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Podgrajsek R, Hodzic A, Stimpfel M, Kunej T, Peterlin B. Insight into the complexity of male infertility: a multi-omics review. Syst Biol Reprod Med 2024; 70:73-90. [PMID: 38517373 DOI: 10.1080/19396368.2024.2317804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 02/06/2024] [Indexed: 03/23/2024]
Abstract
Male infertility is a reproductive disorder, accounting for 40-50% of infertility. Currently, in about 70% of infertile men, the cause remains unknown. With the introduction of novel omics and advancement in high-throughput technology, potential biomarkers are emerging. The main purpose of our work was to overview different aspects of omics approaches in association with idiopathic male infertility and highlight potential genes, transcripts, non-coding RNA, proteins, and metabolites worth further exploring. Using the Gene Ontology (GO) analysis, we aimed to compare enriched GO terms from each omics approach and determine their overlapping. A PubMed database screening for the literature published between February 2014 and June 2022 was performed using the keywords: male infertility in association with different omics approaches: genomics, epigenomics, transcriptomics, ncRNAomics, proteomics, and metabolomics. A GO enrichment analysis was performed using the Enrichr tool. We retrieved 281 global studies: 171 genomics (DNA level), 21 epigenomics (19 of methylation and two histone residue modifications), 15 transcriptomics, 31 non-coding RNA, 29 proteomics, two protein posttranslational modification, and 19 metabolomics studies. Gene ontology comparison showed that different omics approaches lead to the identification of different molecular factors and that the corresponding GO terms, obtained from different omics approaches, do not overlap to a larger extent. With the integration of novel omics levels into the research of idiopathic causes of male infertility, using multi-omic systems biology approaches, we will be closer to finding the potential biomarkers and consequently becoming aware of the entire spectrum of male infertility, their cause, prognosis, and potential treatment.
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Affiliation(s)
- Rebeka Podgrajsek
- Department of Human Reproduction, University Medical Center Ljubljana, Ljubljana, Slovenia
| | - Alenka Hodzic
- Clinical Institute of Genomic Medicine, University Medical Center Ljubljana, Ljubljana, Slovenia
- Faculty of Health Sciences, University of Novo mesto, Novo Mesto, Slovenia
| | - Martin Stimpfel
- Department of Human Reproduction, University Medical Center Ljubljana, Ljubljana, Slovenia
- Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Tanja Kunej
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Domžale, Slovenia
| | - Borut Peterlin
- Clinical Institute of Genomic Medicine, University Medical Center Ljubljana, Ljubljana, Slovenia
- Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
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Olszewska M, Wiland E, Wanowska E, Huleyuk N, Chernykh VB, Zastavna D, Kurpisz M. Analysis of sperm chromosomes in six carriers
of rare and common Robertsonian translocations. POSTEP HIG MED DOSW 2021. [DOI: 10.5604/01.3001.0014.8122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Introduction: Robertsonian translocation (RobT) is the central fusion of the long arms of two acrocentric
chromosomes, leading to 45 chromosomes in humans. The most common ones are rob(13;14)
and rob(14;21) (91%). Other types of RobT are so-called rare cases. In the general population
RobTs occur with a frequency of approximately 0.123%, but among men with reproductive
failure this value rises 9-fold. Infertility in RobT carriers is associated with the formation of
unbalanced spermatozoa resulting from segregation of the chromosomes involved in trivalent
during the meiotic prophase. In spermatozoa of many RobT carriers an increased level
of chromosomal aneuploidy is observed.
Materials and Methods: We examined the hyperhaploidy level of chromosomes 7, 9, 18, 21, 22, X and Y in spermatozoa
of 6 RobT unrelated carriers: two carriers with rare rob(13;15), one with rare rob(13;22), and
three of the common rob(13;14). Results were compared with the control data from a group
of 7 fertile men with a normal karyotype. Fluorescent in situ hybridization (FISH) was applied.
Results: We found an increased level of sperm aneuploidy regarding at least one of the analyzed
chromosomes in each of the carriers, while in rare RobTs interchromosomal effect (ICE) was
observed. Meiotic segregation pattern of a rare rob(13;15) carrier revealed the 76% of normal
/balanced spermatozoa.
Disucussion: Due to the relatively high population frequency of RobTs, their influence on reproductive
failure, hight risk of imbalancement in prenatal diagnosis (7%), and small amount of data for
rare RobTs, each newly characterized case is valuable in genetic counseling.
