1
|
Jiang L, Guo T, Song X, Jiang H, Lu M, Luo J, Rossi V, He Y. MSH7 confers quantitative variation in pollen fertility and boosts grain yield in maize. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:1372-1386. [PMID: 38263872 PMCID: PMC11022798 DOI: 10.1111/pbi.14272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/15/2023] [Accepted: 12/08/2023] [Indexed: 01/25/2024]
Abstract
Fertile pollen is critical for the survival, fitness, and dispersal of flowering plants, and directly contributes to crop productivity. Extensive mutational screening studies have been carried out to dissect the genetic regulatory network determining pollen fertility, but we still lack fundamental knowledge about whether and how pollen fertility is controlled in natural populations. We used a genome-wide association study (GWAS) to show that ZmGEN1A and ZmMSH7, two DNA repair-related genes, confer natural variation in maize pollen fertility. Mutants defective in these genes exhibited abnormalities in meiotic or post-meiotic DNA repair, leading to reduced pollen fertility. More importantly, ZmMSH7 showed evidence of selection during maize domestication, and its disruption resulted in a substantial increase in grain yield for both inbred and hybrid. Overall, our study describes the first systematic examination of natural genetic effects on pollen fertility in plants, providing valuable genetic resources for optimizing male fertility. In addition, we find that ZmMSH7 represents a candidate for improvement of grain yield.
Collapse
Affiliation(s)
- Luguang Jiang
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
| | - Ting Guo
- Institute of Genetics and Developmental Biology, Key Laboratory of Seed InnovationChinese Academy of SciencesBeijingChina
| | - Xinyuan Song
- Jilin Provincial Key Laboratory of Agricultural Biotechnology, Agro‐Biotechnology Research InstituteJilin Academy of Agricultural SciencesChangchunChina
| | - Huan Jiang
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
| | - Minhui Lu
- Center for Crop Functional Genomics and Molecular BreedingChina Agricultural UniversityBeijingChina
| | - Jinhong Luo
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
- Institute of Genetics and Developmental Biology, Key Laboratory of Seed InnovationChinese Academy of SciencesBeijingChina
| | - Vincenzo Rossi
- Council for Agricultural Research and EconomicsResearch Centre for Cereal and Industrial CropsBergamoItaly
| | - Yan He
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
- Institute of Genetics and Developmental Biology, Key Laboratory of Seed InnovationChinese Academy of SciencesBeijingChina
| |
Collapse
|
2
|
Abe H, Yeh YH, Munakata Y, Ishiguro KI, Andreassen PR, Namekawa SH. Active DNA damage response signaling initiates and maintains meiotic sex chromosome inactivation. Nat Commun 2022; 13:7212. [PMID: 36443288 PMCID: PMC9705562 DOI: 10.1038/s41467-022-34295-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 10/13/2022] [Indexed: 11/29/2022] Open
Abstract
Meiotic sex chromosome inactivation (MSCI) is an essential process in the male germline. While genetic experiments have established that the DNA damage response (DDR) pathway directs MSCI, due to limitations to the experimental systems available, mechanisms underlying MSCI remain largely unknown. Here we establish a system to study MSCI ex vivo, based on a short-term culture method, and demonstrate that active DDR signaling is required both to initiate and maintain MSCI via a dynamic and reversible process. DDR-directed MSCI follows two layers of modifications: active DDR-dependent reversible processes and irreversible histone post-translational modifications. Further, the DDR initiates MSCI independent of the downstream repressive histone mark H3K9 trimethylation (H3K9me3), thereby demonstrating that active DDR signaling is the primary mechanism of silencing in MSCI. By unveiling the dynamic nature of MSCI, and its governance by active DDR signals, our study highlights the sex chromosomes as an active signaling hub in meiosis.
