1
|
Kazi S, Castañeda JM, Savolainen A, Xu Y, Liu N, Qiao H, Ramirez‐Solis R, Nozawa K, Yu Z, Matzuk MM, Prunskaite‐Hyyryläinen R. MRNIP interacts with sex body chromatin to support meiotic progression, spermatogenesis, and male fertility in mice. FASEB J 2022; 36:e22479. [PMID: 35920200 PMCID: PMC9544956 DOI: 10.1096/fj.202101168rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 07/13/2022] [Accepted: 07/19/2022] [Indexed: 11/24/2022]
Abstract
Meiosis has a principal role in sexual reproduction to generate haploid gametes in both sexes. During meiosis, the cell nucleus hosts a dynamic environment where some genes are transcriptionally activated, and some are inactivated at the same time. This becomes possible through subnuclear compartmentalization. The sex body, sequestering X and Y chromosomes during male meiosis and creating an environment for the meiotic sex chromosome inactivation (MSCI) is one of the best known and studied subnuclear compartments. Herein, we show that MRNIP forms droplet-like accumulations that fuse together to create a distinct subnuclear compartment that partially overlaps with the sex body chromatin during diplotene. We demonstrate that Mrnip-/- spermatocytes have impaired DNA double-strand break (DSB) repair, they display reduced sex body formation and defective MSCI. We show that Mrnip-/- undergoes critical meiocyte loss at the diplotene stage. Furthermore, we determine that DNA DSBs (induced by SPO11) and synapsis initiation (facilitated by SYCP1) precede Mrnip expression in testes. Altogether, our findings indicate that in addition to an emerging role in DNA DSB repair, MRNIP has an essential function in spermatogenesis during meiosis I by forming drop-like accumulations interacting with the sex body.
Collapse
Affiliation(s)
- Samina Kazi
- Faculty of Biochemistry and Molecular MedicineUniversity of OuluOuluFinland
| | | | - Audrey Savolainen
- Faculty of Biochemistry and Molecular MedicineUniversity of OuluOuluFinland
| | - Yiding Xu
- Department of Comparative BiosciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
| | - Ning Liu
- Department of Comparative BiosciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
| | - Huanyu Qiao
- Department of Comparative BiosciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
| | | | - Kaori Nozawa
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTexasUSA
| | - Zhifeng Yu
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTexasUSA
- Center for Drug DiscoveryBaylor College of MedicineHoustonTexasUSA
| | - Martin M. Matzuk
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTexasUSA
- Center for Drug DiscoveryBaylor College of MedicineHoustonTexasUSA
| | | |
Collapse
|
2
|
Xu Y, Qiao H. A Hypothesis: Linking Phase Separation to Meiotic Sex Chromosome Inactivation and Sex-Body Formation. Front Cell Dev Biol 2021; 9:674203. [PMID: 34485277 PMCID: PMC8415632 DOI: 10.3389/fcell.2021.674203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 07/22/2021] [Indexed: 01/12/2023] Open
Abstract
During meiotic prophase I, X and Y chromosomes in mammalian spermatocytes only stably pair at a small homologous region called the pseudoautosomal region (PAR). However, the rest of the sex chromosomes remain largely unsynapsed. The extensive asynapsis triggers transcriptional silencing - meiotic sex chromosome inactivation (MSCI). Along with MSCI, a special nuclear territory, sex body or XY body, forms. In the early steps of MSCI, DNA damage response (DDR) factors, such as BRCA1, ATR, and γH2AX, function as sensors and effectors of the silencing signals. Downstream canonical repressive histone modifications, including methylation, acetylation, ubiquitylation, and SUMOylation, are responsible for the transcriptional repression of the sex chromosomes. Nevertheless, mechanisms of the sex-body formation remain unclear. Liquid-liquid phase separation (LLPS) may drive the formation of several chromatin subcompartments, such as pericentric heterochromatin, nucleoli, inactive X chromosomes. Although several proteins involved in phase separation are found in the sex bodies, when and whether these proteins exert functions in the sex-body formation and MSCI is still unknown. Here, we reviewed recent publications on the mechanisms of MSCI and LLPS, pointed out the potential link between LLPS and the formation of sex bodies, and discussed its implications for future research.
Collapse
Affiliation(s)
| | - Huanyu Qiao
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| |
Collapse
|
3
|
Single-Cell RNA Sequencing of the Cynomolgus Macaque Testis Reveals Conserved Transcriptional Profiles during Mammalian Spermatogenesis. Dev Cell 2020; 54:548-566.e7. [PMID: 32795394 DOI: 10.1016/j.devcel.2020.07.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/23/2020] [Accepted: 07/22/2020] [Indexed: 12/15/2022]
Abstract
Spermatogenesis is highly orchestrated and involves the differentiation of diploid spermatogonia into haploid sperm. The process is driven by spermatogonial stem cells (SSCs). SSCs undergo mitotic self-renewal, whereas sub-populations undergo differentiation and later gain competence to initiate meiosis. Here, we describe a high-resolution single-cell RNA-seq atlas of cells derived from Cynomolgus macaque testis. We identify gene signatures that define spermatogonial populations and explore self-renewal versus differentiation dynamics. We detail transcriptional changes occurring over the entire process of spermatogenesis and highlight the concerted activity of DNA damage response (DDR) pathway genes, which have dual roles in maintaining genomic integrity and effecting meiotic sex chromosome inactivation (MSCI). We show remarkable similarities and differences in gene expression during spermatogenesis with two other eutherian mammals, i.e., mouse and humans. Sex chromosome expression in the male germline in all three species demonstrates conserved features of MSCI but divergent multicopy and ampliconic gene content.
Collapse
|
4
|
A framework for high-resolution phenotyping of candidate male infertility mutants: from human to mouse. Hum Genet 2020; 140:155-182. [PMID: 32248361 DOI: 10.1007/s00439-020-02159-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 03/27/2020] [Indexed: 12/18/2022]
Abstract
Male infertility is a heterogeneous condition of largely unknown etiology that affects at least 7% of men worldwide. Classical genetic approaches and emerging next-generation sequencing studies support genetic variants as a frequent cause of male infertility. Meanwhile, the barriers to transmission of this disease mean that most individual genetic cases will be rare, but because of the large percentage of the genome required for spermatogenesis, the number of distinct causal mutations is potentially large. Identifying bona fide causes of male infertility thus requires advanced filtering techniques to select for high-probability candidates, including the ability to test causality in animal models. The mouse remains the gold standard for defining the genotype-phenotype connection in male fertility. Here, we present a best practice guide consisting of (a) major points to consider when interpreting next-generation sequencing data performed on infertile men, and, (b) a systematic strategy to categorize infertility types and how they relate to human male infertility. Phenotyping infertility in mice can involve investigating the function of multiple cell types across the testis and epididymis, as well as sperm function. These findings will feed into the diagnosis and treatment of male infertility as well as male health broadly.
Collapse
|
5
|
Ramos-Ibeas P, Pericuesta E, Peral-Sanchez I, Heras S, Laguna-Barraza R, Pérez-Cerezales S, Gutiérrez-Adán A. Longitudinal analysis of somatic and germ-cell telomere dynamics in outbred mice. Mol Reprod Dev 2019; 86:1033-1043. [PMID: 31209959 DOI: 10.1002/mrd.23218] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 11/10/2022]
Abstract
Although telomere length (TL) shortens with age in most tissues, an age-related increase in length has been described in sperm through a mechanism that is not yet fully understood. Changes in TL with age in the same individual have not been explored. This longitudinal study examines TL dynamics in somatic tissue and gametes during an entire lifespan in an outbred mouse population (from 8 to up to 114 weeks of age). Our findings indicate a reduced life expectancy in males compared to females (84.75 ± 9.23 vs. 113.16 ± 0.20 weeks) and significant variability in TL dynamics between individuals. While with aging, a clear reduction in TL was produced in somatic cells and oocytes, telomeres in sperm cells significantly lengthened. Finally, we found evidence indicating that telomere elongation in sperm during aging may be dependent on different mechanisms, such as the survival of spermatogonia with longer telomeres and the alternative lengthening of telomeres mechanism in meiotic and postmeiotic spermatogenic cells.