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Affiliation(s)
- Marta Olszewska
- Institute of Human Genetics, Polish Academy of Sciences, Poland
| | - Ewa Wiland
- Institute of Human Genetics, Polish Academy of Sciences, Poland
| | | | - Nataliya Huleyuk
- Institute of Hereditary Pathology, Ukrainian Academy of Medical Sciences, Ukraine
| | - Vyacheslav B. Chernykh
- Research Centre for Medical Genetics, Russian Academy of Medical Sciences, Russian Federation
| | - Danuta Zastavna
- Institute of Hereditary Pathology, Ukrainian Academy of Medical Sciences, Ukraine
| | - Maciej Kurpisz
- Institute of Human Genetics, Polish Academy of Sciences, Poland
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Wiland E, Olszewska M, Woźniak T, Kurpisz M. How much, if anything, do we know about sperm chromosomes of Robertsonian translocation carriers? Cell Mol Life Sci 2020; 77:4765-4785. [PMID: 32514588 PMCID: PMC7658086 DOI: 10.1007/s00018-020-03560-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 05/08/2020] [Accepted: 05/22/2020] [Indexed: 12/11/2022]
Abstract
In men with oligozoospermia, Robertsonian translocations (RobTs) are the most common type of autosomal aberrations. The most commonly occurring types are rob(13;14) and rob(14;21), and other types of RobTs are described as 'rare' cases. Based on molecular research, all RobTs can be broadly classified into Class 1 and Class 2. Class 1 translocations produce the same breakpoints within their RobT type, but Class 2 translocations are predicted to form during meiosis or mitosis through a variety of mechanisms, resulting in variation in the breakpoint locations. This review seeks to analyse the available data addressing the question of whether the molecular classification of RobTs into Classes 1 and 2 and/or the type of DD/GG/DG symmetry of the involved chromosomes is reflected in the efficiency of spermatogenesis. The lowest frequency value calculated for the rate of alternate segregants was found for rob(13;15) carriers (Class 2, symmetry DD) and the highest for rob(13;21) carriers (Class 2, DG symmetry). The aneuploidy values for the rare RobT (Class 2) and common rob(14;21) (Class 1) groups together exhibited similarities while differing from those for the common rob(13;14) (Class 1) group. Considering the division of RobT carriers into those with normozoospermia and those with oligoasthenozoospermia, it was found that the number of carriers with elevated levels of aneuploidy was unexpectedly quite similar and high (approx. 70%) in the two subgroups. The reason(s) that the same RobT does not always show a similar destructive effect on fertility was also pointed out.
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Affiliation(s)
- Ewa Wiland
- Institute of Human Genetics, Polish Academy of Sciences, ul. Strzeszynska 32, 60-479, Poznan, Poland
| | - Marta Olszewska
- Institute of Human Genetics, Polish Academy of Sciences, ul. Strzeszynska 32, 60-479, Poznan, Poland
| | - Tomasz Woźniak
- Institute of Human Genetics, Polish Academy of Sciences, ul. Strzeszynska 32, 60-479, Poznan, Poland
| | - Maciej Kurpisz
- Institute of Human Genetics, Polish Academy of Sciences, ul. Strzeszynska 32, 60-479, Poznan, Poland.
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Zhang H, Wang R, Yu Y, Zhu H, Li L, Yang X, Hu X, Liu R. Non-Robertsonian translocations involving chromosomes 13, 14, or 15 in male infertility: 28 cases and a review of the literature. Medicine (Baltimore) 2019; 98:e14730. [PMID: 30817623 PMCID: PMC6831198 DOI: 10.1097/md.0000000000014730] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
For genetic counseling of male carriers of chromosomal translocations, the specific chromosomes and breakpoints involved in the translocation are relevant to know. The structural chromosomal abnormalities may lead to abnormal sperm counts, infertility, and miscarriage. These are related to the specific chromosomes and breakpoints involved in the translocation. To date, over 200 cases of non-Robertsonian translocation in male carriers have been described that involve chromosomes 13, 14, or 15.This study reports of 28 male carriers from our clinic with balanced reciprocal translocations of chromosome 13, 14, or 15, and a literature review of 201 cases. The 28 male carriers from our clinic were diagnosed by cytogenetic analyses: 19 subjects suffered from pregestational infertility and 9 from gestational infertility. The most common translocations were t(7;13), t(10;14), and t(3;15), observed respectively in 13 (46%), 8 (29%), and 8 (29%) of our subjects. The literature cases (n = 201) involved chromosome 13 (n = 83, 41%), chromosome 14 (n = 56, 28%) or 15 (n = 62, 31%) in which 75 breakpoints were identified, the most common breakpoint, 13q22, was observed in 12 subjects (6%), followed by 14q32 (n = 11), 15q15 (n = 9), and 15q22 (n = 9). Most breakpoints were related to gestational infertility, while breakpoints at 13p13, 13p12, 13p11.2, 13p11, 13q11, 13q15, 14p12, 14p10, 15p13, 15p10, and 15q22.2 were associated with pregestational infertility.Carriers of non-Robertsonian translocations involving chromosome 13, 14, or 15 and experiencing infertility should receive counseling with regard to chromosomal breakpoints as there seem to be consequences for treatment. Intracytoplasmic sperm injection with preimplantation genetic diagnosis (PGD) for the carriers with oligozoospermia, microscopic testicular sperm extraction or sperm from the sperm bank for the carriers with azoospermia should be considered for pregestational infertility. The carriers with gestational infertility can choose PGD or prenatal diagnosis.
