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Modi D, Shah C, Sachdeva G, Gadkar S, Bhartiya D, Puri C. Ontogeny and cellular localization of SRY transcripts in the human testes and its detection in spermatozoa. Reproduction 2006; 130:603-13. [PMID: 16264091 DOI: 10.1530/rep.1.00413] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The sex-determining region on the Y (SRY) gene is unequivocally designated as the testis-determining factor in mammals; however, its roles beyond sex determination, if any, have been hitherto unknown. To determine whether SRY has any roles beyond sex determination, herein the expression of SRY mRNA was investigated in the midtrimester human fetal, infantile and adult testes as well as in ejaculated spermatozoa. High levels of SRY transcripts were in situ localized to the Sertoli cells of the developing testis at 9 weeks of gestation, and the expression persisted at comparable levels throughout the midtrimester (until 22 weeks) and also in the testis of an infant at 3 months of age. The germ cells and other somatic cells in the testes of fetuses and the infant were negative for SRY expression. The mRNA for SRY was detected in the spermatogenic cells, particularly the spermatogonia and the round spermatids; the expression was negligible in the meiotic stages. A single transcript of approximately 1.2 kb was detected in the adult testes and isolated spermatogonial cells. In the adult testis, in situ hybridization (ISH) studies revealed a switch in the cellular localization of SRY transcripts. SRY transcripts were also demonstrable by RT-PCR of RNA from ejaculated human spermatozoa. ISH revealed the presence of SRY transcripts in the midpiece of 50% of ejaculated sperm. These results suggest that SRY may have extensive roles in male reproductive physiology, such as maturation of fetal testis, spermatogenesis, sperm maturation and early embryonic development.
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Affiliation(s)
- D Modi
- Stem Cell Biology Department, National Institute for Research in Reproductive Health, Indian Council of Medical Research, Mumbai, Maharashtra, India.
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29
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Val P, Swain A. Mechanisms of Disease: normal and abnormal gonadal development and sex determination in mammals. ACTA ACUST UNITED AC 2005; 2:616-27. [PMID: 16474549 DOI: 10.1038/ncpuro0354] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Accepted: 09/22/2005] [Indexed: 11/09/2022]
Abstract
Sex differentiation in mammals occurs in three steps. The first is the establishment of chromosomal sex at fertilization, followed by the differentiation of the gonad into an ovary or testis, and finally the establishment of the phenotypic sex of the embryo and adult, which is regulated by the gonad. Disruption of any of these stages gives rise to sexual ambiguities that include 46,XY pure gonadal dysgenesis, 46,XX true hermaphroditism, and variable degrees of intersexuality. In this review, we focus on the development of the mammalian gonad from a bipotential primordium that differentiates into either an ovary or a testis. We describe the recent increase in our knowledge of the genetic defects that directly affect gonadal development, sex determination, and sex differentiation, with emphasis on the comparison of genetic studies in mice with studies of naturally occurring mutations in humans.
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Affiliation(s)
- Pierre Val
- Institute of Cancer Research, London, UK
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30
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Sexual dimorphism of craniological characters in Eurasian badgers, Meles spp. (Carnivora, Mustelidae). ZOOL ANZ 2005. [DOI: 10.1016/j.jcz.2004.12.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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31
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Yan Z, Hull CM, Heitman J, Sun S, Xu J. SXI1alpha controls uniparental mitochondrial inheritance in Cryptococcus neoformans. Curr Biol 2005; 14:R743-4. [PMID: 15380081 DOI: 10.1016/j.cub.2004.09.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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32
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Mayer JA, Chuong CM, Widelitz R. Rooster feathering, androgenic alopecia, and hormone-dependent tumor growth: what is in common? Differentiation 2004; 72:474-88. [PMID: 15617560 PMCID: PMC4380229 DOI: 10.1111/j.1432-0436.2004.07209003.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Different epithelial organs form as a result of epithelial-mesenchymal interactions and share a common theme modulated by variations (Chuong ed. In Molecular Basis of Epithelial Appendage Morphogenesis, 1998). One of the major modulators is the sex hormone pathway that acts on the prototype signaling pathway to alter organ phenotypes. Here, we focus on how the sex hormone pathway may interface with epithelia morphogenesis-related signaling pathways. We first survey these sex hormone-regulated morphogenetic processes in various epithelial organs. Sexual dimorphism of hairs and feathers has implications in sexual selection. Diseases of these pathways result in androgenic alopecia, hirsutism, henny feathering, etc. The growth and development of mammary glands, prostate glands, and external genitalia essential for reproductive function are also dependent on sex hormones. Diseases affecting these organs include congenital anomalies and hormone-dependent breast and prostate cancers. To study the role of sex hormones in new growth in the context of system biology/pathology, an in vivo model in which organ formation starts from stem cells is essential. With recent developments (Yu et al. (2002) The morphogenesis of feathers. Nature 420:308-312), the growth of tail feathers in roosters and hens has become a testable model in which experimental manipulations are possible. We show exemplary data of differences in their growth rate, proliferative cell population, and signaling molecule expression. Working hypotheses are proposed on how the sex hormone pathways may interact with growth pathways. It is now possible to test these hypotheses using the chicken model to learn fundamental mechanisms on how sex hormones affect organogenesis, epithelial organ cycling, and growth-related tumorigenesis.
