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Tilliole P, Fix S, Godin JD. hnRNPs: roles in neurodevelopment and implication for brain disorders. Front Mol Neurosci 2024; 17:1411639. [PMID: 39086926 PMCID: PMC11288931 DOI: 10.3389/fnmol.2024.1411639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/17/2024] [Indexed: 08/02/2024] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) constitute a family of multifunctional RNA-binding proteins able to process nuclear pre-mRNAs into mature mRNAs and regulate gene expression in multiple ways. They comprise at least 20 different members in mammals, named from A (HNRNP A1) to U (HNRNP U). Many of these proteins are components of the spliceosome complex and can modulate alternative splicing in a tissue-specific manner. Notably, while genes encoding hnRNPs exhibit ubiquitous expression, increasing evidence associate these proteins to various neurodevelopmental and neurodegenerative disorders, such as intellectual disability, epilepsy, microcephaly, amyotrophic lateral sclerosis, or dementias, highlighting their crucial role in the central nervous system. This review explores the evolution of the hnRNPs family, highlighting the emergence of numerous new members within this family, and sheds light on their implications for brain development.
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Affiliation(s)
- Pierre Tilliole
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, IGBMC, Illkirch, France
- Centre National de la Recherche Scientifique, CNRS, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, INSERM, U1258, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Simon Fix
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, IGBMC, Illkirch, France
- Centre National de la Recherche Scientifique, CNRS, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, INSERM, U1258, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Juliette D. Godin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, IGBMC, Illkirch, France
- Centre National de la Recherche Scientifique, CNRS, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, INSERM, U1258, Illkirch, France
- Université de Strasbourg, Strasbourg, France
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Silva TDL, Gondro C, Fonseca PADS, da Silva DA, Vargas G, Neves HHDR, Filho IC, Teixeira CDS, Albuquerque LGD, Carvalheiro R. Testicular hypoplasia in Nellore Cattle: Genetic analysis and functional analysis of genome-wide association study results. J Anim Breed Genet 2023; 140:185-197. [PMID: 36321505 DOI: 10.1111/jbg.12747] [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: 08/05/2022] [Accepted: 10/12/2022] [Indexed: 02/11/2023]
Abstract
Characterized by the incomplete development of the germinal epithelium of the seminiferous tubules, Testicular hypoplasia (TH) leads to decreased sperm concentration, increased morphological changes in sperm and azoospermia. Economic losses resulting from the disposal of affected bulls reduce the efficiency of meat production systems. A genome-wide association study and functional analysis were performed to identify genomic windows and the underlying positional candidate genes associated with TH in Nellore cattle. Phenotypic and pedigree data from 207,195 animals and genotypes (461,057 single nucleotide polymorphism, SNP) from 17,326 sires were used in this study. TH was evaluated as a binary trait measured at 18 months of age. A possible correlated response on TH resulting from the selection for scrotal circumference was evaluated by using a two-trait analysis. Thus, estimated breeding values were calculated by fitting a linear-threshold animal model in a Bayesian approach. The SNP effects were estimated using the weighted single-step genomic BLUP method. Twelve non-overlapping windows of 20 adjacent SNP that explained more than 1% of the additive genetic variance were selected for candidate gene annotation. Functional and gene prioritization analysis of the candidate genes identified genes (KHDRBS3, GPX5, STAR, ERLIN2), which might play an important role in the expression of TH due to their known roles in the spermatogenesis process, synthesis of steroids and lipid metabolism.
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Affiliation(s)
- Thales de Lima Silva
- Department of Animal Science, Sao Paulo State University, School of Agriculture and Veterinarian Sciences, Jaboticabal, Brazil
| | - Cedric Gondro
- Department of Animal Science, College of Agriculture and Natural Resources, Michigan State University, East Lansing, Michigan, USA
| | | | | | - Giovana Vargas
- Department of Animal Science, Sao Paulo State University, School of Agriculture and Veterinarian Sciences, Jaboticabal, Brazil
| | | | - Ivan Carvalho Filho
- Department of Animal Science, Sao Paulo State University, School of Agriculture and Veterinarian Sciences, Jaboticabal, Brazil
| | - Caio de Souza Teixeira
- Department of Animal Science, Sao Paulo State University, School of Agriculture and Veterinarian Sciences, Jaboticabal, Brazil
| | - Lucia Galvão de Albuquerque
- Department of Animal Science, Sao Paulo State University, School of Agriculture and Veterinarian Sciences, Jaboticabal, Brazil.,National Council for Scientific and Technological Development (CNPq), Brasília, Brazil
| | - Roberto Carvalheiro
- Department of Animal Science, Sao Paulo State University, School of Agriculture and Veterinarian Sciences, Jaboticabal, Brazil.,National Council for Scientific and Technological Development (CNPq), Brasília, Brazil
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Zheng Y, Li X, Jiao Y, Wu C. High-Risk Human Papillomavirus Oncogenic E6/E7 mRNAs Splicing Regulation. Front Cell Infect Microbiol 2022; 12:929666. [PMID: 35832386 PMCID: PMC9271614 DOI: 10.3389/fcimb.2022.929666] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/19/2022] [Indexed: 11/22/2022] Open
Abstract
High-risk human papillomavirus infection may develop into a persistent infection that is highly related to the progression of various cancers, including cervical cancer and head and neck squamous cell carcinomas. The most common high-risk subtypes are HPV16 and HPV18. The oncogenic viral proteins expressed by high-risk HPVs E6/E7 are tightly involved in cell proliferation, differentiation, and cancerous transformation since E6/E7 mRNAs are derived from the same pre-mRNA. Hence, the alternative splicing in the E6/E7-coding region affects the balance of the E6/E7 expression level. Interrupting the balance of E6 and E7 levels results in cell apoptosis. Therefore, it is crucial to understand the regulation of E6/E7 splice site selection and the interaction of splicing enhancers and silencers with cellular splicing factors. In this review, we concluded the relationship of different E6/E7 transcripts with cancer progression, the known splicing sites, and the identified cis-regulatory elements within high-risk HPV E6/E7-coding region. Finally, we also reviewed the role of various splicing factors in the regulation of high-risk HPV oncogenic E6/E7 mRNA splicing.
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Affiliation(s)
- Yunji Zheng
- School of Pharmacy, Binzhou Medical University, Yantai, China
| | - Xue Li
- School of Pharmacy, Binzhou Medical University, Yantai, China
| | - Yisheng Jiao
- School of Biomedical Engineering, Dalian University of Technology, Dalian, China
| | - Chengjun Wu
- School of Biomedical Engineering, Dalian University of Technology, Dalian, China
- *Correspondence: Chengjun Wu,
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Deletion of RBMX RGG/RG motif in Shashi-XLID syndrome leads to aberrant p53 activation and neuronal differentiation defects. Cell Rep 2021; 36:109337. [PMID: 34260915 DOI: 10.1016/j.celrep.2021.109337] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/29/2021] [Accepted: 06/11/2021] [Indexed: 01/01/2023] Open
Abstract
RNA-binding proteins play important roles in X-linked intellectual disability (XLID). In this study, we investigate the contribution of the XLID-associated RBMX in neuronal differentiation. We show that RBMX-depleted cells exhibit aberrant activation of the p53 pathway. Moreover, we identify that the RBMX RGG/RG motif is methylated by protein arginine methyltransferase 5 (PRMT5), and this regulates assembly with the SRSF1 splicing factor into higher-order complexes. Depletion of RBMX or disruption of the RBMX/SRSF1 complex in PRMT5-depleted cells reduces SRSF1 binding to the MDM4 precursor (pre-)mRNA, leading to exon 6 exclusion and lower MDM4 protein levels. Transcriptomic analysis of isogenic Shashi-XLID human-induced pluripotent stem cells (hiPSCs) generated using CRISPR-Cas9 reveals a dysregulation of MDM4 splicing and aberrant p53 upregulation. Shashi-XLID neural progenitor cells (NPCs) display differentiation and morphological abnormalities accompanied with excessive apoptosis. Our findings identify RBMX as a regulator of SRSF1 and the p53 pathway, suggesting that the loss of function of the RBMX RGG/RG motif is the cause of Shashi-XLID syndrome.