Collapse
Affiliation(s)
| | - Eva Pericuesta
- Departamento de Reproducción Animal, INIA, Madrid, Spain
| | | | - Sonia Heras
- Departamento de Reproducción Animal, INIA, Madrid, Spain
| | | | | | | |
Collapse
|
6
|
Matveevsky SN, Pavlova SV, Atsaeva MM, Searle JB, Kolomiets OL. Dual mechanism of chromatin remodeling in the common shrew sex trivalent (XY 1Y 2). COMPARATIVE CYTOGENETICS 2017; 11:727-745. [PMID: 29114363 PMCID: PMC5672328 DOI: 10.3897/compcytogen.v11i4.13870] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Here we focus on the XY1Y2 condition in male common shrew Sorex araneus Linnaeus, 1758, applying electron microscopy and immunocytochemistry for a comprehensive analysis of structure, synapsis and behaviour of the sex trivalent in pachytene spermatocytes. The pachytene sex trivalent consists of three distinct parts: short and long synaptic SC fragments (between the X and Y1 and between the X and Y2, respectively) and a long asynaptic region of the X in-between. Chromatin inactivation was revealed in the XY1 synaptic region, the asynaptic region of the X and a very small asynaptic part of the Y2. This inactive part of the sex trivalent, that we named the 'head', forms a typical sex body and is located at the periphery of the meiotic nucleus at mid pachytene. The second part or 'tail', a long region of synapsis between the X and Y2 chromosomes, is directed from the periphery into the nucleus. Based on the distribution patterns of four proteins involved in chromatin inactivation, we propose a model of meiotic silencing in shrew sex chromosomes. Thus, we conclude that pachytene sex chromosomes are structurally and functionally two different chromatin domains with specific nuclear topology: the peripheral inactivated 'true' sex chromosome regions (part of the X and the Y1) and more centrally located transcriptionally active autosomal segments (part of the X and the Y2).
Collapse
Affiliation(s)
- Sergey N. Matveevsky
- N.I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Gubkin str. 3, Moscow 119991, Russia
| | - Svetlana V. Pavlova
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Maret M. Atsaeva
- Chechen State University, A. Sheripov str. 32, Grozny 364051, Chechen Republic, Russia
| | - Jeremy B. Searle
- Department of Ecology and Evolutionary Biology, Corson Hall, Cornell University, Ithaca, NY 14853, USA
| | - Oxana L. Kolomiets
- N.I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Gubkin str. 3, Moscow 119991, Russia
| |
Collapse
|
7
|
Abstract
Meiosis is essential for reproduction in sexually reproducing organisms. A key stage in meiosis is the synapsis of maternal and paternal homologous chromosomes, accompanied by exchange of genetic material to generate crossovers. A decade ago, studies found that when chromosomes fail to synapse, the many hundreds of genes housed within them are transcriptionally inactivated. This process, meiotic silencing, is conserved in all mammals studied to date, but its purpose is not yet defined. Here, I review the molecular genetics of meiotic silencing and consider the many potential functions that it could serve in the mammalian germ line. In addition, I discuss how meiotic silencing influences sex differences in meiotic infertility and the profound impact that meiotic silencing has had on the evolution of mammalian sex chromosomes.
Collapse
|
8
|
Yamauchi Y, Riel JM, Ruthig VA, Ortega EA, Mitchell MJ, Ward MA. Two genes substitute for the mouse Y chromosome for spermatogenesis and reproduction. Science 2016; 351:514-6. [PMID: 26823431 DOI: 10.1126/science.aad1795] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The mammalian Y chromosome is considered a symbol of maleness, as it encodes a gene driving male sex determination, Sry, as well as a battery of other genes important for male reproduction. We previously demonstrated in the mouse that successful assisted reproduction can be achieved when the Y gene contribution is limited to only two genes, Sry and spermatogonial proliferation factor Eif2s3y. Here, we replaced Sry by transgenic activation of its downstream target Sox9, and Eif2s3y, by transgenic overexpression of its X chromosome-encoded homolog Eif2s3x. The resulting males with no Y chromosome genes produced haploid male gametes and sired offspring after assisted reproduction. Our findings support the existence of functional redundancy between the Y chromosome genes and their homologs encoded on other chromosomes.
Collapse
Affiliation(s)
- Yasuhiro Yamauchi
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, 1960 East-West Road, Honolulu, HI 96822, USA
| | - Jonathan M Riel
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, 1960 East-West Road, Honolulu, HI 96822, USA
| | - Victor A Ruthig
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, 1960 East-West Road, Honolulu, HI 96822, USA
| | - Eglė A Ortega
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, 1960 East-West Road, Honolulu, HI 96822, USA
| | - Michael J Mitchell
- Aix-Marseille Université, INSERM, GMGF UMR_S 910, 13385 Marseille, France
| | - Monika A Ward
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, 1960 East-West Road, Honolulu, HI 96822, USA.
| |
Collapse
|
9
|
Taketo T. The role of sex chromosomes in mammalian germ cell differentiation: can the germ cells carrying X and Y chromosomes differentiate into fertile oocytes? Asian J Androl 2016; 17:360-6. [PMID: 25578929 PMCID: PMC4430933 DOI: 10.4103/1008-682x.143306] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions.
Collapse
Affiliation(s)
- Teruko Taketo
- Department of Surgery, Research Institute of MUHC; Department of Biology; Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
10
|
Cisternas CD, Tome K, Caeiro XE, Dadam FM, Garcia-Segura LM, Cambiasso MJ. Sex chromosome complement determines sex differences in aromatase expression and regulation in the stria terminalis and anterior amygdala of the developing mouse brain. Mol Cell Endocrinol 2015; 414:99-110. [PMID: 26231585 DOI: 10.1016/j.mce.2015.07.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/24/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
Abstract
Aromatase, which converts testosterone in estradiol, is involved in the generation of brain sex dimorphisms. Here we used the "four core genotypes" mouse model, in which the effect of gonadal sex and sex chromosome complement is dissociated, to determine if sex chromosomes influence the expression of brain aromatase. The brain of 16 days old XY mouse embryos showed higher aromatase expression in the stria terminalis and the anterior amygdaloid area than the brain of XX embryos, independent of gonadal sex. Furthermore, estradiol or dihydrotestosterone increased aromatase expression in cultures of anterior amygdala neurons derived from XX embryos, but not in those derived from XY embryos. This effect was also independent of gonadal sex. The expression of other steroidogenic molecules, estrogen receptor-α and androgen receptor was not influenced by sex chromosomes. In conclusion, sex chromosomes determine sex dimorphisms in aromatase expression and regulation in the developing mouse brain.
Collapse
Affiliation(s)
- Carla D Cisternas
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Karina Tome
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Ximena E Caeiro
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Florencia M Dadam
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | | | - María J Cambiasso
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba, Córdoba, Argentina.
| |
Collapse
|
11
|
Palacios-Gimenez OM, Marti DA, Cabral-de-Mello DC. Neo-sex chromosomes of Ronderosia bergi: insight into the evolution of sex chromosomes in grasshoppers. Chromosoma 2015; 124:353-65. [DOI: 10.1007/s00412-015-0505-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 12/27/2014] [Accepted: 01/05/2015] [Indexed: 10/24/2022]
|
12
|
Scerbo MJ, Freire-Regatillo A, Cisternas CD, Brunotto M, Arevalo MA, Garcia-Segura LM, Cambiasso MJ. Neurogenin 3 mediates sex chromosome effects on the generation of sex differences in hypothalamic neuronal development. Front Cell Neurosci 2014; 8:188. [PMID: 25071448 PMCID: PMC4086225 DOI: 10.3389/fncel.2014.00188] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/19/2014] [Indexed: 01/01/2023] Open
Abstract
The organizational action of testosterone during critical periods of development is the cause of numerous sex differences in the brain. However, sex differences in neuritogenesis have been detected in primary neuronal hypothalamic cultures prepared before the peak of testosterone production by fetal testis. In the present study we assessed the hypothesis of that cell-autonomous action of sex chromosomes can differentially regulate the expression of the neuritogenic gene neurogenin 3 (Ngn3) in male and female hypothalamic neurons, generating sex differences in neuronal development. Neuronal cultures were prepared from male and female E14 mouse hypothalami, before the fetal peak of testosterone. Female neurons showed enhanced neuritogenesis and higher expression of Ngn3 than male neurons. The silencing of Ngn3 abolished sex differences in neuritogenesis, decreasing the differentiation of female neurons. The sex difference in Ngn3 expression was determined by sex chromosomes, as demonstrated using the four core genotypes mouse model, in which a spontaneous deletion of the testis-determining gene Sry from the Y chromosome was combined with the insertion of the Sry gene onto an autosome. In addition, the expression of Ngn3, which is also known to mediate the neuritogenic actions of estradiol, was increased in the cultures treated with the hormone, but only in those from male embryos. Furthermore, the hormone reversed the sex differences in neuritogenesis promoting the differentiation of male neurons. These findings indicate that Ngn3 mediates both cell-autonomous actions of sex chromosomes and hormonal effects on neuritogenesis.