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Affiliation(s)
- Julie Ann Mayer
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Cheng-Ming Chuong
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Randall Widelitz
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
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33
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Naidoo T, Chan Y, Jayasinghe Y, Moore P, Hutson J, Warne G. Gonadal dysgenesis with a difference. J Pediatr Endocrinol Metab 2004; 17:787-91. [PMID: 15237715 DOI: 10.1515/jpem.2004.17.5.787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We report here an exceptional clinical finding of a 46,XY phenotypic female with complete gonadal dysgenesis, but who was found unexpectedly to have absence of the uterus and posterior vagina. Extensive review of current and past literature failed to confirm other reports of this variant form of complete gonadal dysgenesis.
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Affiliation(s)
- Theresa Naidoo
- University of Tasmania Medical School, Hobart, Australia
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34
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Affiliation(s)
- David T MacLaughlin
- Pediatric Surgical Research Laboratories and the Pediatric Surgical Services, Massachusetts General Hospital and Harvard Medical School, Boston 02114, USA.
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35
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Reiner WG. Gender identity and sex assignment: a reappraisal for the 21st century. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 511:175-89; discussion 189-97. [PMID: 12575762 DOI: 10.1007/978-1-4615-0621-8_11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- William G Reiner
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, MD, USA
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36
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Zhao LJ, Zhang S, Chinnadurai G. Sox9 transactivation and testicular expression of a novel human gene, KIAA0800. J Cell Biochem 2002; 86:277-89. [PMID: 12111997 DOI: 10.1002/jcb.10214] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Sry and Sox9 sex-determination factors initiate and promote testis differentiation by gene transactivation through similar promoter elements. However, knowledge is limited concerning what genes are regulated by Sry/Sox9 in the testis. Identification and characterization of Sry/Sox9-regulated genes are critical for understanding sexual differentiation. We now demonstrate that a novel human gene, KIAA0800, is preferentially expressed in the testis and is transactivated by Sox9. The KIAA0800 promoter is repressed by an upstream element involving a polyT track and two Alu repeats. Two specific Sox9-bindings sites have been identified in the KIAA0800 promoter by using DNaseI footprinting assays and gel electrophoretic mobility shift assays. Sox9 transactivation of the KIAA0800 promoter appears to be exerted mainly through the relief of promoter repression. Genes homologous to the human KIAA0800 exist in organisms with differentiated sex tissues including mouse, Drosophila, and C. elegans, but not in unicellular organisms, including yeast and bacteria. Further, our recent sequence analysis shows that KIAA0800 protein is 97% identical between human and mouse. Thus, KIAA0800 is a novel Sox9-activated gene that is evolutionarily conserved and potentially involved in sexual differentiation.
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Affiliation(s)
- Ling-Jun Zhao
- Institute for Molecular Virology, St. Louis University Health Sciences Center, 3681 Park Avenue, Missouri 63110, USA.
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Hull CM, Davidson RC, Heitman J. Cell identity and sexual development in Cryptococcus neoformans are controlled by the mating-type-specific homeodomain protein Sxi1alpha. Genes Dev 2002; 16:3046-60. [PMID: 12464634 PMCID: PMC187491 DOI: 10.1101/gad.1041402] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Virulence in the human fungal pathogen Cryptococcus neoformans is associated with the alpha mating type. Studies to identify the properties of alpha cells that enhance pathogenesis have led to the identification of a mating-type locus of unusually large size and distinct architecture. Here, we demonstrate that the previously identified MATalpha components are insufficient to regulate sexual differentiation, and we identify a novel alpha-specific regulator, SXI1alpha. Our data show that SXI1alpha establishes alpha cell identity and controls progression through the sexual cycle, and we discover that ectopic expression of SXI1alpha in a cells is sufficient to drive a/alpha sexual development. SXI1alpha is the first example of a key regulator of cell identity and sexual differentiation in C. neoformans, and its identification and characterization lead to a new model of how cell fate and the sexual cycle are controlled in C. neoformans.