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Yan Y, Yang X, Liu Y, Shen Y, Tu W, Dong Q, Yang D, Ma Y, Yang Y. Copy number variation of functional RBMY1 is associated with sperm motility: an azoospermia factor-linked candidate for asthenozoospermia. Hum Reprod 2018; 32:1521-1531. [PMID: 28498920 DOI: 10.1093/humrep/dex100] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 04/28/2017] [Indexed: 02/05/2023] Open
Abstract
STUDY QUESTION What is the influence of copy number variation (CNV) in functional RNA binding motif protein Y-linked family 1 (RBMY1) on spermatogenic phenotypes? SUMMARY ANSWER The RBMY1 functional copy dosage is positively correlated with sperm motility, and dosage insufficiency is an independent risk factor for asthenozoospermia. WHAT IS KNOWN ALREADY RBMY1, a multi-copy gene expressed exclusively in the adult testis, is one of the most important candidates for male infertility in the azoospermia factor (AZF) region of the Y-chromosome. RBMY1 encodes an RNA-binding protein that serves as a pre-mRNA splicing regulator during spermatogenesis, and male mice deficient in Rbmy are sterile. STUDY DESIGN, SIZE, DURATION A total of 3127 adult males were recruited from 2009 to 2016; of this group, the dosage of RBMY1 functional copy were investigated in 486 fertile males. In the remaining 2641 males with known spermatogenesis status, 1070 Y-chromosome haplogroup (Y-hg) O3* or O3e carriers without chromosomal aberration or known AZF structure mutations responsible for spermatogenic impairment, including 506 men with normozoospermia and 564 men with oligozoospermia or/and asthenozoospermia, were screened, and the RBMY1 functional copy dosage and copy conversion were determined to explore their associations with sperm phenotypes. The correlation between RBMY1 dosage and its mRNA level or RBMY1 protein level and the correlation between sperm RBMY1 level and motility were analysed in 15 testis tissue samples and eight semen samples. Ten additional semen samples were used to confirm the subcellular localization of RBMY1 in individual sperm. PARTICIPANTS/MATERIALS, SETTING, METHODS All the Han volunteers donating whole blood, semen and testis tissue were from southwest China. RBMY1 copy number, copy conversion, mRNA/protein amount and protein location in sperm were detected using the AccuCopy® assay method, paralog ratio test, quantitative PCR, western blotting and immunofluorescence staining methods, respectively. MAIN RESULTS AND THE ROLE OF CHANCE This study identified Y-hg-independent CNV of functional RBMY1 in the enrolled population. A difference in the distribution of RBMY1 copy number was observed between the group with normal sperm motility and the group with asthenozoospermia. A positive correlation between the RBMY1 copy dosage and sperm motility was identified, and the males with fewer than six copies of RBMY1 showed an elevated risk for asthenozoospermia relative to those with six RBMY1 copies, the most common dosage in the population. The RBMY1 copy dosage was positively correlated with its mRNA and protein level in the testis. Sperm with high motility were found to carry more RBMY1 protein than those with relatively low motility. The RBMY1 protein was confirmed to predominantly localize in the neck and mid-piece region of sperm as well as the principal piece of the sperm tail. Our population study completes a chain of evidence suggesting that RBMY1 influences the susceptibility of males to asthenozoospermia by modulating sperm motility. LIMITATIONS REASONS FOR CAUTION High sequence similarity between the RBMY1 functional copies and a large number of pseudogenes potentially reduces the accuracy of the copy number detection. The mechanism underlying the CNV in RBMY1 is still unclear, and the effect of the structural variations in the RBMY1 copy cluster on the copy dosage of other protein-coding genes located in the region cannot be excluded, which may potentially bias our observations. WIDER IMPLICATIONS OF THE FINDINGS Asthenozoospermia is a multi-factor complex disease with a limited number of proven susceptibility genes. This study identified a novel genomic candidate independently contributing to the condition, enriching our understanding of the role of AZF-linked genes in male reproduction. Our finding provides insight into the physiological and pathological characteristics of RBMY1 in terms of sperm motility, supplies persuasive evidence of the significance of RBMY1 copy number analysis in the clinical counselling of male infertility resulting from asthenozoospermia. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by the National Natural Science Foundation of China (Nos. 81370748 and 30971598). The authors have no conflicts of interest.
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Affiliation(s)
- Yuanlong Yan
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, No. 1, Keyuan Road 4, Gaopeng Street, Chengdu, Sichuan 610041, China
| | - Xiling Yang
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, No. 1, Keyuan Road 4, Gaopeng Street, Chengdu, Sichuan 610041, China
| | - Yunqiang Liu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, No. 1, Keyuan Road 4, Gaopeng Street, Chengdu, Sichuan 610041, China
| | - Ying Shen
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, No. 1, Keyuan Road 4, Gaopeng Street, Chengdu, Sichuan 610041, China
| | - Wenling Tu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, No. 1, Keyuan Road 4, Gaopeng Street, Chengdu, Sichuan 610041, China
| | - Qiang Dong
- Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Dong Yang
- Reproductive Medicine Institute, Chengdu Women's and Children's Central Hospital, Chengdu, Sichuan 610031, China
| | - Yongyi Ma
- Jinjiang Maternal and Child Health Hospital, Chengdu, Sichuan 610016, China
| | - Yuan Yang
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, No. 1, Keyuan Road 4, Gaopeng Street, Chengdu, Sichuan 610041, China
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Colaco S, Modi D. Genetics of the human Y chromosome and its association with male infertility. Reprod Biol Endocrinol 2018; 16:14. [PMID: 29454353 PMCID: PMC5816366 DOI: 10.1186/s12958-018-0330-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 02/06/2018] [Indexed: 12/12/2022] Open
Abstract
The human Y chromosome harbors genes that are responsible for testis development and also for initiation and maintenance of spermatogenesis in adulthood. The long arm of the Y chromosome (Yq) contains many ampliconic and palindromic sequences making it predisposed to self-recombination during spermatogenesis and hence susceptible to intra-chromosomal deletions. Such deletions lead to copy number variation in genes of the Y chromosome resulting in male infertility. Three common Yq deletions that recur in infertile males are termed as AZF (Azoospermia Factor) microdeletions viz. AZFa, AZFb and AZFc. As estimated from data of nearly 40,000 Y chromosomes, the global prevalence of Yq microdeletions is 7.5% in infertile males; however the European infertile men are less susceptible to Yq microdeletions, the highest prevalence is in Americans and East Asian infertile men. In addition, partial deletions of the AZFc locus have been associated with infertility but the effect seems to be ethnicity dependent. Analysis of > 17,000 Y chromosomes from fertile and infertile men has revealed an association of gr/gr deletion with male infertility in Caucasians and Mongolian men, while the b2/b3 deletion is associated with male infertility in African and Dravidian men. Clinically, the screening for Yq microdeletions would aid the clinician in determining the cause of male infertility and decide a rational management strategy for the patient. As these deletions are transmitted to 100% of male offspring born through assisted reproduction, testing of Yq deletions will allow the couples to make an informed choice regarding the perpetuation of male infertility in future generations. With the emerging data on association of Yq deletions with testicular cancers and neuropsychiatric conditions long term follow-up data is urgently needed for infertile men harboring Yq deletions. If found so, the information will change the current the perspective of androgenetics from infertility and might have broad implication in men health.
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Affiliation(s)
- Stacy Colaco
- Department of Molecular and Cellular Biology, ICMR-National Institute for Research in Reproductive Health, JM Street, Parel, Mumbai, Maharashtra, 400012, India
| | - Deepak Modi
- Department of Molecular and Cellular Biology, ICMR-National Institute for Research in Reproductive Health, JM Street, Parel, Mumbai, Maharashtra, 400012, India.
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DMRTC2, PAX7, BRACHYURY/T and TERT Are Implicated in Male Germ Cell Development Following Curative Hormone Treatment for Cryptorchidism-Induced Infertility. Genes (Basel) 2017; 8:genes8100267. [PMID: 29019938 PMCID: PMC5664117 DOI: 10.3390/genes8100267] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/25/2017] [Accepted: 10/05/2017] [Indexed: 12/14/2022] Open
Abstract
Defective mini-puberty results in insufficient testosterone secretion that impairs the differentiation of gonocytes into dark-type (Ad) spermatogonia. The differentiation of gonocytes into Ad spermatogonia can be induced by administration of the gonadotropin-releasing hormone agonist, GnRHa (Buserelin, INN)). Nothing is known about the mechanism that underlies successful GnRHa treatment in the germ cells. Using RNA-sequencing of testicular biopsies, we recently examined RNA profiles of testes with and without GnRHa treatment. Here, we focused on the expression patterns of known gene markers for gonocytes and spermatogonia, and found that DMRTC2, PAX7, BRACHYURY/T, and TERT were associated with defective mini-puberty and were responsive to GnRHa. These results indicate novel testosterone-dependent genes and provide valuable insight into the transcriptional response to both defective mini-puberty and curative GnRHa treatment, which prevents infertility in man with one or both undescended (cryptorchid) testes.