Collapse
Affiliation(s)
- María J Scerbo
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET - Universidad Nacional de Córdoba Córdoba, Argentina
| | | | - Carla D Cisternas
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET - Universidad Nacional de Córdoba Córdoba, Argentina ; Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba Córdoba, Argentina
| | - Mabel Brunotto
- Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba Córdoba, Argentina
| | - Maria A Arevalo
- Instituto Cajal, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | | | - María J Cambiasso
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET - Universidad Nacional de Córdoba Córdoba, Argentina ; Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba Córdoba, Argentina
| |
Collapse
|
13
|
Identification of sexually dimorphic genes in the neonatal mouse cortex and hippocampus. Brain Res 2014; 1562:23-38. [PMID: 24661915 DOI: 10.1016/j.brainres.2014.03.017] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 03/08/2014] [Accepted: 03/15/2014] [Indexed: 01/01/2023]
Abstract
The cerebral cortex and hippocampus are important for the control of cognitive functions and social behaviors, many of which are sexually dimorphic and tightly regulated by gonadal steroid hormones via activation of their respective nuclear receptors. As different levels of sex steroid hormones are present between the sexes during early development and their receptors act as transcription factors to regulate gene expression, we hypothesize that sexually dimorphic gene expression in the developing mouse cortex and hippocampus might result in sex differences in brain structures and neural circuits governing distinct behaviors between the sexes as adults. To test our hypothesis, we used gene expression microarrays to identify 90 candidate genes differentially expressed in the neonatal cortex/hippocampus between male and female mice, including 55 male-biased and 35 female-biased genes. Among these genes, sexually dimorphic expression of eight sex chromosome genes was confirmed by reverse transcription with quantitative PCR (RT-qPCR), including three located on the X chromosome (Xist, Eif2s3x, and Kdm6a), three on the Y chromosome (Ddx3y, Eif2s3y, and Kdm5d), and two in the pseudoautosomal region of the X and Y chromosomes (Erdr1 and Mid1). In addition, five autosomal genes (Cd151, Dab2, Klk8, Meg3, and Prkdc) were also validated for their sexually dimorphic expression in the neonatal mouse cortex/hippocampus. Gene Ontology annotation analysis suggests that many of these sexually dimorphic genes are involved in histone modifications, cell proliferation/death, androgen/estrogen signaling pathways, and synaptic organization, and these biological processes have been implicated in differential neural development, cognitive function, and neurological diseases between the sexes.
Collapse
|
14
|
Taketo T, Naumova AK. Oocyte heterogeneity with respect to the meiotic silencing of unsynapsed X chromosomes in the XY female mouse. Chromosoma 2013; 122:337-49. [DOI: 10.1007/s00412-013-0415-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 03/26/2013] [Accepted: 05/13/2013] [Indexed: 12/16/2022]
|
15
|
Evans EB, Hogarth C, Evanoff RM, Mitchell D, Small C, Griswold MD. Localization and regulation of murine Esco2 during male and female meiosis. Biol Reprod 2012; 87:61. [PMID: 22699483 DOI: 10.1095/biolreprod.112.099978] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Meiosis is essential for generation of healthy gametes in both sexes and involves recombination and segregation of homologous chromosomes to produce haploid gametes. The initiation of meiosis in both sexes relies upon retinoic acid (RA) (Griswold MD, Hogarth CA, Bowles J, Koopman P. Initiating Meiosis: The Case for Retinoic Acid. Biol Reprod 2012; 86(35):1-7). Previous studies have demonstrated that the stimulated by retinoic acid gene 8 (Stra8) was required for meiotic progression in both the mouse ovary and postnatal testis. To identify additional candidates that may play a role during meiosis, we used microarray databases to generate lists of transcripts with expression profiles similar to that of Stra8 in the embryonic ovary and postnatal testis. One such gene, establishment of cohesion 1 homolog 2 (Saccharomyces cerevisiae) (Esco2), has been described as a regulator of sister chromatid cohesion during mitosis. This study describes the first in-depth analysis of ESCO2 localization and regulation during meiosis in both males and females. ESCO2 colocalized with the gamma H2A histone family member X (H2AFX) in pachytene spermatocytes, indicating that ESCO2 is a component of the XY body. In pachytene cells of the embryonic ovary, ESCO2 colocalized with H2AFX, which is consistent with the presence of ESCO2 in areas of double-stranded breaks. In addition, the expression of Esco2 was found to be regulated by RA in the postnatal testis. These data indicate that ESCO2 may play a vital role in meiosis in both males and females.
Collapse
Affiliation(s)
- Elizabeth B Evans
- School of Molecular Biosciences and The Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
| | | | | | | | | | | |
Collapse
|
16
|
The presence of the Y-chromosome, not the absence of the second X-chromosome, alters the mRNA levels stored in the fully grown XY mouse oocyte. PLoS One 2012; 7:e40481. [PMID: 22792347 PMCID: PMC3391287 DOI: 10.1371/journal.pone.0040481] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 06/08/2012] [Indexed: 12/23/2022] Open
Abstract
The oocytes of B6.YTIR sex-reversed female mouse mature in culture but fail to develop after fertilization because of their cytoplasmic defects. To identify the defective components, we compared the gene expression profiles between the fully-grown oocytes of B6.YTIR (XY) females and those of their XX littermates by cDNA microarray. 173 genes were found to be higher and 485 genes were lower in XY oocytes than in XX oocytes by at least 2-fold. We compared the transcript levels of selected genes by RT-PCR in XY and XX oocytes, as well as in XO oocytes missing paternal X-chromosomes. All genes tested showed comparable transcript levels between XX and XO oocytes, indicating that mRNA accumulation is well adjusted in XO oocytes. By contrast, in addition to Y-encoded genes, many genes showed significantly different transcript levels in XY oocytes. We speculate that the presence of the Y-chromosome, rather than the absence of the second X-chromosome, caused dramatic changes in the gene expression profile in the XY fully-grown oocyte.
Collapse
|
17
|
Page J, de la Fuente R, Manterola M, Parra MT, Viera A, Berríos S, Fernández-Donoso R, Rufas JS. Inactivation or non-reactivation: what accounts better for the silence of sex chromosomes during mammalian male meiosis? Chromosoma 2012; 121:307-26. [PMID: 22366883 DOI: 10.1007/s00412-012-0364-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 02/08/2012] [Accepted: 02/09/2012] [Indexed: 12/28/2022]
Abstract
During the first meiotic prophase in male mammals, sex chromosomes undergo a program of transcriptional silencing called meiotic sex chromosome inactivation (MSCI). MSCI is triggered by accumulation of proteins like BRCA1, ATR, and γH2AX on unsynapsed chromosomes, followed by local changes on the sex chromatin, including histone modifications, incorporation of specific histone variants, non-histone proteins, and RNAs. It is generally thought that MSCI represents the transition of unsynapsed chromatin from a transcriptionally active state to a repressed state. However, transcription is generally low in the whole nucleus during the early stages of the first meiotic prophase, when markers of MSCI first appear, and is then reactivated globally during pachytene. Thus, an alternative possibility is that MSCI represents the targeted maintenance and/or reinforcement of a prior repressed state, i.e., a failure to reactivate. Here, we present an analysis of the temporal and spatial appearance of transcriptional and MSCI markers, as well as chromatin modifications related to transcriptional regulation. We show that levels of RNA pol II and histone H3 acetylated at lysine 9 (H3K9ac) are low during leptotene, zygotene, and early pachytene, but increase strongly in mid-pachytene, indicating that reactivation occurs with some delay after synapsis. However, while transcription markers appear abundantly on the autosomes at mid-pachytene, they are not directed to the sex chromosomes. Interestingly, we found that chromatin modifications related to transcriptional silencing and/or MSCI, namely, histone H3 trimethylated at lysine 9 (H3K9me3), histone H3 monomethylated at lysine 4 (H3K4me1), γH2AX, SUMO1, and XMR, appear on the sex chromosomes before autosomes become reactivated. These results suggest that the onset of MSCI during late zygotene and early pachytene may prevent sex chromosome reactivation during mid-pachytene instead of promoting inactivation de novo. Additionally, we found temporal differences between the X and Y chromosomes in the recruitment of DNA repair and MSCI markers, indicating a differential regulation of these processes. We propose that many of the meiotic defects attributed to failure to silence sex chromosomes could be interpreted as a more general process of transcriptional misregulation that occurs under certain pathological circumstances in zygotene and early pachytene.