Collapse
Affiliation(s)
- Hironori Abe
- grid.27860.3b0000 0004 1936 9684Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616 USA ,grid.274841.c0000 0001 0660 6749Department of Chromosome Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, 860-0811 Japan
| | - Yu-Han Yeh
- grid.27860.3b0000 0004 1936 9684Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616 USA
| | - Yasuhisa Munakata
- grid.27860.3b0000 0004 1936 9684Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616 USA
| | - Kei-Ichiro Ishiguro
- grid.274841.c0000 0001 0660 6749Department of Chromosome Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, 860-0811 Japan
| | - Paul R. Andreassen
- grid.24827.3b0000 0001 2179 9593Division of Experimental Hematology & Cancer Biology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229 USA
| | - Satoshi H. Namekawa
- grid.27860.3b0000 0004 1936 9684Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616 USA
| |
Collapse
|
3
|
Li Y, Meng R, Li S, Gu B, Xu X, Zhang H, Tan X, Shao T, Wang J, Xu D, Wang F. The ZFP541-KCTD19 complex is essential for pachytene progression by activating meiotic genes during mouse spermatogenesis. J Genet Genomics 2022; 49:1029-1041. [PMID: 35341968 DOI: 10.1016/j.jgg.2022.03.005] [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: 12/13/2021] [Revised: 03/11/2022] [Accepted: 03/11/2022] [Indexed: 12/29/2022]
Abstract
Meiosis is essential for fertility in sexually reproducing species and this sophisticated process has been extensively studied. Notwithstanding these efforts, key factors involved in meiosis have not been fully characterized. In this study, we investigate the regulatory roles of zinc finger protein 541 (ZFP541) and its interacting protein potassium channel tetramerization domain containing 19 (KCTD19) in spermatogenesis. ZFP541 is expressed from leptotene to the round spermatid stage, while the expression of KCTD19 is initiated in pachytene. Depletion of Zfp541 or Kctd19 leads to infertility in male mice and delays progression from early to mid/late pachynema. In addition, Zfp541-/- spermatocytes show abnormal programmed DNA double-strand break repair, impaired crossover formation and resolution, and asynapsis of the XY chromosomes. ZFP541 interacts with KCTD19, histone deacetylase 1/2 (HDAC1/2), and deoxynucleotidyl transferase terminal-interacting protein 1 (DNTTIP1). Moreover, ZFP541 binds to and activates the expression of genes involved in meiosis and post-meiosis including Kctd19; in turn, KCTD19 promotes the transcriptional activation activity of ZFP541. Taken together, our studies reveal that the ZFP541/KCTD19 signaling complex, acting as a key transcription regulator, plays an indispensable role in male fertility by regulating pachytene progression.
Collapse
Affiliation(s)
- Yushan Li
- The School of Public Health, Xinxiang Medical University, Xinxiang, Henan 453003, China
| | - Ranran Meng
- College of Life Sciences, Beijing Normal University, Beijing 100875, China; National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Shanze Li
- College of Life Sciences, Beijing Normal University, Beijing 100875, China; National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Bowen Gu
- National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Xiaotong Xu
- National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Haihang Zhang
- National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Xinshui Tan
- National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Tianyu Shao
- National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Jiawen Wang
- National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Dan Xu
- National Institute of Biological Sciences Beijing, Beijing 102206, China
| | - Fengchao Wang
- National Institute of Biological Sciences Beijing, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
4
|
Abstract
The cell cycle is the series of events that take place in a cell that drives it to divide and produce two new daughter cells. Through more than 100 years of efforts by scientists, we now have a much clearer picture of cell cycle progression and its regulation. The typical cell cycle in eukaryotes is composed of the G1, S, G2, and M phases. The M phase is further divided into prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that controls the activity of various Cdk-cyclin complexes. Most cellular events, including DNA duplication, gene transcription, protein translation, and post-translational modification of proteins, occur in a cell-cycle-dependent manner. To understand these cellular events and their underlying molecular mechanisms, it is desirable to have a population of cells that are traversing the cell cycle synchronously. This can be achieved through a process called cell synchronization. Many methods have been developed to synchronize cells to the various phases of the cell cycle. These methods could be classified into two groups: synchronization methods using chemical inhibitors and synchronization methods without using chemical inhibitors. All these methods have their own merits and shortcomings.
Collapse
Affiliation(s)
- Zhixiang Wang
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
5
|
Alavattam KG, Maezawa S, Andreassen PR, Namekawa SH. Meiotic sex chromosome inactivation and the XY body: a phase separation hypothesis. Cell Mol Life Sci 2021; 79:18. [PMID: 34971404 DOI: 10.1007/s00018-021-04075-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/08/2021] [Accepted: 10/14/2021] [Indexed: 10/19/2022]
Abstract
In mammalian male meiosis, the heterologous X and Y chromosomes remain unsynapsed and, as a result, are subject to meiotic sex chromosome inactivation (MSCI). MSCI is required for the successful completion of spermatogenesis. Following the initiation of MSCI, the X and Y chromosomes undergo various epigenetic modifications and are transformed into a nuclear body termed the XY body. Here, we review the mechanisms underlying the initiation of two essential, sequential processes in meiotic prophase I: MSCI and XY-body formation. The initiation of MSCI is directed by the action of DNA damage response (DDR) pathways; downstream of the DDR, unique epigenetic states are established, leading to the formation of the XY body. Accumulating evidence suggests that MSCI and subsequent XY-body formation may be driven by phase separation, a physical process that governs the formation of membraneless organelles and other biomolecular condensates. Thus, here we gather literature-based evidence to explore a phase separation hypothesis for the initiation of MSCI and the formation of the XY body.