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Meyfour A, Pooyan P, Pahlavan S, Rezaei-Tavirani M, Gourabi H, Baharvand H, Salekdeh GH. Chromosome-Centric Human Proteome Project Allies with Developmental Biology: A Case Study of the Role of Y Chromosome Genes in Organ Development. J Proteome Res 2017; 16:4259-4272. [PMID: 28914051 DOI: 10.1021/acs.jproteome.7b00446] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
One of the main goals of Chromosome-Centric Human Proteome Project is to identify protein evidence for missing proteins (MPs). Here, we present a case study of the role of Y chromosome genes in organ development and how to overcome the challenges facing MPs identification by employing human pluripotent stem cell differentiation into cells of different organs yielding unprecedented biological insight into adult silenced proteins. Y chromosome is a male-specific sex chromosome which escapes meiotic recombination. From an evolutionary perspective, Y chromosome has preserved 3% of ancestral genes compared to 98% preservation of the X chromosome based on Ohno's law. Male specific region of Y chromosome (MSY) contains genes that contribute to central dogma and govern the expression of various targets throughout the genome. One of the most well-known functions of MSY genes is to decide the male-specific characteristics including sex, testis formation, and spermatogenesis, which are majorly formed by ampliconic gene families. Beyond its role in sex-specific gonad development, MSY genes in coexpression with their X counterparts, as single copy and broadly expressed genes, inhibit haplolethality and play a key role in embryogenesis. The role of X-Y related gene mutations in the development of hereditary syndromes suggests an essential contribution of sex chromosome genes to development. MSY genes, solely and independent of their X counterparts and/or in association with sex hormones, have a considerable impact on organ development. In this Review, we present major recent findings on the contribution of MSY genes to gonad formation, spermatogenesis, and the brain, heart, and kidney development and discuss how Y chromosome proteome project may exploit developmental biology to find missing proteins.
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Affiliation(s)
- Anna Meyfour
- Department of Molecular Systems Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research , 81589-68433 Tehran, Iran.,Proteomics Research Center, Department of Basic Science, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Sciences , 19839-63113 Tehran, Iran
| | - Paria Pooyan
- Department of Molecular Systems Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research , 81589-68433 Tehran, Iran
| | - Sara Pahlavan
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research , 81589-68433 Tehran, Iran
| | - Mostafa Rezaei-Tavirani
- Proteomics Research Center, Department of Basic Science, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Sciences , 19839-63113 Tehran, Iran
| | - Hamid Gourabi
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute , 19395-4644 Tehran, Iran
| | - Hossein Baharvand
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research , 81589-68433 Tehran, Iran.,Department of Developmental Biology, University of Science and Culture , 19395-4644 Tehran, Iran
| | - Ghasem Hosseini Salekdeh
- Department of Molecular Systems Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research , 81589-68433 Tehran, Iran.,Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran , 31535-1897 Karaj, Iran
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Spermatogenic failure and the Y chromosome. Hum Genet 2017; 136:637-655. [PMID: 28456834 DOI: 10.1007/s00439-017-1793-8] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 03/30/2017] [Indexed: 12/29/2022]
Abstract
The Y chromosome harbors a number of genes essential for testis development and function. Its highly repetitive structure predisposes this chromosome to deletion/duplication events and is responsible for Y-linked copy-number variations (CNVs) with clinical relevance. The AZF deletions remove genes with predicted spermatogenic function en block and are the most frequent known molecular causes of impaired spermatogenesis (5-10% of azoospermic and 2-5% of severe oligozoospermic men). Testing for this deletion has both diagnostic and prognostic value for testicular sperm retrieval in azoospermic men. The most dynamic region on the Yq is the AZFc region, presenting numerous NAHR hotspots leading to partial losses or gains of the AZFc genes. The gr/gr deletion (a partial AZFc deletion) negatively affects spermatogenic efficiency and it is a validated, population-dependent risk factor for oligozoospermia. In certain populations, the Y background may play a role in the phenotypic expression of partial AZFc rearrangements and similarly it may affect the predisposition to specific deletions/duplication events. Also, the Yp contains a gene array, TSPY1, with potential effect on germ cell proliferation. Despite intensive investigations during the last 20 years on the role of this sex chromosome in spermatogenesis, a number of clinical and basic questions remain to be answered. This review is aimed at providing an overview of the role of Y chromosome-linked genes, CNVs, and Y background in spermatogenesis.
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Nistal M, Paniagua R, González-Peramato P, Reyes-Múgica M. Perspectives in Pediatric Pathology, Chapter 16. Klinefelter Syndrome and Other Anomalies in X and Y Chromosomes. Clinical and Pathological Entities. Pediatr Dev Pathol 2016; 19:259-77. [PMID: 25105890 DOI: 10.2350/14-06-1512-pb.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Manuel Nistal
- 1 Department of Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo No. 2, Madrid 28029, Spain
| | - Ricardo Paniagua
- 2 Department of Cell Biology, Universidad de Alcala, Madrid, Spain
| | - Pilar González-Peramato
- 1 Department of Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo No. 2, Madrid 28029, Spain
| | - Miguel Reyes-Múgica
- 3 Department of Pathology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, One Children's Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
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RNA Binding Protein Ptbp2 Is Essential for Male Germ Cell Development. Mol Cell Biol 2015; 35:4030-42. [PMID: 26391954 DOI: 10.1128/mcb.00676-15] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/14/2015] [Indexed: 11/20/2022] Open
Abstract
RNA binding proteins (RBPs) are increasingly recognized as essential factors in tissue development and homeostasis. The polypyrimidine tract binding (PTB) protein family of RBPs are important posttranscriptional regulators of gene expression. In the nervous system, the function and importance of PTB protein 2 (Ptbp2) as a key alternative splicing regulator is well established. Ptbp2 is also abundantly expressed during spermatogenesis, but its role in this developmental program has not been explored. Additionally, the importance of alternative splicing regulation in spermatogenesis is unclear. Here, we demonstrate that Ptbp2 is essential for spermatogenesis. We also describe an improved dual fluorescence flow cytometry strategy to discriminate, quantify, and collect germ cells in different stages of development. Using this approach, in combination with traditional histological methods, we show that Ptbp2 ablation results in germ cell loss due to increased apoptosis of meiotic spermatocytes and postmeiotic arrest of spermatid differentiation. Furthermore, we show that Ptbp2 is required for alternative splicing regulation in the testis, as in brain. Strikingly, not all of the alternatively spliced RNAs examined were sensitive to Ptbp2 loss in both tissues. Collectively, the data provide evidence for an important role for alternative splicing regulation in germ cell development and a central role for Ptbp2 in this process.
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Jamsai D, Lo JCY, McLachlan RI, O'Bryan MK. Genetic variants in the RABL2A gene in fertile and oligoasthenospermic infertile men. Fertil Steril 2014; 102:223-9. [PMID: 24825419 DOI: 10.1016/j.fertnstert.2014.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 03/19/2014] [Accepted: 04/08/2014] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To define RABL2A localization in human sperm and to assess any potential association between RABL2A variants and male infertility associated with oligoasthenospermia. DESIGN Genetic association study. SETTING Public university. PATIENT(S) Australian men: 110 oligoasthenospermic infertile and 105 proven fertile. INTERVENTION(S) Human semen samples processed by immunostaining with high-throughput-sequencing platform to screen the entire protein-coding and flanking exon/intron regions of the RABL2A gene. MAIN OUTCOME MEASURE(S) Presence of RABL2A in human sperm and frequencies of RABL2A genetic variants in fertile and infertile men. RESULT(S) RABL2A localization in sperm was highly conserved between mouse and human, being localized to the tail. Direct DNA sequencing revealed 23 RABL2A genetic variants, including 16 intronic, 6 untranslated region (UTR), and one exonic missense variants. Of these, eight variants have not been previously reported. Although the majority of these variants showed no significant association with fertility status, allelic frequency of the intronic variant 114391996 delC was significantly increased in oligoasthenospermic men. Bioinformatics analysis suggested that the 114391996 delC allele would alter the splicing of RABL2A pre-mRNA. CONCLUSION(S) Our data suggest the 114391996 delC allele in the RABL2A gene may act as a risk factor for oligoasthenospermic infertility in Australian men.