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Affiliation(s)
- Hongguo Zhang
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Ruixue Wang
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Yang Yu
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Haibo Zhu
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Leilei Li
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Xiao Yang
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Xiaonan Hu
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Ruizhi Liu
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
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Amir H, Barbash-Hazan S, Kalma Y, Frumkin T, Malcov M, Samara N, Hasson J, Reches A, Azem F, Ben-Yosef D. Time-lapse imaging reveals delayed development of embryos carrying unbalanced chromosomal translocations. J Assist Reprod Genet 2018; 36:315-324. [PMID: 30421343 DOI: 10.1007/s10815-018-1361-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 10/30/2018] [Indexed: 11/28/2022] Open
Abstract
PURPOSE The purpose of the study was to compare the morphokinetic parameters of embryos carrying balanced chromosomal translocations with those carrying unbalanced chromosomal translocations using time-lapse microscopy. METHODS The study group included 270 embryos that underwent biopsies on day 3 for preimplantation genetic diagnosis (PGD) for chromosomal translocations in our unit between 2013 and 2015. All embryos were incubated under time-lapse microscopy and evaluated for timing of developmental events up to day 5. The timing of these events was compared between balanced and unbalanced embryos, potentially viable and nonviable variants, and maternal versus paternal inheritance of the translocation. RESULTS The PGD analysis found that 209 (77%) of the 270 biopsied embryos carried an unbalanced translocation. Embryos carrying unbalanced translocations, which are expected to lead to implantation failure or miscarriage, cleaved less synchronously and were delayed in time of cleavage to the 4-cell stage (t4) and in time of start of blastulation (tSB) compared with balanced embryos (P < 0.05). Furthermore, embryos carrying nonviable translocations demonstrated a significant delay at the time of pronuclei fading (tPNf) compared with those carrying potentially viable translocations (P < 0.05). Embryos whose unbalanced translocations were of maternal origin were significantly delayed in most of the morphokinetic parameters (including tPNf, t2, t3, t4, t6, t7, t8, cc2, s2, and tSB) compared with embryos carrying balanced translocations (P < 0.05). CONCLUSIONS Embryos carrying unbalanced chromosomal translocations mainly of maternal origin undergo delayed development and asynchronous cleavage that may lead to implantation failure or miscarriage.
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Affiliation(s)
- Hadar Amir
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Shiri Barbash-Hazan
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Yael Kalma
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Tsvia Frumkin
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Mira Malcov
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Nivin Samara
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Joseph Hasson
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Adi Reches
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Foad Azem
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel
| | - Dalit Ben-Yosef
- IVF Lab & Wolfe PGD-Stem Cell Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, 6 Weizman Street, 6423906, Tel Aviv, Israel. .,Department of Cell Biology and Development, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.
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Lamotte A, Martinez G, Devillard F, Hograindleur JP, Satre V, Coutton C, Harbuz R, Amblard F, Lespinasse J, Benchaib M, Bessonnat J, Brouillet S, Hennebicq S. Is sperm FISH analysis still useful for Robertsonian translocations? Meiotic analysis for 23 patients and review of the literature. Basic Clin Androl 2018; 28:5. [PMID: 29760927 PMCID: PMC5937048 DOI: 10.1186/s12610-018-0069-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/08/2018] [Indexed: 01/09/2023] Open
Abstract
Background Robertsonian translocations (RobT) are common structural chromosome rearrangements where carriers display a majority of chromosomally balanced spermatozoa from alternate segregation mode. According to some monotony observed in the rates of balanced segregation, is sperm FISH analysis obsolete for RobT carriers? Methods Retrospective cohort research study on 23 patients analyzed in our center from 2003 to 2017 and compared to the data of 187 patients in literature from 1983 to 2017. Robertsonian translocation carriers were divided in six groups according to the chromosomes involved in the translocation: 9 patients from our center and 107 from literature carrying 45,XY,der(13;14) karyotype, 3 and 35 patients respectively with 45,XY,der(14;21), 5 and 11 patients respectively with 45,XY,der(13;15), 4 and 7 patients respectively with 45,XY,der(14;15), 1 and 4 patients respectively with 45,XY,der(13;22),and 1 and 10 patients respectively with 45,XY,der(14;22). Results Alternate segregation mode is predominant in our group of Robertsonian translocation carriers with 73.45% ±8.05 of balanced spermatozoa (min 50.92%; max 89.99%). These results are compliant with the data from literature for all translocations types (p > 0.05) and are consistent among the different types of Robertsonian translocations (p > 0.05) except for der(13;15) that exhibit lower balanced spermatozoa rates (p < 0.05 versus der(13;14), der(14;21), (13;21) and der(15;22)). Normozoospermic patients also display a significantly (p < 0.01) higher rate of balanced sperm cells than patients with abnormal seminograms whatever the defect implied. Conclusions According to the discrepancies observed between der(13;15) and all the other Rob T carriers, the differences observed among patients presenting normal and abnormal sperm parameters and the input in genetical counselling, sperm FISH does not seem obsolete for these patients. Moreover, it seems important to collect more data for rare RobT.