Collapse
Affiliation(s)
- Kris G Alavattam
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, WA, 98109, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, 98109, USA.,Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - So Maezawa
- Faculty of Science and Technology, Department of Applied Biological Science, Tokyo University of Science, Chiba, 278-8510, Japan
| | - Paul R Andreassen
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Satoshi H Namekawa
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA, 95616, USA.
| |
Collapse
|
6
|
Gantchev J, Martínez Villarreal A, Gunn S, Zetka M, Ødum N, Litvinov IV. The ectopic expression of meiCT genes promotes meiomitosis and may facilitate carcinogenesis. Cell Cycle 2020; 19:837-854. [PMID: 32223693 DOI: 10.1080/15384101.2020.1743902] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cancer meiomitosis is defined as the concurrent activation of both mitotic and meiotic machineries in neoplastic cells that confer a selective advantage together with increased genomic instability. MeiCT (meiosis-specific cancer/testis) genes that perform specialized functions in the germline events required for the first meiotic division are ectopically expressed in several cancers. Here we describe the expression profiles of meiCT genes and proteins across a number of cancers and review the proposed mechanisms that increase aneuploidy and elicit reduction division in polyploid cells. These mechanisms are centered on the overexpression and function of meiCT proteins in cancers under various conditions that includes a response to genotoxic stress. Since meiCT genes are transcriptionally repressed in somatic cells, their target offers a promising therapeutic approach with limited toxicity to healthy tissues. Throughout the review, we provide a detailed description of the roles for each gene in the context of meiosis and we discuss proposed functions and outcomes resulting from their ectopic reactivation in cancer.
Collapse
Affiliation(s)
- Jennifer Gantchev
- Division of Dermatology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | | | - Scott Gunn
- Division of Dermatology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Monique Zetka
- Department of Biology, McGill University, Montreal, QC, Canada
| | - Neils Ødum
- Department of Microbiology and Immunology, The University of Copenhagen, Copenhagen, Denmark
| | - Ivan V Litvinov
- Division of Dermatology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| |
Collapse
|
7
|
Primordial follicle reserve, DNA damage and macrophage infiltration in the ovaries of the long-living Ames dwarf mice. Exp Gerontol 2020; 132:110851. [PMID: 31987917 DOI: 10.1016/j.exger.2020.110851] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 01/07/2023]
Abstract
The aim of this study was to evaluate the effect of growth hormone (GH) deficiency in primordial follicle reserve, DNA damage and macrophage infiltration in the ovaries of young mice. Ovaries from six-month-old GH-deficient Ames Dwarf (df/df) and Normal (N/df) mice were used. The number of primordial follicles was higher in df/df mice (p = 0.0026). Also, df/df mice had a lower number of primary (p = 0.023), secondary (p = 0.0052) and tertiary (p = 0.019) follicles. These findings indicate a slower rate of primordial follicle activation in df/df mice. Female df/df mice had decreased γH2AX foci intensity in oocytes of primordial (p = 0.015) and primary (p = 0.0004) follicles compared to N/df mice. Also, df/df mice had reduced γH2AX intensity in granulosa cells of primordial (p = 0.0002) and primary (p < 0.0001) follicles. Overall, this indicate to us that df/df mice accumulate less DNA damage in the ovarian reserve compared to N/df mice. Additionally, macrophage infiltration was also reduced in ovaries of df/df mice compared to N/df mice (p = 0.033). Interestingly, df/df mice had a reduced number of granulosa cells around primordial (p = 0.0024) and primary (p = 0.007) follicles compared to N/df mice. Also, df/df mice had a small diameter of primordial follicle nuclei (p = 0.0093), secondary follicle oocyte (p = 0.046) and tertiary follicle (p = 0.012). This points to the role of granulosa cell proliferation and oocyte growth for primordial follicle activation. The current study points to the role of the GH/IGF-I axis in extending lifespan of reproductive health, along with maintenance of oocyte DNA integrity and reduced ovarian inflammation.
Collapse
|
8
|
Dokshin GA, Davis GM, Sawle AD, Eldridge MD, Nicholls PK, Gourley TE, Romer KA, Molesworth LW, Tatnell HR, Ozturk AR, de Rooij DG, Hannon GJ, Page DC, Mello CC, Carmell MA. GCNA Interacts with Spartan and Topoisomerase II to Regulate Genome Stability. Dev Cell 2020; 52:53-68.e6. [PMID: 31839538 PMCID: PMC7227305 DOI: 10.1016/j.devcel.2019.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/14/2019] [Accepted: 11/13/2019] [Indexed: 12/22/2022]
Abstract
GCNA proteins are expressed across eukarya in pluripotent cells and have conserved functions in fertility. GCNA homologs Spartan (DVC-1) and Wss1 resolve DNA-protein crosslinks (DPCs), including Topoisomerase-DNA adducts, during DNA replication. Here, we show that GCNA mutants in mouse and C. elegans display defects in genome maintenance including DNA damage, aberrant chromosome condensation, and crossover defects in mouse spermatocytes and spontaneous genomic rearrangements in C. elegans. We show that GCNA and topoisomerase II (TOP2) physically interact in both mice and worms and colocalize on condensed chromosomes during mitosis in C. elegans embryos. Moreover, C. elegans gcna-1 mutants are hypersensitive to TOP2 poison. Together, our findings support a model in which GCNA provides genome maintenance functions in the germline and may do so, in part, by promoting the resolution of TOP2 DPCs.