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Affiliation(s)
- Duangporn Jamsai
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
| | - Jennifer Chi Yi Lo
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Robert I McLachlan
- Monash Institute of Medical Research and Prince Henry's Institute of Medical Research, and Department of Obstetrics and Gynecology, Monash Medical Centre, Clayton, Victoria, Australia; Monash IVF, Richmond, Victoria, Australia
| | - Moira K O'Bryan
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
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13
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Schmid R, Grellscheid SN, Ehrmann I, Dalgliesh C, Danilenko M, Paronetto MP, Pedrotti S, Grellscheid D, Dixon RJ, Sette C, Eperon IC, Elliott DJ. The splicing landscape is globally reprogrammed during male meiosis. Nucleic Acids Res 2013; 41:10170-84. [PMID: 24038356 PMCID: PMC3905889 DOI: 10.1093/nar/gkt811] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Meiosis requires conserved transcriptional changes, but it is not known whether there is a corresponding set of RNA splicing switches. Here, we used RNAseq of mouse testis to identify changes associated with the progression from mitotic spermatogonia to meiotic spermatocytes. We identified ∼150 splicing switches, most of which affect conserved protein-coding exons. The expression of many key splicing regulators changed in the course of meiosis, including downregulation of polypyrimidine tract binding protein (PTBP1) and heterogeneous nuclear RNP A1, and upregulation of nPTB, Tra2β, muscleblind, CELF proteins, Sam68 and T-STAR. The sequences near the regulated exons were significantly enriched in target sites for PTB, Tra2β and STAR proteins. Reporter minigene experiments investigating representative exons in transfected cells showed that PTB binding sites were critical for splicing of a cassette exon in the Ralgps2 mRNA and a shift in alternative 5′ splice site usage in the Bptf mRNA. We speculate that nPTB might functionally replace PTBP1 during meiosis for some target exons, with changes in the expression of other splicing factors helping to establish meiotic splicing patterns. Our data suggest that there are substantial changes in the determinants and patterns of alternative splicing in the mitotic-to-meiotic transition of the germ cell cycle.
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Affiliation(s)
- Ralf Schmid
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK, School of Biological and Biomedical Sciences, Durham University, Durham, DH1 3LE, UK, Department of Health Sciences, University of 00135 Rome 'Foro Italico', Rome, Italy, Laboratories of Neuroembryology and of Cellular and Molecular Neurobiology, Fondazione Santa Lucia IRCCS, 00143 Rome, Italy, Department of Public Health and Cell Biology, University of Rome Tor Vergata, 00133 Rome, Italy, Institute of Particle Physics Phenomenology, Durham University, Durham, DH1 3LE, UK and Life Technologies Ltd., Paisley PA4 9RF, UK
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14
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Abid S, Sagare-Patil V, Gokral J, Modi D. Cellular ontogeny of RBMY during human spermatogenesis and its role in sperm motility. J Biosci 2013; 38:85-92. [PMID: 23385816 DOI: 10.1007/s12038-012-9281-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The Y-chromosome-encoded gene RBMY (RNA-binding motif on Y) is a male germline RNA-binding protein and is postulated to be a RNA-splicing regulator. In order to understand the roles of RBMY in different stages of male gamete maturation, the present study aimed at determining its cellular expression during spermatogenesis, spermeogenesis and in mature spermatozoa. In the spermatogonia (cKIT-positive cells), RBMY immunolocalized as two distinct foci, one in the nucleolus and the other in the subnuclear region; in the spermatocytes (cKIT-negative cells), the nucleus had punctuate staining with a subnuclear foci; in the pachytene cells, the protein was localized as a punctuate pattern in the nucleus spread along the elongating chromosomes. In the round and the elongating spermatids, the protein expression was polarized and restricted to the cytoplasm and in the developing mid-piece. In testicular and ejaculated sperm, RBMY was localized to the mid-piece region and weakly in the tail. Incubation of spermatozoa with the RBMY antibody reduced its motility. The spatial differences in expression of RBMY in the germ cells and the presences of this protein in post-meiotic cells and in transcriptionally inert spermatozoa suggest its involvement in multiple functions beyond RNA splicing. One such possible function of RBMY could be its involvement in sperm motility.
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Affiliation(s)
- Shadaan Abid
- Molecular and Cellular Biology Laboratory, National Institute for Research in Reproductive Health, JM Street, Parel, Mumbai 400 012, India
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15
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Genetic dissection of the AZF regions of the human Y chromosome: thriller or filler for male (in)fertility? J Biomed Biotechnol 2010; 2010:936569. [PMID: 20671934 PMCID: PMC2910558 DOI: 10.1155/2010/936569] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 04/23/2010] [Indexed: 12/02/2022] Open
Abstract
The azoospermia factor (AZF) regions consist of three genetic domains in the long arm of the human Y chromosome referred to as AZFa, AZFb and AZFc. These are of importance for male fertility since they are home to genes required for spermatogenesis. In this paper a comprehensive analysis of AZF structure and gene content will be undertaken. Particular care will be given to the molecular mechanisms underlying the spermatogenic impairment phenotypes associated to AZF deletions. Analysis of the 14 different AZF genes or gene families argues for the existence of functional asymmetries between the determinants; while some are prominent players in spermatogenesis, others seem to modulate more subtly the program. In this regard, evidence supporting the notion that DDX3Y, KDM5D, RBMY1A1, DAZ, and CDY represent key AZF spermatogenic determinants will be discussed.
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16
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Dreumont N, Bourgeois CF, Lejeune F, Liu Y, Ehrmann IE, Elliott DJ, Stévenin J. Human RBMY regulates germline-specific splicing events by modulating the function of the serine/arginine-rich proteins 9G8 and Tra2-{beta}. J Cell Sci 2010; 123:40-50. [PMID: 20016065 DOI: 10.1242/jcs.055889] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
RBMY is a male germline RNA binding protein and potential alternative splicing regulator, but the lack of a convenient biological system has made its cellular functions elusive. We found that human RBMY fused to green fluorescent protein was strictly nuclear in transfected cells, but spatially enriched in areas around nuclear speckles with some components of the exon junction complex (EJC). Human RBMY (hRBMY) and the EJC components Magoh and Y14 also physically interacted but, unlike these two proteins, hRBMY protein did not shuttle to the cytoplasm. In addition, it relocalised into nucleolar caps after inhibition of RNA polymerase II transcription. Protein interactions were also detected between RBMY and splicing factors 9G8 and transformer-2 protein homolog beta (Tra2-beta), mediated by multiple regions of the RBMY protein that contain serine/arginine-rich dipeptides, but not by the single region lacking such dipeptides. These interactions modulated the splicing of several pre-mRNAs regulated by 9G8 and Tra2-beta. Importantly, ectopic expression of hRBMY stimulated the inclusion of a testis-enriched exon from the Acinus gene, whereas 9G8 and Tra2-beta repressed this exon. We propose that hRBMY associates with regions of the nucleus enriched in nascent RNA and participates in the regulation of specific splicing events in the germline by modulating the activity of constitutively expressed splicing factors.
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17
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Hermo L, Pelletier RM, Cyr DG, Smith CE. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 5: intercellular junctions and contacts between germs cells and Sertoli cells and their regulatory interactions, testicular cholesterol, and genes/proteins associated with more than one germ cell generation. Microsc Res Tech 2010; 73:409-94. [PMID: 19941291 DOI: 10.1002/jemt.20786] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In the testis, cell adhesion and junctional molecules permit specific interactions and intracellular communication between germ and Sertoli cells and apposed Sertoli cells. Among the many adhesion family of proteins, NCAM, nectin and nectin-like, catenins, and cadherens will be discussed, along with gap junctions between germ and Sertoli cells and the many members of the connexin family. The blood-testis barrier separates the haploid spermatids from blood borne elements. In the barrier, the intercellular junctions consist of many proteins such as occludin, tricellulin, and claudins. Changes in the expression of cell adhesion molecules are also an essential part of the mechanism that allows germ cells to move from the basal compartment of the seminiferous tubule to the adluminal compartment thus crossing the blood-testis barrier and well-defined proteins have been shown to assist in this process. Several structural components show interactions between germ cells to Sertoli cells such as the ectoplasmic specialization which are more closely related to Sertoli cells and tubulobulbar complexes that are processes of elongating spermatids embedded into Sertoli cells. Germ cells also modify several Sertoli functions and this also appears to be the case for residual bodies. Cholesterol plays a significant role during spermatogenesis and is essential for germ cell development. Lastly, we list genes/proteins that are expressed not only in any one specific generation of germ cells but across more than one generation.