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Affiliation(s)
- Anna Lamotte
- CHU de Grenoble, UF de Biologie de la procréation, F-38000 Grenoble, France.,3Université Grenoble Alpes, F-38000 Grenoble, France
| | - Guillaume Martinez
- CHU de Grenoble, UF de Génétique Chromosomique, F-38000 Grenoble, France.,3Université Grenoble Alpes, F-38000 Grenoble, France.,Team 'Genetics Epigenetics and Therapies of Infertility', Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
| | | | - Jean-Pascal Hograindleur
- 3Université Grenoble Alpes, F-38000 Grenoble, France.,Team 'Genetics Epigenetics and Therapies of Infertility', Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
| | - Véronique Satre
- CHU de Grenoble, UF de Génétique Chromosomique, F-38000 Grenoble, France.,3Université Grenoble Alpes, F-38000 Grenoble, France.,Team 'Genetics Epigenetics and Therapies of Infertility', Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
| | - Charles Coutton
- CHU de Grenoble, UF de Génétique Chromosomique, F-38000 Grenoble, France.,3Université Grenoble Alpes, F-38000 Grenoble, France.,Team 'Genetics Epigenetics and Therapies of Infertility', Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
| | - Radu Harbuz
- CHU de Grenoble, UF de Génétique Chromosomique, F-38000 Grenoble, France
| | - Florence Amblard
- CHU de Grenoble, UF de Génétique Chromosomique, F-38000 Grenoble, France
| | | | | | - Julien Bessonnat
- CHU de Grenoble, UF de Biologie de la procréation, F-38000 Grenoble, France
| | - Sophie Brouillet
- CHU de Grenoble, UF de Biologie de la procréation, F-38000 Grenoble, France.,3Université Grenoble Alpes, F-38000 Grenoble, France
| | - Sylviane Hennebicq
- CHU de Grenoble, UF de Biologie de la procréation, F-38000 Grenoble, France.,3Université Grenoble Alpes, F-38000 Grenoble, France.,Team 'Genetics Epigenetics and Therapies of Infertility', Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
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Meiotic behaviour of evolutionary sex-autosome translocations in Bovidae. Chromosome Res 2016; 24:325-38. [PMID: 27136937 DOI: 10.1007/s10577-016-9524-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 04/12/2016] [Accepted: 04/17/2016] [Indexed: 10/21/2022]
Abstract
The recurrent occurrence of sex-autosome translocations during mammalian evolution suggests common mechanisms enabling a precise control of meiotic synapsis, recombination and inactivation of sex chromosomes. We used immunofluorescence and FISH to study the meiotic behaviour of sex chromosomes in six species of Bovidae with evolutionary sex-autosome translocations (Tragelaphus strepsiceros, Taurotragus oryx, Tragelaphus imberbis, Tragelaphus spekii, Gazella leptoceros and Nanger dama ruficollis). The autosomal regions of fused sex chromosomes showed normal synapsis with their homologous counterparts. Synapsis in the pseudoautosomal region (PAR) leads to the formation of characteristic bivalent (in T. imberbis and T. spekii with X;BTA13/Y;BTA13), trivalent (in T. strepsiceros and T. oryx with X/Y;BTA13 and G. leptoceros with X;BTA5/Y) and quadrivalent (in N. dama ruficollis with X;BTA5/Y;BTA16) structures at pachynema. However, when compared with other mammals, the number of pachynema lacking MLH1 foci in the PAR was relatively high, especially in T. imberbis and T. spekii, species with both sex chromosomes involved in sex autosome translocations. Meiotic transcriptional inactivation of the sex-autosome translocations assessed by γH2AX staining was restricted to their gonosomal regions. Despite intraspecies differences, the evolutionary fixation of sex-autosome translocations among bovids appears to involve general mechanisms ensuring sex chromosome pairing, synapsis, recombination and inactivation.
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