Collapse
Affiliation(s)
- Jesús Page
- Unidad de Biología Celular, Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Wijchers PJ, Yandim C, Panousopoulou E, Ahmad M, Harker N, Saveliev A, Burgoyne PS, Festenstein R. Sexual Dimorphism in Mammalian Autosomal Gene Regulation Is Determined Not Only by Sry but by Sex Chromosome Complement As Well. Dev Cell 2010; 19:477-84. [DOI: 10.1016/j.devcel.2010.08.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 03/18/2010] [Accepted: 07/16/2010] [Indexed: 10/19/2022]
|
19
|
Vaskova EA, Pavlova SV, Shevchenko AI, Zakian SM. Meiotic inactivation of sex chromosomes in mammals. RUSS J GENET+ 2010. [DOI: 10.1134/s1022795410040010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
20
|
Tsai HW, Grant PA, Rissman EF. Sex differences in histone modifications in the neonatal mouse brain. Epigenetics 2009; 4:47-53. [PMID: 19029819 DOI: 10.4161/epi.4.1.7288] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Sex differences in neural development are established via a number of cellular processes (i.e., migration, death and survival). One critical factor identified is the neonatal rise in testosterone (T) which activates gene transcription via androgen (AR) and, after aromatization to estradiol, estrogen receptors (ERalpha and beta). Recent evidence shows that AR and ERs interact with histone modifying enzymes. Post-translational modifications of histones, including acetylation and methylation, are involved in transcriptional regulation during normal development. Therefore, we hypothesized that acetylation and/or methylation of histone H3 may underlie sexual differentiation, at least in some regions of the brain. We measured levels of acetylated (H3K9/14Ac) and trimethylated (H3K9Me3) H3 in whole neonatal mouse brains and in three regions: preoptic area + hypothalamus, amygdala and cortex + hippocampus (CTX/HIP). Sex differences in H3K9/14Ac and H3K9Me3 (males > females) were noted in the CTX/HIP on embryonic day 18, the day of birth, and six days later. To determine if T mediates these changes in H3 modifications, pregnant dams received vehicle or T for the final four days of gestation; pup brains were collected at birth. Methylation of H3 was sexually dimorphic despite hormone treatment. In contrast, H3 acetylation in the CTX/HIP of females from T-treated dams rose to levels equivalent to males. Thus, H3 modifications are sexually dimorphic in the developing mouse CTX/HIP and acetylation, but not methylation, is masculinized in females by T in utero. This is the first demonstration that histone modification is associated with neural sexual differentiation.
Collapse
Affiliation(s)
- Houng-Wei Tsai
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, 22908, USA
| | | | | |
Collapse
|
21
|
McPhie-Lalmansingh AA, Tejada LD, Weaver JL, Rissman EF. Sex chromosome complement affects social interactions in mice. Horm Behav 2008; 54:565-70. [PMID: 18590732 PMCID: PMC2561329 DOI: 10.1016/j.yhbeh.2008.05.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/21/2008] [Accepted: 05/27/2008] [Indexed: 12/12/2022]
Abstract
Sex differences in behavior can be attributed to differences in steroid hormones. Sex chromosome complement can also influence behavior, independent of gonadal differentiation. The mice used for this work combined a spontaneous mutation of the Sry gene with a transgene for Sry that is incorporated into an autosome thus disassociating gonad differentiation from sex chromosome complement. The resulting genotypes are XX and XY(-) females (ovary-bearing) along with XXSry and XY(-)Sry males (testes-bearing). Here we report results of basic behavioral phenotyping conducted with these mice. Motor coordination, use of olfactory cues to find a food item, general activity, foot shock threshold, and behavior in an elevated plus maze were not affected by gonadal sex or sex chromosome complement. In a one-way active avoidance learning task females were faster to escape an electric shock than males. In addition, sex chromosome complement differences were noted during social interactions with submissive intruders. Female XY(-) mice were faster to follow an intruder than XX female mice. All XY(-) mice spent more time sniffing and grooming the intruder than the XX mice, with XY(-) females spending the most amount of time in this activity. Finally, XX females were faster to display an asocial behavior, digging, and engaged in more digging than XXSry male mice. All of these behaviors were tested in gonadectomized adults, thus, differences in circulating levels of gonadal steroids cannot account for these effects. Taken together, these data show that sex chromosome complement affects social interaction style in mice.
Collapse
Affiliation(s)
| | | | | | - Emilie F. Rissman
- Corresponding author. PO Box 800733, Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Fax: +1 434 243 8433. E-mail address: (E.F. Rissman)
| |
Collapse
|
22
|
Noguchi J, Ozawa M, Nakai M, Somfai T, Kikuchi K, Kaneko H, Kunieda T. Affected homologous chromosome pairing and phosphorylation of testis specific histone, H2AX, in male meiosis under FKBP6 deficiency. J Reprod Dev 2008; 54:203-7. [PMID: 18408354 DOI: 10.1262/jrd.19158] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A gene for FK506 binding protein 6 (Fkbp6) expresses during a specific stage of male and female meiosis. Disruption of the gene influences male reproduction, i.e. arrests spermatogenesis, but not female reproduction. Using the mouse model (targeted disruption), the role of the gene in homologous chromosome pairing has been demonstrated in a previous study. For further understanding the function of Fkbp6 in chromosome synapsis, we evaluated chromosome pairings during male meiosis in the as/as rat, a spontaneous null mutation, and compared them with those of the mouse model. Electron microscopy of the pachytene nuclei unveiled several types of abnormal chromosome pairing in the rat model, as shown in the mouse previously. The frequencies of aberrant pairings in the knockout mice and mutant rats were 42 of 67 nuclei (62.7%) and 20 out of 74 nuclei (27.0%), respectively. In order to clarify the mechanism of male specific infertility in Fkbp6 deficiency, the localization of gammaH2AX, a marker protein of XY chromosome inactivation during male meiosis, was examined. Immunostaining of gammaH2AX unveiled normal localization of the molecule to XY chromosomes (XY body) in both models, showing the independency of FKBP6 in sex chromosome inactivation. Besides the XY body, focal localization of gammaH2AX was observed in accordance with the unsynapsed chromosomes in both types of null animal. These results indicate the fundamental role of Fkbp6 in homologous chromosome synapsis during male meiosis. In conclusion, male specific infertility under Fkbp6 deficiency remains unsolved.
Collapse
Affiliation(s)
- Junko Noguchi
- Reproductive Biology Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Japan.
| | | | | | | | | | | | | |
Collapse
|
23
|
Alton M, Lau MP, Villemure M, Taketo T. The behavior of the X- and Y-chromosomes in the oocyte during meiotic prophase in the B6.YTIR sex-reversed mouse ovary. Reproduction 2008; 135:241-52. [DOI: 10.1530/rep-07-0383] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Sexual differentiation of the germ cells follows gonadal differentiation, which is determined by the presence or the absence of the Y-chromosome. Consequently, oogenesis and spermatogenesis take place in the germ cells with XX and XY sex chromosomal compositions respectively. It is unclear how sexual dimorphic regulation of meiosis is associated with the sex-chromosomal composition. In the present study, we examined the behavior of the sex chromosomes in the oocytes of the B6.YTIRsex-reversed female mouse, in comparison with XO and XX females. As the sex chromosomes fail to pair in both XY and XO oocytes during meiotic prophase, we anticipated that the pairing failure may lead to excessive oocyte loss. However, the total number of germ cells, identified by immunolabeling of germ cell nuclear antigen 1 (GCNA1), did not differ between XY and XX ovaries or XO and XX ovaries up to the day of delivery. The progression of meiotic prophase, assessed by immunolabeling of synaptonemal complex components, was also similar between the two genotypes of ovaries. These observations suggest that the failure in sex-chromosome pairing is not sufficient to cause oocyte loss. On the other hand, labeling of phosphorylated histone γH2AX, known to be associated with asynapsis and transcriptional repression, was seen over the X-chromosome but not over the Y-chromosome in the majority of XY oocytes at the pachytene stage. For comparison, γH2AX labeling was seen only in the minority of XX oocytes at the same stage. We speculate that the transcriptional activity of sex chromosomes in the XY oocyte may be incompatible with ooplasmic maturation.
Collapse
|
24
|
Takada Y, Isono KI, Shinga J, Turner JMA, Kitamura H, Ohara O, Watanabe G, Singh PB, Kamijo T, Jenuwein T, Burgoyne PS, Koseki H. Mammalian Polycomb Scmh1 mediates exclusion of Polycomb complexes from the XY body in the pachytene spermatocytes. Development 2007; 134:579-90. [PMID: 17215307 DOI: 10.1242/dev.02747] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The product of the Scmh1 gene, a mammalian homolog of Drosophila Sex comb on midleg, is a constituent of the mammalian Polycomb repressive complexes 1 (Prc1). We have identified Scmh1 as an indispensable component of the Prc1. During progression through pachytene, Scmh1 was shown to be excluded from the XY body at late pachytene, together with other Prc1 components such as Phc1, Phc2, Rnf110 (Pcgf2), Bmi1 and Cbx2. We have identified the role of Scmh1 in mediating the survival of late pachytene spermatocytes. Apoptotic elimination of Scmh1(-/-) spermatocytes is accompanied by the preceding failure of several specific chromatin modifications at the XY body, whereas synapsis of homologous autosomes is not affected. It is therefore suggested that Scmh1 is involved in regulating the sequential changes in chromatin modifications at the XY chromatin domain of the pachytene spermatocytes. Restoration of defects in Scmh1(-/-) spermatocytes by Phc2 mutation indicates that Scmh1 exerts its molecular functions via its interaction with Prc1. Therefore, for the first time, we are able to indicate a functional involvement of Prc1 during the meiotic prophase of male germ cells and a regulatory role of Scmh1 for Prc1, which involves sex chromosomes.