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Affiliation(s)
- Louis Hermo
- Faculty of Medicine, Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 2B2.
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18
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Ehrmann I, Dalgliesh C, Tsaousi A, Paronetto MP, Heinrich B, Kist R, Cairns P, Li W, Mueller C, Jackson M, Peters H, Nayernia K, Saunders P, Mitchell M, Stamm S, Sette C, Elliott DJ. Haploinsufficiency of the germ cell-specific nuclear RNA binding protein hnRNP G-T prevents functional spermatogenesis in the mouse. Hum Mol Genet 2008; 17:2803-18. [PMID: 18562473 DOI: 10.1093/hmg/ddn179] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Human HNRNPGT, encoding the protein hnRNP G-T, is one of several autosomal retrogenes derived from RBMX. It has been suggested that HNRNPGT functionally replaces the sex-linked RBMX and RBMY genes during male meiosis. We show here that during normal mouse germ cell development, hnRNP G-T protein is strongly expressed during and after meiosis when proteins expressed from Rbmx or Rbmx-like genes are absent. Amongst these Rbmx-like genes, DNA sequence analyses indicate that two other mouse autosomal Rbmx-derived retrogenes have evolved recently in rodents and one already shows signs of degenerating into a non-expressed pseudogene. In contrast, orthologues of Hnrnpgt are present in all four major groups of placental mammals. The sequence of Hnrnpgt is under considerable positive selection suggesting it performs an important germ cell function in eutherians. To test this, we inactivated Hnrnpgt in ES cells and studied its function during spermatogenesis in chimaeric mice. Although germ cells heterozygous for this targeted allele could produce sperm, they did not contribute to the next generation. Chimaeric mice with a high level of mutant germ cells were infertile with low sperm counts and a high frequency of degenerate seminiferous tubules and abnormal sperm. Chimaeras made from a 1:1 mix of targeted and wild-type ES cell clones transmitted wild-type germ cells only. Our data show that haploinsufficiency of Hnrnpgt results in abnormal sperm production in the mouse. Genetic defects resulting in reduced levels of HNRNPGT could, therefore, be a cause of male infertility in humans.
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Affiliation(s)
- Ingrid Ehrmann
- Institute of Human Genetics, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
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19
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Zeng M, Sun H, Chen S, Wang X, Yang Y, Liu Y, Tao D, Yang Z, Zhang S, Ma Y. Identification of target messenger RNA substrates for mouse RBMY. Mol Hum Reprod 2008; 14:331-6. [PMID: 18492746 DOI: 10.1093/molehr/gan024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Rbmy gene encodes a RNA-binding protein and its expression is limited to the nuclei of germ cells. Previous studies indicate that RBMY may function in pre-mRNA processing during spermatogenesis, although its precise target mRNAs remain unclear. By using specific nucleic acids associated with proteins and immunoprecipitation techniques, we have identified 12 potential target mRNAs bound by mouse RBMY protein from testis. We detect that both mRbmy-1 and mRbmy-2 transcripts co-exist in mouse testis and they differ mainly in the 5'UTR. Importantly, our result shows that mRBMY protein can bind to one of its own transcripts, mRbmy-2, suggesting that mRBMY may affect alternative splicing or regulate the expression of its own gene. Using electrophoretic mobility shift assay, we demonstrated that mRBMY protein can bind to the testis and sperm-specific spa17 mRNA and that the binding domain contains rich oligo(A), suggesting that mRBMY protein may have high affinity to oligo(A) rich sequences. In conclusion, the identification of RBMY target mRNAs will be helpful to further explore the biological function of RBMY in spermatogenesis.
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Affiliation(s)
- Mei Zeng
- Department of Medical Genetics, West China Hospital, Sichuan University, Renmin Nanlu, Section 3 #17, Chengdu 610041, PR China
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20
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Sierra-Montes JM, Pereira-Simon S, Smail SS, Herrera RJ. The silk moth Bombyx mori U1 and U2 snRNA variants are differentially expressed. Gene 2005; 352:127-36. [PMID: 15894437 DOI: 10.1016/j.gene.2005.02.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2004] [Revised: 12/16/2004] [Accepted: 02/22/2005] [Indexed: 10/25/2022]
Abstract
Five U1 and eight U2 isoforms of the silk moth Bombyx mori exhibiting internal nucleotide differences have been previously identified and characterized in various tissues and developmental stages. In this investigation, it is demonstrated that the levels of some snRNA variants differ in egg and silk gland tissue and change during development. Qualitative and quantitative differences in the U1 and U2 variant populations were observed at three developmental points (early, middle and late) of the silk gland (SG) during the fifth instar larval stage of the silk moth. Statistical analyses of the various isoform populations across the fifth instar larval and egg stages show significant differences for some of the U1 and U2 variants. The representation of variant sequences in expressed U1 and U2 sequences (RT-PCR libraries) and in a whole-genome shotgun (WGS) assembly database was confirmed. In addition, conserved elements in the promoter 5'-flanking region of the U1 and U2 variants were identified in the WGS.
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Affiliation(s)
- Julie M Sierra-Montes
- Department of Biological Sciences, OE304, Florida International University, Miami, FL 33199, United States
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21
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Kurihara Y, Watanabe H, Kawaguchi A, Hori T, Mishiro K, Ono M, Sawada H, Uesugi S. Dynamic changes in intranuclear and subcellular localizations of mouse Prrp/DAZAP1 during spermatogenesis: the necessity of the C-terminal proline-rich region for nuclear import and localization. ACTA ACUST UNITED AC 2005; 67:325-33. [PMID: 15700540 DOI: 10.1679/aohc.67.325] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mouse Prrp (mPrrp)/DAZAP1 is a mouse ortholog of Xenopus Prrp, which is involved in vegetal pole localization of Vg1 mRNA in oocytes and is highly expressed in the testis. The mouse protein has been reported to be a shuttling protein which localizes in the nucleus of pre-meiotic spermatogenic cells and round spermatids, and shifts its location into the cytoplasm in elongating spermatids, suggesting that mPrrp may be involved in mRNA transport as well as that of the Xenopus ortholog. We reexamined immunohistochemical analyses of mPrrp/DAZAP1 during spermatogenesis utilizing a newly established monoclonal antibody and reconfirmed it to be a shuttling protein. We also carried out new observations that included remarkable intranuclear movement during spermatogenesis. In addition, we found that a long amino acid stretch which spanned over the C-terminal half of the protein was required for the nuclear import. These observations demonstrated dynamic changes in subnuclear and subcellular localization which might reflect specific functions during spermatogenesis.
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Affiliation(s)
- Yasuyuki Kurihara
- Department of Environment and Natural Sciences, Graduate School of Environment and Information Sciences, Yokohama National University, Hodogaya, Yokohama, Japan.
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22
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Elliott DJ. The role of potential splicing factors including RBMY, RBMX, hnRNPG-T and STAR proteins in spermatogenesis. ACTA ACUST UNITED AC 2005; 27:328-34. [PMID: 15595951 DOI: 10.1111/j.1365-2605.2004.00496.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Investigations into the RBM gene family are uncovering networks of protein interactions which regulate RNA processing, and which might operate downstream of signal transduction pathways. Similar pathways likely operate in germ cells and somatic cells, with RBMY, hnRNPGT and T-STAR proteins providing germ cell-specific components. These pathways may be important for normal germ cell development, and might be compromised in men with Y chromosome deletions affecting RBMY gene expression. The STAR proteins have multiple functions in pre-mRNA splicing, signalling and cell cycle control. These processes might have to be very finely regulated during germ cell development, which involves both two sequential meiotic divisions (meiosis I and II) as well as mitotic (spermatogonial) cell divisions, and which is controlled by paracrine signalling within the testis from Sertoli cells.
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Affiliation(s)
- David J Elliott
- Institute of Human Genetics, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 3BZ, UK.