Collapse
Affiliation(s)
- Gregoriy A Dokshin
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Gregory M Davis
- School of Health and Life Sciences, Federation University, VIC 3841, Australia
| | - Ashley D Sawle
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK
| | - Matthew D Eldridge
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK
| | | | - Taylin E Gourley
- School of Health and Life Sciences, Federation University, VIC 3841, Australia
| | - Katherine A Romer
- Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA; Computational and Systems Biology Program, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Luke W Molesworth
- School of Health and Life Sciences, Federation University, VIC 3841, Australia
| | - Hannah R Tatnell
- School of Health and Life Sciences, Federation University, VIC 3841, Australia
| | - Ahmet R Ozturk
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Dirk G de Rooij
- Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA; Reproductive Biology Group, Division of Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584, the Netherlands; Center for Reproductive Medicine, Academic Medical Center, University of Amsterdam 1105, the Netherlands
| | - Gregory J Hannon
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - David C Page
- Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - Craig C Mello
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA; Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Michelle A Carmell
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA; Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
| |
Collapse
|
9
|
Qi HZ, Wang WZ, He JY, Ma Y, Xiao FZ, He SY. Antioxidative system of Deinococcus radiodurans. Res Microbiol 2019; 171:45-54. [PMID: 31756434 DOI: 10.1016/j.resmic.2019.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 10/31/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
Deinococcus radiodurans is famous for its extreme resistance to various stresses such as ionizing radiation (IR), desiccation and oxidative stress. The underlying mechanism of exceptional resistance of this robust bacterium still remained unclear. However, the antioxidative system of D. radiodurans has been considered to be the determinant factor for its unparalleled resistance and protects the proteome during stress, then the DNA repair system and metabolic system exert their functions to restore the cell to normal physiological state. The antioxidative system not only equipped with the common reactive oxygen species (ROS) scavenging enzymes (e.g., catalase and superoxide dismutase) but also armed with a variety of non-enzyme antioxidants (e.g., carotenoids and manganese species). And the small manganese complexes play an important role in the antioxidative system of D. radiodurans. Recent studies have characterized several regulators (e.g., PprI and PprM) in D. radiodurans, which play critical roles in the protection of the bacteria from various stresses. In this review, we offer a panorama of the progress regarding the characteristics of the antioxidative system in D. radiodurans and its application in the future.
Collapse
Affiliation(s)
- Hui-Zhou Qi
- Institute of Biochemistry and Molecular Biology, Hengyang Medical College, University of South China, Hengyang, 421001, China; Function Laboratory Center, Hengyang Medical College, University of South China, Hengyang, 421001, China; Hengyang Key Laboratory for Biological Effects of Nuclear Radiation, University of South China, Hengyang, 421001, China
| | - Wu-Zhou Wang
- Institute of Biochemistry and Molecular Biology, Hengyang Medical College, University of South China, Hengyang, 421001, China; Hengyang Key Laboratory for Biological Effects of Nuclear Radiation, University of South China, Hengyang, 421001, China
| | - Jun-Yan He
- Institute of Biochemistry and Molecular Biology, Hengyang Medical College, University of South China, Hengyang, 421001, China; Hengyang Key Laboratory for Biological Effects of Nuclear Radiation, University of South China, Hengyang, 421001, China
| | - Yun Ma
- Institute of Biochemistry and Molecular Biology, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Fang-Zhu Xiao
- Hengyang Key Laboratory for Biological Effects of Nuclear Radiation, University of South China, Hengyang, 421001, China
| | - Shu-Ya He
- Institute of Biochemistry and Molecular Biology, Hengyang Medical College, University of South China, Hengyang, 421001, China; Hengyang Key Laboratory for Biological Effects of Nuclear Radiation, University of South China, Hengyang, 421001, China.