Collapse
Affiliation(s)
- Yuki Takada
- RIKEN Research Center for Allergy and Immunology, 1-7-22 Suehiro, Yokohama, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Yogev L, Zeharia E, Kleiman SE, Maymon BB, Hauser R, Botchan A, Yavetz H, Paz G. Use of sex chromosome bivalent pairing in spermatocytes of nonobstructive azoospermic men for the prediction of successful sperm retrieval. Fertil Steril 2006; 86:106-12. [PMID: 16818033 DOI: 10.1016/j.fertnstert.2005.11.072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 11/28/2005] [Accepted: 11/28/2005] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To find the most informative method of XY bivalent detection for spermatozoa presence in testicular tissue of nonobstructive azoospermic men. DESIGN Prospective study. SETTING Institute for the Study of Fertility, affiliated with a university medical faculty. PATIENT(S) Thirty-five men with azoospermia, divided into subgroups: complete maturation arrest (n = 10), mixed atrophy (n = 14), and obstructive azoospermia (n = 11). INTERVENTION(S) Testicular tissue biopsies for sperm extraction. MAIN OUTCOME MEASURE(S) Histopathologic and cytology analyses and the presence of XY bivalent formation by fluorescence in situ hybridization probes for centromere and subtelomere regions. Immunostaining of gamma-H2AX for sex body (SB) identification was also performed. RESULT(S) Percentage of spermatocytes with X-Y pairing, determined by the paired short arms pseudoautosomal region, was significantly higher than percentage of spermatocytes with long arm telomeres in proximity in all three groups. The parameter of q telomeres in proximity was the most sensitive index to distinguish one group from the other. Stained SB by gamma-H2AX was found to be the most informative for the prediction of successful sperm retrieval. CONCLUSION(S) Alignment of the X and Y axes that occurs in the late zygotene stage probably precedes the stage in which the SB is stained by gamma-H2AX. Consequently, because of the nonhomogeneity of the testis, when histology raises suspicion of complete maturation arrest percentage of spermatocytes with stained SB is the most informative parameter for sperm presence on sperm retrieval.
Collapse
Affiliation(s)
- Leah Yogev
- Institute for the Study of Fertility, Lis Maternity Hospital, Tel Aviv University, Ramat Aviv, Israel.
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
Mammalian sex chromosomes are highly diverged and heteromorphic: a comparatively large and gene-rich X chromosome contrasting with a small, largely heterochromatic and degenerate Y chromosome. Both gonosomes are however uniquely important in male-specific functions such as spermatogenesis. In this review, we examine the evolutionary pressures that have driven the divergence of the sex chromosomes from their ancestral state, and show how these have shaped the gene content of both chromosomes. Their shared history of gene acquisition and loss, differentiation, degeneration and intragenomic warfare has far-reaching consequences for their functionality in spermatogenesis, and may also have potential clinical implications.
Collapse
|
27
|
Costa Y, Speed RM, Gautier P, Semple CA, Maratou K, Turner JMA, Cooke HJ. Mouse MAELSTROM: the link between meiotic silencing of unsynapsed chromatin and microRNA pathway? Hum Mol Genet 2006; 15:2324-34. [PMID: 16787967 DOI: 10.1093/hmg/ddl158] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Meiotic silencing of unsynapsed chromatin (MSUC) is a key mechanism in spermatogenesis and a model system to study the dynamics of gene silencing. Here we show that MAEL, the ortholog of Drosophila's high mobility group box protein Maelstrom, is associated not only with the silenced XY body, but also with unsynapsed autosomes. Characterization of MAEL revealed that it interacts directly with the chromatin remodeler SNF5/INI1 and chromatin-associated protein SIN3B, which we also find localized to the XY body. This is the first time that a chromatin remodeler has been shown to associate with whole chromosomes. In addition, we show that MAEL is a component of the mouse meiotic nuage and its haploid cell counterpart, the chromatoid body. This is a site of accumulation of RNA and RNA processing enzymes, including proteins involved in the microRNA (miRNA) pathway. Furthermore, in the nuage, MAEL is present in a complex with germ cell specific MVH, an RNA helicase and Argonaute family members, MILI and MIWI. The presence of MAEL in these critical compartments of male germ cells and its interactions provide a link suggesting the involvement of the miRNA pathway in MSUC.
Collapse
Affiliation(s)
- Yael Costa
- MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | | | | | | | | | | | | |
Collapse
|
28
|
Gatewood JD, Wills A, Shetty S, Xu J, Arnold AP, Burgoyne PS, Rissman EF. Sex chromosome complement and gonadal sex influence aggressive and parental behaviors in mice. J Neurosci 2006; 26:2335-42. [PMID: 16495461 PMCID: PMC6674813 DOI: 10.1523/jneurosci.3743-05.2006] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Across human cultures and mammalian species, sex differences can be found in the expression of aggression and parental nurturing behaviors: males are typically more aggressive and less parental than females. These sex differences are primarily attributed to steroid hormone differences during development and/or adulthood, especially the higher levels of androgens experienced by males, which are caused ultimately by the presence of the testis-determining gene Sry on the Y chromosome. The potential for sex differences arising from the different complements of sex-linked genes in male and female cells has received little research attention. To directly test the hypothesis that social behaviors are influenced by differences in sex chromosome complement other than Sry, we used a transgenic mouse model in which gonadal sex and sex chromosome complement are uncoupled. We find that latency to exhibit aggression and one form of parental behavior, pup retrieval, can be influenced by both gonadal sex and sex chromosome complement. For both behaviors, females but not males with XX sex chromosomes differ from XY. We also measured vasopressin immunoreactivity in the lateral septum, which was higher in gonadal males than females, but also differed according to sex chromosome complement. These results imply that a gene(s) on the sex chromosomes (other than Sry) affects sex differences in brain and behavior. Identifying the specific X and/or Y genes involved will increase our understanding of normal and abnormal aggression and parental behavior, including behavioral abnormalities associated with mental illness.
Collapse
|
29
|
Vigodner M, Morris PL. Testicular expression of small ubiquitin-related modifier-1 (SUMO-1) supports multiple roles in spermatogenesis: silencing of sex chromosomes in spermatocytes, spermatid microtubule nucleation, and nuclear reshaping. Dev Biol 2005; 282:480-92. [PMID: 15950612 DOI: 10.1016/j.ydbio.2005.03.034] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Revised: 03/01/2005] [Accepted: 03/27/2005] [Indexed: 12/25/2022]
Abstract
SUMO-1 is a member of a ubiquitin-related family of proteins that mediates important post-translational effects affecting diverse physiological functions. Whereas SUMO-1 is detected in the testis, little is known about its reproductive role in males. Herein, cell-specific SUMO-1 was localized in freshly isolated, purified male germ cells and somatic cells of mouse and rat testes using Western analysis, high-resolution single-cell bioimaging, and in situ confocal microscopy of seminiferous tubules. During germ cell development, SUMO-1 was observed at low but detectable levels in the cytoplasm of spermatogonia and early spermatocytes. SUMO-1 appeared on gonosomal chromatin during zygotene when chromosome homologues pair and sex chromatin condensation is initiated. Striking SUMO-1 increases in the sex body of early-to-mid-pachytene spermatocytes correlated with timing of additional sex chromosome condensation. Before the completion of the first meiotic division, SUMO-1 disappeared from the sex body when X and Y chromosomal activity resumed. Together, these data indicate that sumoylation may be involved in non-homologous chromosomal synapsis, meiotic sex chromosome inactivation, and XY body formation. During spermiogenesis, SUMO-1 localized in chromocenters of certain round spermatids and perinuclear ring and centrosomes of elongating spermatids, data implicating SUMO-1 in the process of microtubule nucleation and nuclear reshaping. STAT-4, one potential target of sumoylation, was located along the spermatid nuclei, adjacent but not co-localized with SUMO-1. Androgen receptor-positive Leydig, Sertoli, and some peritubular myoepithelial cells express SUMO-1, findings suggesting a role in modulating steroid action. Testicular SUMO-1 expression supports its specific functions in inactivation of sex chromosomes during meiosis, spermatid microtubule nucleation, nuclear reshaping, and gene expression.