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23
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Benoff S, Goodwin LO, Millan C, Hurley IR, Pergolizzi RG, Marmar JL. Deletions in L-type calcium channel α1 subunit testicular transcripts correlate with testicular cadmium and apoptosis in infertile men with varicoceles. Fertil Steril 2005; 83:622-34. [PMID: 15749491 DOI: 10.1016/j.fertnstert.2004.07.976] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Revised: 07/30/2004] [Accepted: 07/30/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To identify and understand predictors of successful varicocelectomy. DESIGN Examination of testicular L-type voltage-dependent calcium channel (L-VDCC) mRNAs and proteins in testis biopsies and comparison of presence and absence of various mRNAs with testicular cadmium levels, with apoptosis, and with sperm count change after varicocelectomy. SETTING University clinical urology practice and research laboratories. PATIENT(S) Infertile men with varicocele (left varicocele only, n = 18; bilateral varicoceles, n = 26) and controls (men with obstructive azoospermia undergoing testicular sperm extraction before intracytoplasmic sperm injection; n = 7). INTERVENTION(S) Left testis biopsies by percutaneous needle aspiration biopsy. Varicocele repair by subinguinal approach. MAIN OUTCOME MEASURE(S) Calcium channel mRNA sequence by reverse transcription-polymerase chain reaction and amplicon analysis; calcium channel protein distribution by immunocytochemistry; cadmium levels by atomic absorption and apoptosis by deoxynucleotidyl transferase labeling; and sperm counts in the ejaculate before and after varicocelectomy. RESULT(S) Calcium channel mRNAs are polymorphic in human testis biopsies from different men. Proteins from sequence-deleted exons 7 and/or 8 localize to germ cell membranes. Expression of undeleted L-type calcium channel mRNAs correlates with normal testes cadmium and increased sperm count after varicocelectomy. Apoptosis is lower in such cases. CONCLUSION(S) Expression of normal testicular L-VDCC sequence in exons 7-8 predicts postvaricocelectomy sperm count increase. Deletions may alter calcium channel function and affect testicular cadmium and apoptosis.
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Affiliation(s)
- Susan Benoff
- Fertility Research Laboratories, North Shore-Long Island Jewish Research Institute, North Shore University Hospital, Manhasset, New York, USA
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24
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Tsuei DJ, Hsu HC, Lee PH, Jeng YM, Pu YS, Chen CN, Lee YC, Chou WC, Chang CJ, Ni YH, Chang MH. RBMY, a male germ cell-specific RNA-binding protein, activated in human liver cancers and transforms rodent fibroblasts. Oncogene 2004; 23:5815-22. [PMID: 15184870 DOI: 10.1038/sj.onc.1207773] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The RNA-binding motif (RRM) gene on Y chromosome (RBMY), encoding a male germ cell-specific RNA-binding protein associated with spermatogenesis, was found inserted by hepatitis B virus (HBV) DNA in one childhood hepatocellular carcinoma (HCC). This study is aimed to explore the oncogenic potential of the RBMY protein. The RBMY transcripts, expressed exclusively in the testis of normal people, were detected by reverse transcription-polymerase chain reaction in 36% of HCCs from 90 males and in 67% of hepatoblastoma from six boys. The nontumor liver counter parts, cirrhotic liver tissues from children with biliary atresia, and other types of cancers, such as bile duct, colon, stomach, lung, prostate, and kidney, were all negative for RBMY expression. One to four types of RBMY transcripts, including wild type and variants with N-terminal RRM deletion, C-terminal SRGY (serine-arginine-glycine-tyrosine) boxes deletion, or deletion of both domains, were found in the testis and liver cancer tissues. The wild-type RBMY protein was expressed in the nucleus and demonstrated its tumorigenicity by transformation of mouse fibroblast NIH3T3 cells and in vivo tumor formation. The RBMY variant protein with deletion of C-terminal exons 9-12 was trapped in the cytoplasm and showed decreased tumorigenicity. Our results suggest that RBMY is a new candidate oncogene specific for male liver cancer.
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Affiliation(s)
- Daw-Jen Tsuei
- Department of Pediatrics, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taiwan
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25
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Kleiman SE, Yogev L, Gal-Yam EN, Hauser R, Gamzu R, Botchan A, Paz G, Yavetz H, Maymon BBS, Schreiber L, Barzilai S, Amariglio N, Rechavi G, Simon AJ. Reduced human germ cell-less (HGCL) expression in azoospermic men with severe germinal cell impairment. JOURNAL OF ANDROLOGY 2003; 24:670-5. [PMID: 12954656 DOI: 10.1002/j.1939-4640.2003.tb02725.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Germ cell-less (GCL) protein is a nuclear envelope protein highly conserved between the mammalian and Drosophila orthologues. In Drosophila, maternal GCL protein is required to establish the germ lineage during embryonic development. In mammals, it is suggested that the GCL function is mainly in spermatogenesis and that it might be related to the ability of mouse GCL to repress transcription. Using reverse transcriptase-polymerase chain reaction analyses, we investigated the role of human GCL (HGCL) in spermatogenesis by studying its expression in the testicular tissue of 67 azoospermic men with normal karyotype and no Y-chromosome microdeletion. Their testicular biopsy specimens underwent meticulous histological and cytological analysis as well as molecular analysis with various markers of spermatogenesis (RBM1, DAZ, and CDY1). The rate of X-Y and 18 chromosome bivalent formation during meiosis was additionally assessed in 22 of these biopsy specimens and correlated to HGCL expression. Expression of HGCL was affected in parallel with the severity of testicular impairment found. Defective sperm motility was associated with the absence of HGCL. Nevertheless, the absence of HGCL expression did not influence the normal process of chromosome bivalent formation in meiosis. Our results suggest that HGCL is not essential for the chromosomal events of meiosis but might be involved in later aspects of spermatogenesis.
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Affiliation(s)
- Sandra E Kleiman
- Institute for the Study of Fertility, Lis Maternity Hospital, Tel Aviv, Israel.
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26
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Guo TB, Boros LG, Chan KC, Hikim APS, Hudson AP, Swerdloff RS, Mitchell AP, Salameh WA. Spermatogenetic expression of RNA-binding motif protein 7, a protein that interacts with splicing factors. JOURNAL OF ANDROLOGY 2003; 24:204-14. [PMID: 12634307 DOI: 10.1002/j.1939-4640.2003.tb02664.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We have previously shown that a ubiquitously expressed RNA splicing factor, RNA-binding motif 7 (RBM7), cloned from a testis complementary DNA library, enhances messenger RNA (mRNA) splicing in vitro and is expressed in a cell-restricted fashion. Herein, we detail its mRNA and protein expression in the rodent testis. RNA in situ hybridization shows that Rbm7 expression in rat germ cells closely parallels the entry and progression of meiosis. The expression commences in type B spermatogonia, it rises during the preleptotene stage, peaks in leptotene spermatocytes, and declines afterward, but increases again in stage-associated pachytene spermatocytes. An affinity-purified polyclonal antibody raised against a peptide corresponding to amino acids 202-224 of the mouse RBM7 recognized the predicted 35 kd protein both in testicular lysates and in in vitro translation reactions. Consistent with the in situ hybridization results, RBM7 immunoreactivity was also detected in type B spermatogonia, spanned the entire period of spermatocyte development, and extended to round and early elongated spermatids. Moreover, RBM7 appeared nuclear up to the mid pachytene stage and became cytoplasmic thereafter. Consistent with its role in RNA splicing, yeast 2-hybrid and glutathione S-transferase pull-down assays show that RBM7 interacts with splicing factor 3b subunit 2 (SAP145), and with the splicing regulator, SRp20. These interactions and the nuclear localization of RBM7 provide insights into its function in pre-mRNA processing in developing spermatocytes during entry into meiosis and progression through the meiotic prophase.
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Affiliation(s)
- Taylor B Guo
- Department of Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
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27
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Abstract
Normal spermatogenesis is a complex process that depends on many factors. Genetics plays a major role in many of these factors including providing a normal hormonal milieu, the development of the testis and ductal system, and control of the stepwise maturation of sperm in the testis. The Y chromosome plays a key role in testis determination and control of spermatogenesis. Understanding how these genes work together can elucidate of the exact cause of infertility in some patients once thought to have idiopathic infertility. It is not only important that patients understand the cause of their infertility. Using sperm from these men to attain pregnancies by assisted reproductive techniques will probably result in infertile male offspring. Additional consequences are currently unknown but are the topic of research investigations.