| |
Collapse
|
10
|
Coticchio G, Dal Canto M, Guglielmo MC, Albertini DF, Mignini Renzini M, Merola M, Lain M, Sottocornola M, De Ponti E, Fadini R. Double-strand DNA breaks and repair response in human immature oocytes and their relevance to meiotic resumption. J Assist Reprod Genet 2015; 32:1509-16. [PMID: 26238391 PMCID: PMC4615920 DOI: 10.1007/s10815-015-0547-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/21/2015] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Only 50-60 % of immature human oocytes attain the mature stage in vitro. Such a deficiency may be a reflection of inadequate conditions of in vitro maturation (IVM) or a manifestation of intrinsic oocyte defects. In the present study, we explored the possibility that the DNA of immature oocytes may be damaged and that such a condition, or inability to trigger a repair action, is associated to germinal vesicle (GV) arrest. METHODS Immature oocytes (GV-stage oocytes) were obtained from women undergoing stimulated (Stim-C) or IVM (IVM-C) cycles. GV oocytes obtained from stimulated cycles were fixed for successive analysis either after recovery (T0) or following 30 h (T30) of culture if still arrested at the GV stage. Oocytes retrieved in IVM cycles were used only if they were found arrested at the GV stage after 30 h (T30) of culture. All oocytes were fixed and stained to detect chromatin and actin. They were also assessed for positivity to γH2AX and Rad51, markers revealing the presence of double-strand DNA breaks and the activation of a DNA repair response, respectively. Labelled oocytes were analysed using a Leica TCS SP2 laser scanning confocal microscope. RESULTS In Stim-C oocytes, γH2AX positivity was 47.5 and 81.5 % in the T0 and T30 groups, respectively (P = 0.003), while γH2AX-positive oocytes were 58.3 % in the IVM-C T30 group (Stim-C T0 vs. IVM-C T30, P = 0.178; Stim-C T30 vs. IVM-C T30, P = 0.035). Positivity for nuclear staining to Rad51 occurred in 42.1 and 74.1 % of Stim-C in the T0 and T30 subgroups, respectively (T = 0.006), while 66.7 % of IVM-C T30 oocytes resulted positive for a DNA repair response (Stim-C T0 vs. IVM-C T30, P = 0.010; Stim-C T30 vs. IVM-C T30, P = 0.345). CONCLUSIONS The present data document the existence of double-strand DNA breaks (DSBs) in human immature oocytes. Also, they are consistent with the hypothesis that insults to DNA integrity may be an important factor affecting meiotic resumption.
Collapse
Affiliation(s)
- Giovanni Coticchio
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy.
| | - Mariabeatrice Dal Canto
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy
| | | | - David F Albertini
- Center for Human Reproduction, New York, NY, USA
- Department of Molecular and Integrative Physiology, University of Kansas, Kansas City, USA
| | - Mario Mignini Renzini
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy
| | - Maria Merola
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy
| | - Monia Lain
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy
| | - Manuela Sottocornola
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy
| | - Elena De Ponti
- Department of Medical Physics, San Gerardo Hospital, Monza, Italy
| | - Rubens Fadini
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy
| |
Collapse
|
11
|
Pacheco S, Marcet-Ortega M, Lange J, Jasin M, Keeney S, Roig I. The ATM signaling cascade promotes recombination-dependent pachytene arrest in mouse spermatocytes. PLoS Genet 2015; 11:e1005017. [PMID: 25768017 PMCID: PMC4358828 DOI: 10.1371/journal.pgen.1005017] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 01/22/2015] [Indexed: 11/29/2022] Open
Abstract
Most mutations that compromise meiotic recombination or synapsis in mouse spermatocytes result in arrest and apoptosis at the pachytene stage of the first meiotic prophase. Two main mechanisms are thought to trigger arrest: one independent of the double-strand breaks (DSBs) that initiate meiotic recombination, and another activated by persistent recombination intermediates. Mechanisms underlying the recombination-dependent arrest response are not well understood, so we sought to identify factors involved by examining mutants deficient for TRIP13, a conserved AAA+ ATPase required for the completion of meiotic DSB repair. We find that spermatocytes with a hypomorphic Trip13 mutation (Trip13mod/mod) arrest with features characteristic of early pachynema in wild type, namely, fully synapsed chromosomes without incorporation of the histone variant H1t into chromatin. These cells then undergo apoptosis, possibly in response to the arrest or in response to a defect in sex body formation. However, TRIP13-deficient cells that additionally lack the DSB-responsive kinase ATM progress further, reaching an H1t-positive stage (i.e., similar to mid/late pachynema in wild type) despite the presence of unrepaired DSBs. TRIP13-deficient spermatocytes also progress to an H1t-positive stage if ATM activity is attenuated by hypomorphic mutations in Mre11 or Nbs1 or by elimination of the ATM-effector kinase CHK2. These mutant backgrounds nonetheless experience an apoptotic block to further spermatogenic progression, most likely caused by failure to form a sex body. DSB numbers are elevated in Mre11 and Nbs1 hypomorphs but not Chk2 mutants, thus delineating genetic requirements for the ATM-dependent negative feedback loop that regulates DSB numbers. The findings demonstrate for the first time that ATM-dependent signaling enforces the normal pachytene response to persistent recombination intermediates. Our work supports the conclusion that recombination defects trigger spermatocyte arrest via pathways than are genetically distinct from sex body failure-promoted apoptosis and confirm that the latter can function even when recombination-dependent arrest is inoperative. Implications of these findings for understanding the complex