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Affiliation(s)
- Christina M Hull
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Abstract
This paper considers a number of key concepts relevant to biological determinants of human sexuality, including sexual differentiation, brain mechanisms involved in sexual response, the role of sex hormones, and the sexual effects of drugs. The paper concludes with consideration of how little is known about the interaction between biology and culture in shaping human sexuality, and the need for research in this area.
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Affiliation(s)
- John Bancroft
- The Kinsey Institute for Research in Sex, Gender and Reproduction, Morrison Hall 313, Indiana University, Bloomington, IN 47405, USA.
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Affiliation(s)
- Kenneth J Zucker
- Child and Adolescent Gender Identity Clinic, Child Psychiatry Program, Centre for Addiction and Mental Health-Clarke Division, Toronto, Ontario, Canada.
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40
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Abstract
In humans, sexual differentiation is directed by SRY, a master regulatory gene located at the Y chromosome. This gene initiates the male pathway or represses the female pathway by regulating the transcription of downstream genes; however, the precise mechanisms by which SRY acts are largely unknown. Moreover, several genes have recently been implicated in the development of the bipotential gonad even before SRY is expressed. In some individuals, the normal process of sexual differentiation is altered and a sex reversal disorder is observed. These subjects present the chromosomes of one sex but the physical attributes of the other. Over the past years, considerable progress has been achieved in the molecular characterization of these disorders by using a combination of strategies including cell biology, animal models, and by studying patients with these pathologic entities.
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MESH Headings
- Animal Diseases/embryology
- Animal Diseases/genetics
- Animals
- DNA-Binding Proteins/physiology
- Disorders of Sex Development/genetics
- Disorders of Sex Development/pathology
- Female
- Genes, sry
- Genotype
- Gonadal Dysgenesis, 46,XX/embryology
- Gonadal Dysgenesis, 46,XX/epidemiology
- Gonadal Dysgenesis, 46,XX/genetics
- Gonadal Dysgenesis, 46,XX/pathology
- Gonadal Dysgenesis, 46,XX/therapy
- Gonadal Dysgenesis, 46,XX/veterinary
- Gonads/embryology
- High Mobility Group Proteins/genetics
- High Mobility Group Proteins/physiology
- Humans
- Karyotyping
- Mice
- Mice, Knockout
- Mosaicism
- Mutation
- Nuclear Proteins
- Phenotype
- SOX9 Transcription Factor
- Sex Determination Processes
- Sex Differentiation/genetics
- Sex Differentiation/physiology
- Sex-Determining Region Y Protein
- Transcription Factors/genetics
- Transcription Factors/physiology
- Translocation, Genetic/genetics
- Vertebrates/physiology
- X Chromosome/ultrastructure
- Y Chromosome/genetics
- Y Chromosome/ultrastructure
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Affiliation(s)
- J C Zenteno-Ruiz
- Department of Genetics, Hospital General de Mexico-Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
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Penton-Voak IS, Perrett DI. Male facial attractiveness: Perceived personality and shifting female preferences for male traits across the menstrual cycle. ADVANCES IN THE STUDY OF BEHAVIOR 2001. [DOI: 10.1016/s0065-3454(01)80008-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Abstract
Sex assignment in the newborn with ambiguous genitalia has been based on the adequacy of the phallus in the male, potential fertility in the female, and cosmetic appearance of the reconstructed genitalia. Recent data from both the neurosciences and from clinical research, however, casts doubt on the validity of such criteria for clinical decision making. Current knowledge suggests a need to shift away from the current clinical approach and to incorporate these new data into decisions based on a broader understanding of the etiology of gender identity. Recognition of the primacy of psychosocial and psychosexual developmental outcomes for children with ambiguous genitalia is lending direction to longitudinal outcomes research. New approaches to sex assignment have been suggested, and the paradigm for sex assignment in the newborn period is in transition.
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Affiliation(s)
- W G Reiner
- Department of Psychiatry, Johns Hopkins Hospital, Baltimore, Maryland 21287-3325, USA.