Collapse
Affiliation(s)
- Margarita Vigodner
- Center for Biomedical Research, Population Council, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
| | | |
Collapse
|
30
|
Pauls K, Franke FE, Büttner R, Zhou H. Gonadoblastoma: evidence for a stepwise progression to dysgerminoma in a dysgenetic ovary. Virchows Arch 2005; 447:603-9. [PMID: 15968543 DOI: 10.1007/s00428-005-1272-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Accepted: 04/12/2005] [Indexed: 11/30/2022]
Abstract
Gonadoblastomas are neoplasms of dysgenetic gonads which may undergo regression or become overgrown by malignant germ cell tumors (mGCTs). Since little is known about their relationship to normal gonadal development and mGCTs, we studied the phenotype and antigenic profile of gonadoblastomas in comparison with adjacent dysgerminomas and fetal gonads. Three cases of gonadoblastomas and fetal gonads of both sexes were analyzed using oncofetal markers to M2A-antigen (M2A), germ cell alkaline phosphatase (PLAP/GCAP), receptor tyrosine kinase c-kit (c-kit), and somatic angiotensin converting enzyme (sACE) as well as the proliferation marker MIB-1. Morphologically, microfollicular pattern of gonadoblastomas showed a fetal germ cell organization reminiscent of oocytic clusters of fetal ovaries. They contained both cell types, similar to oocytes (M2A-, GCAP-, c-kit+/-, sACE-) and oogonia (M2A+, GCAP+, c-kit+, sACE+). The percentage of germ cells immunoreactive for oncofetal markers and the proliferation index increased from microfollicular over coronary patterns to adjacent dysgerminomas. Supportive cells of gonadoblastomas showed a uniform phenotype (CK18+, vimentin+, sACE+, alpha-inhibin+, M2A-) but in contrast to fetal germ cells lacked a clear equivalence to fetal tissues. Our results show that gonadoblastomas mimic female fetal ovary and exhibit a stepwise progression from follicular pattern to coronary pattern and finally to dysgerminomas.
Collapse
|
31
|
Baarends WM, Wassenaar E, van der Laan R, Hoogerbrugge J, Sleddens-Linkels E, Hoeijmakers JHJ, de Boer P, Grootegoed JA. Silencing of unpaired chromatin and histone H2A ubiquitination in mammalian meiosis. Mol Cell Biol 2005; 25:1041-53. [PMID: 15657431 PMCID: PMC543997 DOI: 10.1128/mcb.25.3.1041-1053.2005] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During meiotic prophase in male mammals, the X and Y chromosomes are incorporated in the XY body. This heterochromatic body is transcriptionally silenced and marked by increased ubiquitination of histone H2A. This led us to investigate the relationship between histone H2A ubiquitination and chromatin silencing in more detail. First, we found that ubiquitinated H2A also marks the silenced X chromosome of the Barr body in female somatic cells. Next, we studied a possible relationship between H2A ubiquitination, chromatin silencing, and unpaired chromatin in meiotic prophase. The mouse models used carry an unpaired autosomal region in male meiosis or unpaired X and Y chromosomes in female meiosis. We show that ubiquitinated histone H2A is associated with transcriptional silencing of large chromatin regions. This silencing in mammalian meiotic prophase cells concerns unpaired chromatin regions and resembles a phenomenon described for the fungus Neurospora crassa and named meiotic silencing by unpaired DNA.
Collapse
Affiliation(s)
- Willy M Baarends
- Department of Reproduction and Development, Erasmus MC, University Medical Center Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Silencing of unsynapsed meiotic chromosomes in the mouse. Nat Genet 2004; 37:41-7. [PMID: 15580272 DOI: 10.1038/ng1484] [Citation(s) in RCA: 415] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Accepted: 11/11/2004] [Indexed: 12/12/2022]
Abstract
In Neurospora, DNA unpaired in meiosis both is silenced and induces silencing of all DNA homologous to it. This process, called meiotic silencing by unpaired DNA, is thought to protect the host genome from invasion by transposable elements. We now show that silencing of unpaired (unsynapsed) chromosome regions also takes place in the mouse during both male and female meiosis. The tumor suppressor protein BRCA1 is implicated in this silencing, mirroring its role in the meiotic silencing of the X and Y chromosomes in normal male meiosis. These findings impact on the interpretation of the relationship between synaptic errors and sterility in mammals and extend our understanding of the biology of Brca1.
Collapse
|
33
|
Touré A, Szot M, Mahadevaiah SK, Rattigan A, Ojarikre OA, Burgoyne PS. A new deletion of the mouse Y chromosome long arm associated with the loss of Ssty expression, abnormal sperm development and sterility. Genetics 2004; 166:901-12. [PMID: 15020475 PMCID: PMC1470733 DOI: 10.1534/genetics.166.2.901] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mouse Y chromosome carries 10 distinct genes or gene families that have open reading frames suggestive of retained functionality; it has been assumed that many of these function in spermatogenesis. However, we have recently shown that only two Y genes, the testis determinant Sry and the translation initiation factor Eif2s3y, are essential for spermatogenesis to proceed to the round spermatid stage. Thus, any further substantive mouse Y-gene functions in spermatogenesis are likely to be during sperm differentiation. The complex Ssty gene family present on the mouse Y long arm (Yq) has been implicated in sperm development, with partial Yq deletions that reduce Ssty expression resulting in impaired fertilization efficiency. Here we report the identification of a more extensive Yq deletion that abolishes Ssty expression and results in severe sperm defects and sterility. This result establishes that genetic information (Ssty?) essential for normal sperm differentiation and function is present on mouse Yq.
Collapse
Affiliation(s)
- Aminata Touré
- National Institute for Medical Research, London NW7 1AA, UK
| | | | | | | | | | | |
Collapse
|
34
|
van der Laan R, Uringa EJ, Wassenaar E, Hoogerbrugge JW, Sleddens E, Odijk H, Roest HP, de Boer P, Hoeijmakers JHJ, Grootegoed JA, Baarends WM. Ubiquitin ligase Rad18Sc localizes to the XY body and to other chromosomal regions that are unpaired and transcriptionally silenced during male meiotic prophase. J Cell Sci 2004; 117:5023-33. [PMID: 15383616 DOI: 10.1242/jcs.01368] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In replicative damage bypass (RDB) in yeast, the ubiquitinconjugating enzyme RAD6 interacts with the ubiquitin ligase RAD18. In the mouse, these enzymes are represented by two homologs of RAD6, HR6a and HR6b, and one homolog of RAD18, Rad18Sc. Expression of these genes and the encoded proteins is ubiquitous, but there is relatively high expression in the testis. We have studied the subcellular localization by immunostaining Rad18Sc and other RDB proteins in mouse primary spermatocytes passing through meiotic prophase in spermatogenesis. The highest Rad18Sc protein level is found at pachytene and diplotene, and the protein localizes mainly to the XY body, a subnuclear region that contains the transcriptionally inactivated X and Y chromosomes. In spermatocytes that carry translocations for chromosomes 1 and 13, Rad18Sc protein concentrates on translocation bivalents that are not fully synapsed. The partly synapsed bivalents are often localized in the vicinity of the XY body, and show a very low level of RNA polymerase II, indicating that the chromatin is in a silent configuration similar to transcriptional silencing of the XY body. Thus, Rad18Sc localizes to unsynapsed and silenced chromosome segments during the male meiotic prophase. All known functions of RAD18 in yeast are related to RDB. However, in contrast to Rad18Sc, expression of UBC13 and polη, known to be involved in subsequent steps of RDB, appears to be diminished in the XY body and regions containing the unpaired translocation bivalents. Taken together, these observations suggest that the observed subnuclear localization of Rad18Sc may involve a function outside the context of RDB. This function is probably related to a mechanism that signals the presence of unsynapsed chromosomal regions and subsequently leads to transcriptional silencing of these regions during male meiotic prophase.
Collapse
Affiliation(s)
- Roald van der Laan
- MGC-Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, University Medical Center, PO Box 1738, 3000 DR Rotterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Touré A, Szot M, Mahadevaiah SK, Rattigan Á, Ojarikre OA, Burgoyne PS. A New Deletion of the Mouse Y Chromosome Long Arm Associated With the Loss of Ssty Expression, Abnormal Sperm Development and Sterility. Genetics 2004. [DOI: 10.1093/genetics/166.2.901] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Abstract
The mouse Y chromosome carries 10 distinct genes or gene families that have open reading frames suggestive of retained functionality; it has been assumed that many of these function in spermatogenesis. However, we have recently shown that only two Y genes, the testis determinant Sry and the translation initiation factor Eif2s3y, are essential for spermatogenesis to proceed to the round spermatid stage. Thus, any further substantive mouse Y-gene functions in spermatogenesis are likely to be during sperm differentiation. The complex Ssty gene family present on the mouse Y long arm (Yq) has been implicated in sperm development, with partial Yq deletions that reduce Ssty expression resulting in impaired fertilization efficiency. Here we report the identification of a more extensive Yq deletion that abolishes Ssty expression and results in severe sperm defects and sterility. This result establishes that genetic information (Ssty?) essential for normal sperm differentiation and function is present on mouse Yq.