relationships between spermatocyte arrest and apoptosis are discussed. Meiosis is the specialized cell division by which haploid cells are produced. As germ cells enter the first meiotic prophase, programmed double-stranded breaks (DSBs) are formed throughout the genome. Repair of these DSBs by homologous recombination is crucial for proper segregation of homologous chromosomes at the end of the first meiotic division, and thus, for the production of haploid gametes. Moreover, failure to correctly repair these DSBs can have deleterious effects on the genomic integrity of offspring. To ensure that meiocytes that fail to repair meiotic DSBs do not complete meiosis, recombination is tightly controlled. However, the signaling pathway(s) tying meiotic recombination to meiotic progression in mouse spermatocytes is not known. We report here that the ATM-signaling pathway, composed of the MRE11 complex, ATM and CHK2, is responsible for activation of the recombination-dependent arrest that occurs in Trip13 mutant mouse spermatocytes, which accumulate unrepaired DSBs during meiotic prophase.
Collapse
Affiliation(s)
- Sarai Pacheco
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
- Cytology and Histology Unit, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Marina Marcet-Ortega
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
- Cytology and Histology Unit, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Julian Lange
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- * E-mail: (SK); (IR)
| | - Ignasi Roig
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
- Cytology and Histology Unit, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
- * E-mail: (SK); (IR)
| |
Collapse
|
12
|
Coticchio G, Dal Canto M, Mignini Renzini M, Guglielmo MC, Brambillasca F, Turchi D, Novara PV, Fadini R. Oocyte maturation: gamete-somatic cells interactions, meiotic resumption, cytoskeletal dynamics and cytoplasmic reorganization. Hum Reprod Update 2015; 21:427-54. [PMID: 25744083 DOI: 10.1093/humupd/dmv011] [Citation(s) in RCA: 321] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 02/11/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND In a growth phase occurring during most of folliculogenesis, the oocyte produces and accumulates molecules and organelles that are fundamental for the development of the preimplantation embryo. At ovulation, growth is followed by a phase of maturation that, although confined within a short temporal window, encompasses modifications of the oocyte chromosome complement and rearrangements of cytoplasmic components that are crucial for the achievement of developmental competence. Cumulus cells (CCs) are central to the process of maturation, providing the oocyte with metabolic support and regulatory cues. METHODS PubMed was used to search the MEDLINE database for peer-reviewed original articles and reviews concerning oocyte maturation in mammals. Searches were performed adopting 'oocyte' and 'maturation' as main terms, in association with other keywords expressing concepts relevant to the subject. The most relevant publications, i.e. those concerning major phenomena occurring during oocyte maturation in established experimental models and the human species, were assessed and discussed critically to offer a comprehensive description of the process of oocyte maturation. RESULTS By applying the above described search criteria, 6165 publications were identified, of which 543 were review articles. The number of publications increased steadily from 1974 (n = 7) to 2013 (n = 293). In 2014, from January to the time of submission of this manuscript, 140 original manuscripts and reviews were published. The studies selected for this review extend previous knowledge and shed new and astounding knowledge on oocyte maturation. It has long been known that resumption of meiosis and progression to the metaphase II stage is intrinsic to oocyte maturation, but novel findings have revealed that specific chromatin configurations are indicative of a propensity of the oocyte to resume the meiotic process and acquire developmental competence. Recently, genetic integrity has also been characterized as a factor with important implications for oocyte maturation and quality. Changes occurring in the cytoplasmic compartment are equally fundamental. Microtubules, actin filaments and chromatin not only interact to finalize chromosome segregation, but also crucially co-operate to establish cell asymmetry. This allows polar body extrusion to be accomplished with minimal loss of cytoplasm. The cytoskeleton also orchestrates the rearrangement of organelles in preparation for fertilization. For example, during maturation the distribution of the endoplasmic reticulum undergoes major modifications guided by microtubules and microfilaments to make the oocyte more competent in the generation of intracellular Ca(2+) oscillations that are pivotal for triggering egg activation. Cumulus cells are inherent to the process of oocyte maturation, emitting regulatory signals via direct cell-to-cell contacts and paracrine factors. In addition to nurturing the oocyte with key metabolites, CCs regulate meiotic resumption and modulate the function of the oocyte cytoskeleton. CONCLUSIONS Although the importance of oocyte maturation for the achievement of female meiosis has long been recognized, until recently much less was known of the significance of this process in relation to other fundamental developmental events. Studies on chromatin dynamics and integrity have extended our understanding of female meiosis. Concomitantly, cytoskeletal and organelle changes and the ancillary role of CCs have been better appreciated. This is expected to inspire novel concepts and advances in assisted reproduction technologies, such as the development of novel in vitro maturation systems and the identification of biomarkers of oocyte quality.