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van der Schoot P, Payne AP, Kersten W. Sex difference in target seeking behavior of developing cremaster muscles and the resulting first visible sign of somatic sexual differentiation in marsupial mammals. Anat Rec (Hoboken) 1999; 255:130-41. [PMID: 10359514 DOI: 10.1002/(sici)1097-0185(19990601)255:2<130::aid-ar3>3.0.co;2-l] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Cremaster muscles are present in both male and female developing and adult marsupial mammals. They are complex structures and composed of several distinct bundles of striated muscle fibers provided with: (1) a distinct and extensive innervation; (2) a distinct blood vascular supply; (3) a distinct tendineous origin on the anterosuperior iliac spine; and (4) distinct target structures. The muscles thus seem to be separate anatomical entities and not a part of one or more of the layers of the ventral abdominal wall musculature. Cremaster muscles in males are elongated, are larger than in females, and for the most part are a component of the funiculus spermaticus. They insert on the distal part of the tunica vaginalis. The distal parts of the muscles in females are flattened ("fan shaped") and insert over a broad area on the dorsal borders of the mammary glands. Muscles in males have no relation whatsoever to the male mammary glandular rudiments. Muscles in females are attached at the base of the uterine round ligament. The remarkable sex difference in target structures of marsupial cremaster muscles becomes noticeable during perinatal life when outgrowing muscles take a different path in males and females. The initial appearance of this sexually dimorphic trait precedes the sexual differentiation of the genital ducts and external genitalia. In fetal males, the cremaster muscles grow in the direction of the site where scrotal bulges initially appear in the subcutaneous layers and later on the inguinal skin surface. They also take the gubernacular core of the ventral abdominal wall and the attached peritoneal epithelium with them during this outgrowth process. Consequently, this results in the development of a slitlike evagination of the abdominal lumen as the primary step to development of the processus vaginalis, while the testis and adjacent mesonephros and its duct are still attached to the posterior abdominal wall. In fetal females, the outgrowing cremaster muscles pass along the gubernacular core and, subsequently, this structure develops further as the tip (attached to the tubo-uterine junction) of the intra-abdominally protruding and further developing uterine round ligament. The female cremaster muscles grow further into caudal direction to shape a dorsal border of the developing mammary glands. The early onset of this sexually dimorphic outgrowth of cremaster muscles indicates that the "classical hormones" of sexual differentiation (anti-Müllerian hormone [AMH] and steroidal androgens) are not involved in this process. It could thus depend on primary genetic control with male development associated with the male-limited activity of genes on the Y-chromosomes and female development as the default process. Alternatively, the process in males could be under the control of an as yet unidentified third fetal testicular hormone involved in sexual differentiation processes which must then show an unexpectely early (i.e., perinatal) onset of its secretion.
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Affiliation(s)
- P van der Schoot
- Department of Herd Health & Reproduction, Faculty of Veterinary Sciences, University of Utrecht, The Netherlands.
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Gaston SM, Loughlin KR. Now what do we do with all these genes? Yeast-based two-hybrid analysis: an emerging technology for molecular urology in the post-genome era. Urology 1999; 53:835-42. [PMID: 10197871 DOI: 10.1016/s0090-4295(98)00604-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
By the year 2005, the Human Genome Project is expected to have mapped and sequenced all of the estimated 100,000 genes that encode the various proteins found in human cells. Defining the role of each gene, and using that information to redirect its action when therapeutic intervention is required, is one of the major assignments for molecular medicine and molecular urology in the post-genome era. This challenge to determine gene function, and to do it cost-effectively and on a large scale, has driven development of new technologies that can more efficiently flag genes that are likely targets for therapeutic intervention. Yeast-based genetic assays that detect protein-protein interactions in vivo offer many of the features required of a practical "gene-flagging" strategy for identifying genes that might be functionally manipulated to achieve therapeutic goals. In the past few years, the yeast-based assays collectively referred to as "two-hybrid interaction traps" or simply "two-hybrid systems" have become increasingly important tools for experimental analysis of gene function. This review presents an overview of the principles of yeast-based two-hybrid analysis, examines some specific applications of the technique of interest to urologic investigators, and discusses some key points that a basic urologic investigator new to the technology would want to consider when designing or evaluating a yeast-based two-hybrid project.
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Affiliation(s)
- S M Gaston
- Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139, USA
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