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Affiliation(s)
- Rodrigo Pagani
- Division of Male Reproductive Medicine and Surgery, Scott Department of Urology, Baylor College of Medicine, 6560 Fannin Suite 2100, Houston, Texas 77030, USA
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28
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Abstract
Classical cytogenetic mapping has identified a locus on the long arm of the human Y chromosome that is required for spermatogenesis and is termed AZF, an acronym for the hypothetical azoospermia factor encoded by this locus. Recent molecular attempts to identify the gene corresponding to this locus have revealed that there are at least three genes in three separate microdeletion intervals. Two of these microdeletion intervals contain genes encoding proteins with potential roles in RNA metabolism. These genes are members of Y-encoded gene families with autosomal homologues. The cell biology of one of these genes, RBM (an acronym of RNA binding motif), is complex and suggests a role in pre-mRNA splicing.
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Affiliation(s)
- David J. Elliott
- Medical Research Council Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
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Saunders PTK, Maguire SM, Macpherson S, Fenelon MC, Sakakibara S, Okano H. RNA binding protein Musashi1 is expressed in sertoli cells in the rat testis from fetal life to adulthood. Biol Reprod 2002; 66:500-7. [PMID: 11804968 DOI: 10.1095/biolreprod66.2.500] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The Musashi1 (Msi1) gene identified in mouse is a member of a subfamily of RNA binding proteins that are highly conserved across species. Msi1 expression is highly enriched in proliferative cells within the developing central nervous system. Within the testis, proliferation and differentiation of germ cells takes place within the seminiferous epithelium, where these cells are supported physically and functionally by Sertoli cells that do not themselves proliferate following the onset of puberty. RNA binding proteins expressed in testicular germ cells are essential for normal fertility. Preliminary data suggested the mRNA for Msi1 was present in ovary; therefore, we used an Msi1-specific cRNA and monoclonal antibody to investigate whether Msi1 was expressed in the testis. Msi1 mRNA was expressed in rat testis from birth until adulthood; in situ hybridization revealed silver grains within the seminiferous epithelium. Immunohistochemical studies demonstrated that at all ages examined (from Fetal Day 14.5 until adulthood) Msi1 protein was expressed in Sertoli cells. In fetal and adult rat ovaries, Msi1 was detected in granulosa cells and their precursors. In Sertoli cells, protein was detected in both cytoplasmic and nuclear compartments; in adult testes, the immunointensity of the nuclear staining was stage dependent, with highest levels of expression in Sertoli cells at stages I-VI. In rat gonads, the RNA binding protein Msi1 is expressed in both proliferating and nonproliferating Sertoli and granulosa cells.
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Affiliation(s)
- P T K Saunders
- MRC Human Reproductive Sciences Unit, Edinburgh EH3 9ET, United Kingdom.
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30
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Abstract
Differentiation in several stem cell systems is associated with major morphological changes in global nuclear shape. We studied the fate of inner-nuclear structures, splicing factor-rich foci and Cajal (coiled) bodies in differentiating hemopoietic, testis and skin tissues. Using antibodies to the splicing factors PSF, U2AF(65) and snRNPs we find that these proteins localize in foci throughout the nuclei of immature bone marrow cells. Yet, when granulocytic cells differentiate and their nuclei condense and become segmented, the staining localizes in a unique compact and thread-like structure. The splicing factor-rich foci concentrate in the interior of these nuclei while the nuclear periphery and areas of highly compact chromatin remain devoid of these molecules. Differentiated myeloid cells do not stain for p80 coilin, the marker for Cajal bodies. Immature myeloid cells contain Cajal bodies although these usually do not coloclaize with PSF-rich foci. Following complete inhibition of transcription in myeloid cells, the threaded PSF pattern becomes localized in several foci in the different lobes of mature granulocytes while in human HL-60 immature myeloid leukemia cells PSF is found in the perinucleolar compartment. Studies of other differentiating stem cell systems show that PSF staining disappears completely in differentiated, transcriptionally inactive sperm cells, is scarce as cells migrate from the inner skin layers outward and is lost as cells of the hair follicle mature. We conclude that the formation and distribution of splicing factor-rich foci in the nucleus during differentiation of various cell lineages is dependent on the levels of chromatin condensation and the differentiation status of the cell.
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Affiliation(s)
- Y Shav-Tal
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
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31
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Abstract
Three different spermatogenesis loci have been mapped on the Y chromosome and named "azoospermia factors" (AZFa, b, and c). Deletions in these regions remove one or more of the candidate genes (DAZ, RBMY, USP9Y, and DBY) and cause severe testiculopathy leading to male infertility. We have reviewed the literature and the most recent advances in Y chromosome mapping, focusing our attention on the correlation between Y chromosome microdeletions and alterations of spermatogenesis. More than 4,800 infertile patients were screened for Y microdeletions and published. Such deletions determine azoospermia more frequently than severe oligozoospermia and involve especially the AZFc region including the DAZ gene family. Overall, the prevalence of Y chromosome microdeletions is 4% in oligozoospermic patients, 14% in idiopathic severely oligozoospermic men, 11% in azoospermic men, and 18% in idiopathic azoospermic subjects. Patient selection criteria appear to substantially influence the prevalence of microdeletions. No clear correlation exists between the size and localization of the deletions and the testicular phenotype. However, it is clear that larger deletions are associated with the most severe testicular damage. Patients with Y chromosome deletions frequently have sperm either in the ejaculate or within the testis and are therefore suitable candidates for assisted reproduction techniques. This possibility raises a number of medical and ethical concerns, since the use of spermatozoa carrying Y chromosome deletions may produce pregnancies, but in such cases the genetic anomaly will invariably be passed on to male offspring.
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Affiliation(s)
- C Foresta
- University of Padova, Department of Medical and Surgical Sciences, Clinica Medica 3, 35128 Padua, Italy.
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Lifschitz-Mercer B, Elliott DJ, Schreiber-Bramante L, Leider-Trejo L, Eisenthal A, Bar-Shira Maymon B. Intratubular germ cell neoplasia: associated infertility and review of the diagnostic modalities. Int J Surg Pathol 2001; 9:93-8. [PMID: 11484508 DOI: 10.1177/106689690100900202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The incidence of testicular neoplasia has increased, and its early detection has become a pressing clinical issue. The strong association between male subfertility and risk of testicular neoplasia is consistent with the existence of common pathogenetic factors. Most forms of testicular germ tumors are believed to stem from a common precursor, intratubular germ cell neoplasia (ITGCN), also known as testicular carcinoma in situ. Identification of ITGCN cells in testicular biopsies, however, is a diagnostic challenge and markers are sorely needed to assist in the accurate identification of the lesion.
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Affiliation(s)
- B Lifschitz-Mercer
- Institute of Pathology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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Maymon BB, Elliott DJ, Kleiman SE, Yogev L, Hauser R, Botchan A, Schreiber L, Cooke HJ, Paz G, Yavetz H. The contribution of RNA-binding motif (RBM) antibody to the histopathologic evaluation of testicular biopsies from infertile men. Hum Pathol 2001; 32:36-41. [PMID: 11172293 DOI: 10.1053/hupa.2001.20887] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Testicular biopsies of infertile men are often characterized by mixed histologic patterns, with different types of spermatogenic impairments being found in adjacent seminiferous tubules. RNA-binding motif (RBM) is a nuclear protein expressed exclusively in the male germ cell line. We reasoned that RBM might be a useful marker to identify germ cells in testicular sections, particularly in biopsies with mixed histologic phenotype and small focal concentrations of spermatogenesis. Testicular biopsies from azoospermic men were immunohistochemically evaluated for RBM expression. RBM expression was detectable in spermatogonia, spermatocytes, and round spermatids in biopsies of men with obstructive azoospermia and normal spermatogenesis. No specific cell staining was shown in cases of Sertoli-cell-only (SCO) syndrome. In biopsies of patients with spermatogenic disorders, all the germ cells were stained up to and including the stage level of the arrest in spermatogenesis. This approach enabled identification of small focal concentrations of spermatogenesis in a biopsy previously classified as being SCO by hematoxylin and eosin staining. Thus, RBM can be a useful immunohistochemical marker for the specific identification of germ cells and provide greater accuracy in the histopathologic evaluation of testicular biopsies.