Collapse
Affiliation(s)
- Aminata Touré
- National Institute for Medical Research, London NW7 1AA, United Kingdom
| | - Maria Szot
- National Institute for Medical Research, London NW7 1AA, United Kingdom
- Department of Genetics and Evolution, Jagiellonian University, 30-060 Krakow, Poland
| | | | - Áine Rattigan
- National Institute for Medical Research, London NW7 1AA, United Kingdom
| | - Obah A Ojarikre
- National Institute for Medical Research, London NW7 1AA, United Kingdom
| | - Paul S Burgoyne
- National Institute for Medical Research, London NW7 1AA, United Kingdom
| |
Collapse
|
36
|
Hoyer-Fender S, Czirr E, Radde R, Turner JMA, Mahadevaiah SK, Pehrson JR, Burgoyne PS. Localisation of histone macroH2A1.2 to the XY-body is not a response to the presence of asynapsed chromosome axes. J Cell Sci 2004; 117:189-98. [PMID: 14676273 DOI: 10.1242/jcs.00851] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Histone macroH2A1.2 and the murine heterochromatin protein 1, HP1β, have both been implicated in meiotic sex chromosome inactivation (MSCI) and the formation of the XY-body in male meiosis. In order to get a closer insight into the function of histone macroH2A1.2 we have investigated the localisation of macroH2A1.2 in surface spread spermatocytes from normal male mice and in oocytes of XX and XYTdym1 mice. Oocytes of XYTdym1 mice have no XY-body or MSCI despite having an XY chromosome constitution, so the presence or absence of `XY-body' proteins in association with the X and/or Y chromosome of these oocytes enables some discrimination between potential functions of XY-body located proteins. We demonstrate here that macroH2A1.2 localises to the X and Y chromatin of spermatocytes as they condense to form the XY-body but is not associated with the X and Y chromatin of XYTdym1 early pachytene oocytes. MacroH2A1.2 and HP1β co-localise to autosomal pericentromeric heterochromatin in spermatocytes. However, the two proteins show temporally and spatially distinct patterns of association to X and Y chromatin.
Collapse
Affiliation(s)
- Sigrid Hoyer-Fender
- III. Department of Zoology-Developmental Biology, University of Göttingen, Humboldtallee 34A, 37073 Göttingen, Germany.
| | | | | | | | | | | | | |
Collapse
|
37
|
Metzler-Guillemain C, Luciani J, Depetris D, Guichaoua MR, Mattei MG. HP1beta and HP1gamma, but not HP1alpha, decorate the entire XY body during human male meiosis. Chromosome Res 2003; 11:73-81. [PMID: 12675308 DOI: 10.1023/a:1022014217196] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
During meiosis in male mammals, the X and Y chromosomes become heterochromatic and transcriptionally silent, and form the XY body. Although the HP1 proteins are known to be involved in the packaging of chromosomal DNA into repressive heterochromatin domains, their involvement in facultative heterochromatinization has not been precisely determined. Here, we analyse, for the first time in humans, the subcellular distribution of the heterochromatin protein HP1alpha, HP1beta and HP1gamma isoforms, in male pachytene spermatocytes, and the XY body facultative heterochromatin in particular. Our results demonstrate that HP1beta and HP1gamma, but not the HP1alpha isoforms, decorate the entire XY body in half the pachytene nuclei observed. In some nuclei, the XY body appears to be only partially labelled. In these cases, the HP1beta and HP1gamma signals are adjacent to the Yq12 constitutive heterochromatin and signal appears to originate in this region before spreading over the entire XY body. This distribution suggests that HP1beta and HP1gamma proteins, which are components of the constitutive heterochromatin, may also be involved in the facultative heterochromatinization of the XY body. Nevertheless, their absence from the early pachytene substage, even though the XY body is already condensed, suggests that these proteins are not involved in the initiation of this process.
Collapse
Affiliation(s)
- C Metzler-Guillemain
- Inserm U491, Faculté de Médecine Timone, 27, Bd Jean Moulin, 13385 Marseille cedex 05, France
| | | | | | | | | |
Collapse
|
38
|
Voet T, Liebe B, Labaere C, Marynen P, Scherthan H. Telomere-independent homologue pairing and checkpoint escape of accessory ring chromosomes in male mouse meiosis. J Cell Biol 2003; 162:795-807. [PMID: 12952934 PMCID: PMC2172825 DOI: 10.1083/jcb.200305065] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We analyzed transmission of a ring minichromosome (MC) through mouse spermatogenesis as a monosome and in the presence of a homologue. Mice, either monosomic or disomic for the MC, produced MC+ offspring. In the monosomic condition, most univalents underwent self-synapsis as indicated by STAG3, SCP3, and SCP1 deposition. Fluorescent in situ hybridization and three-dimensional fluorescence microscopy revealed that ring MCs did not participate in meiotic telomere clustering while MC homologues paired at the XY-body periphery. Self-synapsis of MC(s) and association with the XY-body likely allowed them to pass putative pachytene checkpoints. At metaphase I and II, MC kinetochores assembled MAD2 and BUBR1 spindle checkpoint proteins. Unaligned MCs triggered the spindle checkpoint leading to apoptosis of metaphase cells. Other MCs frequently associated with mouse pericentric heterochromatin, which may have allowed them to pass the spindle checkpoint. Our findings indicate a telomere-independent mechanism for pairing of mammalian MCs, illuminate escape routes to meiotic checkpoints, and give clues for genetic engineering of germ line-permissive chromosomal vectors.
Collapse
Affiliation(s)
- Thierry Voet
- Human Genome Laboratory, Department of Human Genetics, Flanders Interuniversity Institute for Biotechnology, University of Leuven, Belgium
| | | | | | | | | |
Collapse
|
39
|
Ishikawa H, Rattigan A, Fundele R, Burgoyne PS. Effects of sex chromosome dosage on placental size in mice. Biol Reprod 2003; 69:483-8. [PMID: 12700203 DOI: 10.1095/biolreprod.102.012641] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Mice of the XO genotype with a paternally derived X chromosome (XpO) have placental hyperplasia in late pregnancy, although in early pregnancy the ectoplacental cone, a placental precursor, is smaller in XpO mice than in their XX sibs. This early size deficiency of the ectoplacental cone is apparently a consequence of Xp imprinting, because XmO embryos (with a maternally derived X chromosome) are unaffected. In the present study we sought to establish whether XpO placental hyperplasia in late pregnancy is also a consequence of Xp imprinting. Placental weight data were first collected from litters that included XpO or XmO fetuses and XX controls. Comparison of XO placentae with XX placentae showed that XpO and XmO placentae are hyperplastic. This finding suggested that the hyperplasia might be an X dosage effect, and this hypothesis was supported by the finding that XY male fetuses from the same crosses also had larger placentae than their XX sibs. Further analysis of a range of sex-chromosome variant genotypes, including XmYSry-negative females and XXSry transgenic males, showed that mouse fetuses with one X chromosome consistently had larger placentae than littermates with two X chromosomes, independent of their gonadal/androgen status.
Collapse
Affiliation(s)
- Hitoshi Ishikawa
- National Institute for Medical Research, London NW7 1AA, United Kingdom
| | | | | | | |
Collapse
|
40
|
Fernandez-Capetillo O, Mahadevaiah SK, Celeste A, Romanienko PJ, Camerini-Otero RD, Bonner WM, Manova K, Burgoyne P, Nussenzweig A. H2AX is required for chromatin remodeling and inactivation of sex chromosomes in male mouse meiosis. Dev Cell 2003; 4:497-508. [PMID: 12689589 DOI: 10.1016/s1534-5807(03)00093-5] [Citation(s) in RCA: 445] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
During meiotic prophase in male mammals, the X and Y chromosomes condense to form a macrochromatin body, termed the sex, or XY, body, within which X- and Y-linked genes are transcriptionally repressed. The molecular basis and biological function of both sex body formation and meiotic sex chromosome inactivation (MSCI) are unknown. A phosphorylated form of H2AX, a histone H2A variant implicated in DNA repair, accumulates in the sex body in a manner independent of meiotic recombination-associated double-strand breaks. Here we show that the X and Y chromosomes of histone H2AX-deficient spermatocytes fail to condense to form a sex body, do not initiate MSCI, and exhibit severe defects in meiotic pairing. Moreover, other sex body proteins, including macroH2A1.2 and XMR, do not preferentially localize with the sex chromosomes in the absence of H2AX. Thus, H2AX is required for the chromatin remodeling and associated silencing in male meiosis.
Collapse
Affiliation(s)
- Oscar Fernandez-Capetillo
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Kwan KY, Moens PB, Wang JC. Infertility and aneuploidy in mice lacking a type IA DNA topoisomerase III beta. Proc Natl Acad Sci U S A 2003; 100:2526-31. [PMID: 12591952 PMCID: PMC151374 DOI: 10.1073/pnas.0437998100] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report that disruption of the mouse TOP3 beta gene encoding DNA topoisomerase III beta, one of the two mammalian type IA DNA topoisomerases, leads to a progressive reduction in fecundity. The litter size in crosses of top3 beta(-/-) mice decreases over time and through successive generations, and this decrease seems to reflect embryonic death rather than impaired fertilization. These observations are suggestive of a gradual accumulation of chromosomal defects in germ cells lacking DNA topoisomerase III beta, and this interpretation is supported by the observation of a high incidence of aneuploidy in the spermatocytes of infertile top3 beta(-/-) males. Cytogenetic examination of spermatocytes of wild-type mice also indicates that DNA topoisomerase III beta becomes prominently associated with the asynaptic regions of the XY bivalents during pachytene, and that there is a time lag between the appearance of chromosome-bound DNA topoisomerase III beta and Rad51, a protein known to be involved in an early step of homologous recombination. We interpret these findings, together with the known mechanistic characteristics of different subfamilies of DNA topoisomerases, in terms of a specific role of a type IA DNA topoisomerase in the resolution of meiotic double-Holliday junctions without crossing over. This interpretation is most likely applicable to mitotic cells as well and can explain the universal presence of at least one type IA DNA topoisomerase in all organisms.