Collapse
Affiliation(s)
- Giovanni Coticchio
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| | - Mariabeatrice Dal Canto
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| | - Mario Mignini Renzini
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| | - Maria Cristina Guglielmo
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| | - Fausta Brambillasca
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| | - Diana Turchi
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| | - Paola Vittoria Novara
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| | - Rubens Fadini
- Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi 24, 20900 Monza, Italy
| |
Collapse
|
13
|
Vernet N, Mahadevaiah SK, Yamauchi Y, Decarpentrie F, Mitchell MJ, Ward MA, Burgoyne PS. Mouse Y-linked Zfy1 and Zfy2 are expressed during the male-specific interphase between meiosis I and meiosis II and promote the 2nd meiotic division. PLoS Genet 2014; 10:e1004444. [PMID: 24967676 PMCID: PMC4072562 DOI: 10.1371/journal.pgen.1004444] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Accepted: 05/02/2014] [Indexed: 11/19/2022] Open
Abstract
Mouse Zfy1 and Zfy2 encode zinc finger transcription factors that map to the short arm of the Y chromosome (Yp). They have previously been shown to promote meiotic quality control during pachytene (Zfy1 and Zfy2) and at the first meiotic metaphase (Zfy2). However, from these previous studies additional roles for genes encoded on Yp during meiotic progression were inferred. In order to identify these genes and investigate their function in later stages of meiosis, we created three models with diminishing Yp and Zfy gene complements (but lacking the Y-long-arm). Since the Y-long-arm mediates pairing and exchange with the X via their pseudoautosomal regions (PARs) we added a minute PAR-bearing X chromosome derivative to enable formation of a sex bivalent, thus avoiding Zfy2-mediated meiotic metaphase I (MI) checkpoint responses to the unpaired (univalent) X chromosome. Using these models we obtained definitive evidence that genetic information on Yp promotes meiosis II, and by transgene addition identified Zfy1 and Zfy2 as the genes responsible. Zfy2 was substantially more effective and proved to have a much more potent transactivation domain than Zfy1. We previously established that only Zfy2 is required for the robust apoptotic elimination of MI spermatocytes in response to a univalent X; the finding that both genes potentiate meiosis II led us to ask whether there was de novo Zfy1 and Zfy2 transcription in the interphase between meiosis I and meiosis II, and this proved to be the case. X-encoded Zfx was also expressed at this stage and Zfx over-expression also potentiated meiosis II. An interphase between the meiotic divisions is male-specific and we previously hypothesised that this allows meiosis II critical X and Y gene reactivation following sex chromosome silencing in meiotic prophase. The interphase transcription and meiosis II function of Zfx, Zfy1 and Zfy2 validate this hypothesis. The mouse Y chromosome genes Zfy1 and Zfy2 were first identified in the late 1980s during the search for the gene on the Y that triggers male development; they encode proteins that regulate the expression of other genes to which they bind via a ‘zinc finger’ domain. We have now discovered that these genes play important roles during spermatogenesis. Zfy2 proved to be essential for the efficient operation of a ‘checkpoint’ during the first meiotic division that identifies and kills cells that would otherwise produce sperm with an unbalanced chromosome set. Female meiosis, which does not have an equivalent checkpoint, generates a significant proportion of eggs with an unbalanced chromosome set. In the present study we show that Zfy2 also has a major role in ensuring that the second meiotic division occurs, with Zfy1 and a related gene, Zfx, on the X chromosome providing some support. In order to fulfil this function all three genes are expressed in the ‘interphase’ stage between the two divisions. In female meiosis there is no interphase stage between the two meiotic divisions but in this case essential functions during the divisions are supported by stored RNAs, so an interphase is not needed.