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Affiliation(s)
- B B Maymon
- Institute for the Study of Fertility, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Israel
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Kleiman SE, Lagziel A, Yogev L, Botchan A, Paz G, Yavetz H. Expression of CDY1 may identify complete spermatogenesis. Fertil Steril 2001; 75:166-73. [PMID: 11163833 DOI: 10.1016/s0015-0282(00)01639-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the expression of deleted in azoospermia (DAZ), RNA-binding motif (RBM), and chromodomain y1 (CDY1) genes in the testes of men with azoospermia with variable histopathologies. DESIGN Prospective study. SETTING Andrology laboratory of a university-affiliated maternity hospital. PATIENT(S) Sixty-six men with azoospermia. INTERVENTION(S) Testicular sperm extraction. MAIN OUTCOME MEASURE(S) The results of gene expression in testicular tissue tested by RT-PCR were correlated with those of histopathologically and microscopically examined minced testicular tissue. Y chromosome microdeletion testing and karyotyping were performed, as was direct sequencing of CDY1-PCR products. RESULT(S) CDY1-minor expression was detected in all biopsies in which mature spermatids/spermatozoa were observed by histological analysis and/or in the minced tissue. CDY1-minor expression was also detected in two biopsies with arrest at the spermatocyte stage during which no mature spermatids/spermatozoa were observed. A previously unreported CDY1-minor alternative splicing transcript was identified. DAZ and RBM gene expressions were detected in all biopsies in which at least a few germinal cells in early stages were found and in one biopsy histologically determined as Sertoli cell only. CONCLUSION(S) Our preliminary results suggest that CDY1-minor expression might increase the prospect for complete spermatogenesis, while RBM and DAZ expression can only be indicative of the presence of germinal cells.
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Affiliation(s)
- S E Kleiman
- Institute for the Study of Fertility, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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35
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Abstract
It was suggested by Ronald Fisher in 1931 that genes involved in benefit to the male (including spermatogenesis genes) would accumulate on the Y chromosome. The analysis of mouse Y chromosome deletions and the discovery of microdeletions of the human Y chromosome associated with diverse defective spermatogenic phenotypes has revealed the presence of intervals containing one or more genes controlling male germ cell differentiation. These intervals have been mapped, cloned and examined in detail for functional genes. This review discusses the genes mapping to critical spermatogenesis intervals and the evidence indicating which are the most likely candidates underlying Y-linked male infertility.
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Affiliation(s)
- N A Affara
- Department of Pathology, University of Cambridge, UK
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36
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Grootegoed JA, Siep M, Baarends WM. Molecular and cellular mechanisms in spermatogenesis. BAILLIERE'S BEST PRACTICE & RESEARCH. CLINICAL ENDOCRINOLOGY & METABOLISM 2000; 14:331-43. [PMID: 11097779 DOI: 10.1053/beem.2000.0083] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Mammalian spermatogenesis shows a strict control of many specific molecular and cellular events. This control involves Sertoli cell-germ cell interaction, as well as a programmed performance of changes in chromatin structure and gene expression in the developing germ cells. In recent years, much knowledge about the functions of defined genes in spermatogenesis has been gained by making use of mouse transgenic and gene knockout models. Several of these models are discussed in this brief overview, with an emphasis on genes encoding proteins involved in the control of gene transcription, mRNA translation, DNA repair and protein ubiquitination. A better understanding of the molecular and cellular biology of spermatogenesis in the mouse may provide concepts that can improve our understanding of human male infertility and may also lead to the identification of novel targets for contraceptive intervention.
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Affiliation(s)
- J A Grootegoed
- Department of Endocrinology and Reproduction, Erasmus University Rotterdam, 3000 DR Rotterdam, TheNetherlands
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37
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Abstract
This article reviews chromosomal and genetic disorders in the context of male fertility. Particular emphasis is on those disorders, which are encountered, in clinical practice including Klinefelter's syndrome, Kallman's syndrome, Androgen insensitivity, Y microdeletions, Y fertility gene deletions, and cystic fibrosis gene mutations. These disorders are discussed in relation to the aetiology of male fertility and also risks to children who are born of fathers with these disorders. A list of fathers' categories is proposed for outcome studies for children born after IVF-ICSI. Finally a question is proposed to catalyse debate about germ line therapy.
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Affiliation(s)
- T B Hargreave
- Department of Urology, Western General Hospital, Edinburgh, Scotland, UK
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38
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Elliott DJ, Bourgeois CF, Klink A, Stévenin J, Cooke HJ. A mammalian germ cell-specific RNA-binding protein interacts with ubiquitously expressed proteins involved in splice site selection. Proc Natl Acad Sci U S A 2000; 97:5717-22. [PMID: 10823932 PMCID: PMC18499 DOI: 10.1073/pnas.97.11.5717] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
RNA-binding motif (RBM) genes are found on all mammalian Y chromosomes and are implicated in spermatogenesis. Within human germ cells, RBM protein shows a similar nuclear distribution to components of the pre-mRNA splicing machinery. To address the function of RBM, we have used protein-protein interaction assays to test for possible physical interactions between these proteins. We find that RBM protein directly interacts with members of the SR family of splicing factors and, in addition, strongly interacts with itself. We have mapped the protein domains responsible for mediating these interactions and expressed the mouse RBM interaction region as a bacterial fusion protein. This fusion protein can pull-down several functionally active SR protein species from cell extracts. Depletion and add-back experiments indicate that these SR proteins are the only splicing factors bound by RBM which are required for the splicing of a panel of pre-mRNAs. Our results suggest that RBM protein is an evolutionarily conserved mammalian splicing regulator which operates as a germ cell-specific cofactor for more ubiquitously expressed pre-mRNA splicing activators.
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Affiliation(s)
- D J Elliott
- Medical Research Council Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, Scotland.
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39
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40
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Vogel T, Speed RM, Teague P, Cooke HJ. Mice with Y chromosome deletion and reduced Rbm genes on a heterozygous Dazl1 null background mimic a human azoospermic factor phenotype. Hum Reprod 1999; 14:3023-9. [PMID: 10601091 DOI: 10.1093/humrep/14.12.3023] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A subset of azoospermia or oligozoospermia patients have microdeletions in defined regions of their Y chromosome, namely the AZFa, b, and c regions. Candidate genes in humans that may cause the azoospermia factor (AZF) phenotype have been assigned to these regions and can include the DAZ and RBM genes. Part of the variability in the AZFc phenotype might be due to interaction between the effects of deleting the DAZ and RBM genes. We mimicked human deletions of RBM and DAZ in the mouse by crossing male mice with a deleted Y chromosome with a reduced number of Rbm genes (Y(d1)) to heterozygote Dazl1 null female mice to study the interaction of the Dazl1 and Rbm or other genes located in the Y(d1) deletion interval. Dazl-/+ Y(d1) animals showed a significant reduction in the sperm count (P < 0.001), an increase of abnormal sperm heads and prominent mid-piece defects of the tails compared to either mutation alone (P < 0.001). Hence, Dazl1 and the genes removed on the Y(d1) chromosome are active in different pathways contributing to different stages of spermatogenesis. Reduction of Dazl1 and Rbm genes as well as/or deletion of the Y chromosome in mice gives rise to a phenotype similar to the heterogeneous AZFc phenotype observed in humans.
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Affiliation(s)
- T Vogel
- MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
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41
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Venables JP, Eperon I. The roles of RNA-binding proteins in spermatogenesis and male infertility. Curr Opin Genet Dev 1999; 9:346-54. [PMID: 10377282 DOI: 10.1016/s0959-437x(99)80052-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
RNA-binding proteins are essential for spermatogenesis: they are required in the nucleus of germ cells, for the production of specific mRNA isoforms, and in the cytoplasm - where proteins required for chromatin condensation and for changes in cell morphology are translated long after transcription ceases. Some of the RNA targets and the RNA-binding proteins themselves have been identified recently. Both nuclear and cytoplasmic proteins are affected in examples of azoospermia in men.
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Affiliation(s)
- J P Venables
- Department of Biochemistry University of Leicester University Road, Leicester, LE1 7RH, UK.
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42
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Affiliation(s)
- Y F Lau
- Division of Cell and Developmental Genetics, Department of Medicine, VAMC-111C5, University of California, San Francisco, 4150 Clement Street, San Francisco, CA 94121, USA
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43
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McElreavey K, Krausz C. Sex Chromosome Genetics '99. Male infertility and the Y chromosome. Am J Hum Genet 1999; 64:928-33. [PMID: 10090876 PMCID: PMC1377815 DOI: 10.1086/302351] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- K McElreavey
- Immunogénétique Humaine, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, France.
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