Collapse
Affiliation(s)
- Kelvin Y Kwan
- Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138, USA
| | | | | |
Collapse
|
42
|
Lanzone C, Bidau CJ, Giménez MD, Santos JL. Synaptic behaviour and morphological modifications of the X and Y chromosomes during pachytene in three species of Ctenomys (Rodentia, Caviomorpha, Ctenomyidae). Genome 2002; 45:1110-5. [PMID: 12502256 DOI: 10.1139/g02-075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Synaptic behaviour and the progression of morphological differentiation of the XY chromosome pair during pachytene was studied for the first time in three species of the South American subterranean rodents of the genus Ctenomys (tuco-tucos). In general, synapsis progression in the sex pair could be subdivided into four substages: (i) initial partial synapsis of the X and Y chromosome axes and beginning of the differentiation of the unsynapsed regions; (ii) complete or almost complete synapsis of the Y axis accompanied with morphological differentiation of the unsynapsed region of the X chromosome; (iii) a novel stage exclusive to Ctenomys perrensi consisting in a retraction of the free X axis, associated with the formation of a homogeneous and dense structure along the synaptic region, which leads to the achievement of full synapsis between sex chromosomes; or (iv) an increase in morphological complexity involving extreme splitting of the XY pair. The implications of the peculiar synaptic behaviour displayed by sex chromosomes in C. perrensi, a species complex highly polymorphic for Robertsonian translocations, are discussed in relation to both the triggering of the pachytene checkpoint and the avoidance of non-homologous associations between sex chromosomes and the asynaptic pericentromeric regions of trivalents in translocation heterozygotes.
Collapse
Affiliation(s)
- C Lanzone
- Laboratorio de Genética Evolutiva, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Félix de Azara 1552, (3300) Posadas, Misiones, Argentina
| | | | | | | |
Collapse
|
43
|
Turner JMA, Mahadevaiah SK, Elliott DJ, Garchon HJ, Pehrson JR, Jaenisch R, Burgoyne PS. Meiotic sex chromosome inactivation in male mice with targeted disruptions of Xist. J Cell Sci 2002; 115:4097-105. [PMID: 12356914 DOI: 10.1242/jcs.00111] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
X chromosome inactivation occurs twice during the life cycle of placental mammals. In normal females, one X chromosome in each cell is inactivated early in embryogenesis, while in the male, the X chromosome is inactivated together with the Y chromosome in spermatogenic cells shortly before or during early meiotic prophase. Inactivation of one X chromosome in somatic cells of females serves to equalise X-linked gene dosage between males and females, but the role of male meiotic sex chromosome inactivation (MSCI) is unknown. The inactive X-chromosome of somatic cells and male meiotic cells share similar properties such as late replication and enrichment for histone macroH2A1.2, suggesting a common mechanism of inactivation. This possibility is supported by the fact that Xist RNA that mediates somatic X-inactivation is expressed in the testis of male mice and humans. In the present study we show that both Xist RNA and Tsix RNA, an antisense RNA that controls Xist function in the soma, are expressed in the testis in a germ-cell-dependent manner. However, our finding that MSCI and sex-body formation are unaltered in mice with targeted mutations of Xist that prevent somatic X inactivation suggests that somatic X-inactivation and MSCI occur by fundamentally different mechanisms.
Collapse
Affiliation(s)
- James M A Turner
- Division of Developmental Genetics, National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | | | | | | | | | | | | |
Collapse
|
44
|
Moens PB, Kolas NK, Tarsounas M, Marcon E, Cohen PE, Spyropoulos B. The time course and chromosomal localization of recombination-related proteins at meiosis in the mouse are compatible with models that can resolve the early DNA-DNA interactions without reciprocal recombination. J Cell Sci 2002; 115:1611-22. [PMID: 11950880 DOI: 10.1242/jcs.115.8.1611] [Citation(s) in RCA: 253] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During mouse meiosis, the early prophase RAD51/DMC1 recombination protein sites, which are associated with the chromosome cores and which serve as markers for ongoing DNA-DNA interactions, are in ten-fold excess of the eventual reciprocal recombinant events. Most, if not all, of these early interactions are eliminated as prophase progresses. The manner in which these sites are eliminated is the focus of this investigation. We report that these sites acquire replication protein A, RPA and the Escherichia coliMUTS homologue, MSH4p, and somewhat later the Bloom helicase, BLM, while simultaneously losing the RAD51/DMC1 component. Eventually the RPA component is also lost and BLM sites remain. At that time, the MUTL homologue, MLH1p,which is essential for reciprocal recombination in the mouse, appears in numbers and locations that correspond to the distribution of reciprocal recombination events. However, the MLH1 foci do not appear to coincide with the remaining BLM sites. The MLH1p is specifically localized to electron-microscope-defined recombination nodules. We consider the possibility that the homology-search RAD51/DMC1 complexes are involved in homologous chromosome synapsis but that most of these early DNA-DNA interactions are later resolved by the anti-recombination RPA/MSH4/BLM-topoisomerase complex,thereby preventing the formation of superfluous reciprocal recombinant events.
Collapse
Affiliation(s)
- Peter B Moens
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada.
| | | | | | | | | | | |
Collapse
|
45
|
Kelly WG, Schaner CE, Dernburg AF, Lee MH, Kim SK, Villeneuve AM, Reinke V. X-chromosome silencing in the germline of C. elegans. Development 2002; 129:479-92. [PMID: 11807039 PMCID: PMC4066729 DOI: 10.1242/dev.129.2.479] [Citation(s) in RCA: 224] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Germline maintenance in the nematode C. elegans requires global repressive mechanisms that involve chromatin organization. During meiosis, the X chromosome in both sexes exhibits a striking reduction of histone modifications that correlate with transcriptional activation when compared with the genome as a whole. The histone modification spectrum on the X chromosome corresponds with a lack of transcriptional competence, as measured by reporter transgene arrays. The X chromosome in XO males is structurally analogous to the sex body in mammals, contains a histone modification associated with heterochromatin in other species and is inactivated throughout meiosis. The synapsed X chromosomes in hermaphrodites also appear to be silenced in early meiosis, but genes on the X chromosome are detectably expressed at later stages of oocyte meiosis. Silencing of the sex chromosome during early meiosis is a conserved feature throughout the nematode phylum, and is not limited to hermaphroditic species.
Collapse
Affiliation(s)
| | | | - Abby F. Dernburg
- Lawrence Berkeley National Laboratory, One Cyclotron Road MS-84-171 and Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Min-Ho Lee
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stuart K. Kim
- Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Anne M. Villeneuve
- Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Valerie Reinke
- Department of Genetics, Yale University School of Medicine, New Haven, CN 06520, USA
| |
Collapse
|
46
|
Turner JM, Burgoyne PS, Singh PB. M31 and macroH2A1.2 colocalise at the pseudoautosomal region during mouse meiosis. J Cell Sci 2001; 114:3367-75. [PMID: 11591824 DOI: 10.1242/jcs.114.18.3367] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Progression through meiotic prophase is associated with dramatic changes in chromosome condensation. Two proteins that have been implicated in effecting these changes are the mammalian HP1-like protein M31 (HP1β or MOD1) and the unusual core histone macroH2A1.2. Previous analyses of M31 and macroH2A1.2 localisation in mouse testis sections have indicated that both proteins are components of meiotic centromeric heterochromatin and of the sex body, the transcriptionally inactive domain of the X and Y chromosomes. This second observation has raised the possibility that these proteins co-operate in meiotic sex chromosome inactivation. In order to investigate the roles of M31 and macroH2A1.2 in meiosis in greater detail, we have examined their localisation patterns in surface-spread meiocytes from male and female mice. Using this approach, we report that, in addition to their previous described staining patterns, both proteins localise to a focus within the portion of the pseudoautosomal region (PAR) that contains the steroid sulphatase (Sts) gene. In light of the timing of its appearance and of its behaviour in sex-chromosomally variant mice, we suggest a role for this heterochromatin focus in preventing complete desynapsis of the terminally associated X and Y chromosomes prior to anaphase I.
Collapse
Affiliation(s)
- J M Turner
- Laboratory of Developmental Genetics, National Institute for Medical Research, Mill Hill London, NW7 1AA, UK
| | | | | |
Collapse
|