Collapse
Affiliation(s)
- Nadège Vernet
- MRC National Institute for Medical Research, London, United Kingdom
- Department of functional genomics and cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- * E-mail: ,
| | | | - Yasuhiro Yamauchi
- Institute for Biogenesis Research, University of Hawaii Medical School, Honolulu, Hawaii, United States of America
| | | | - Michael J. Mitchell
- Aix Marseille Université, GMGF, Marseille, France
- Inserm UMR_S 910, Marseille, France
| | - Monika A. Ward
- Institute for Biogenesis Research, University of Hawaii Medical School, Honolulu, Hawaii, United States of America
| | - Paul S. Burgoyne
- MRC National Institute for Medical Research, London, United Kingdom
| |
Collapse
|
14
|
Baumann C, De La Fuente R. Role of polycomb group protein cbx2/m33 in meiosis onset and maintenance of chromosome stability in the Mammalian germline. Genes (Basel) 2014; 2:59-80. [PMID: 22200029 PMCID: PMC3244348 DOI: 10.3390/genes2010059] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Polycomb group proteins (PcG) are major epigenetic regulators, essential for establishing heritable expression patterns of developmental control genes. The mouse PcG family member M33/Cbx2 (Chromobox homolog protein 2) is a component of the Polycomb-Repressive Complex 1 (PRC1). Targeted deletion of Cbx2/M33 in mice results in homeotic transformations of the axial skeleton, growth retardation and male-to-female sex reversal. In this study, we tested whether Cbx2 is involved in the control of chromatin remodeling processes during meiosis. Our analysis revealed sex reversal in 28.6% of XY(-/-) embryos, in which a hypoplastic testis and a contralateral ovary were observed in close proximity to the kidney, while the remaining male mutant fetuses exhibited bilateral testicular hypoplasia. Notably, germ cells recovered from Cbx2((XY-/-)) testes on day 18.5 of fetal development exhibited premature meiosis onset with synaptonemal complex formation suggesting a role for Cbx2 in the control of meiotic entry in male germ cells. Mutant females exhibited small ovaries with significant germ cell loss and a high proportion of oocytes with abnormal synapsis and non-homologous interactions at the pachytene stage as well as formation of univalents at diplotene. These defects were associated with failure to resolve DNA double strand breaks marked by persistent γH2AX and Rad51 foci at the late pachytene stage. Importantly, two factors required for meiotic silencing of asynapsed chromatin, ubiquitinated histone H2A (ubH2A) and the chromatin remodeling protein BRCA1, co-localized with fully synapsed chromosome axes in the majority of Cbx2((-/-)) oocytes. These results provide novel evidence that Cbx2 plays a critical and previously unrecognized role in germ cell viability, meiosis onset and homologous chromosome synapsis in the mammalian germline.
Collapse
Affiliation(s)
- Claudia Baumann
- Female Germ Cell Biology Group, Department of Clinical Studies, Center for Animal Transgenesis and Germ Cell Research, School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA; E-Mail:
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA 30602, USA
| | - Rabindranath De La Fuente
- Female Germ Cell Biology Group, Department of Clinical Studies, Center for Animal Transgenesis and Germ Cell Research, School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA; E-Mail:
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA 30602, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-706-542-5864; Fax: +1-706-542-3015
| |
Collapse
|
15
|
The ATM-mediated DNA-damage response. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
16
|
MEIOB targets single-strand DNA and is necessary for meiotic recombination. PLoS Genet 2013; 9:e1003784. [PMID: 24068956 PMCID: PMC3778009 DOI: 10.1371/journal.pgen.1003784] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 07/25/2013] [Indexed: 11/19/2022] Open
Abstract
Meiotic recombination is a mandatory process for sexual reproduction. We identified a protein specifically implicated in meiotic homologous recombination that we named: meiosis specific with OB domain (MEIOB). This protein is conserved among metazoan species and contains single-strand DNA binding sites similar to those of RPA1. Our studies in vitro revealed that both recombinant and endogenous MEIOB can be retained on single-strand DNA. Those in vivo demonstrated the specific expression of Meiob in early meiotic germ cells and the co-localization of MEIOB protein with RPA on chromosome axes. MEIOB localization in Dmc1 (-/-) spermatocytes indicated that it accumulates on resected DNA. Homologous Meiob deletion in mice caused infertility in both sexes, due to a meiotic arrest at a zygotene/pachytene-like stage. DNA double strand break repair and homologous chromosome synapsis were impaired in Meiob (-/-) meiocytes. Interestingly MEIOB appeared to be dispensable for the initial loading of recombinases but was required to maintain a proper number of RAD51 and DMC1 foci beyond the zygotene stage. In light of these findings, we propose that RPA and this new single-strand DNA binding protein MEIOB, are essential to ensure the proper stabilization of recombinases which is required for successful homology search and meiotic recombination.
Collapse
|
17
|
Carroll J, Marangos P. The DNA damage response in mammalian oocytes. Front Genet 2013; 4:117. [PMID: 23805152 PMCID: PMC3690358 DOI: 10.3389/fgene.2013.00117] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/03/2013] [Indexed: 01/11/2023] Open
Abstract
DNA damage is one of the most common insults that challenge all cells. To cope, an elaborate molecular and cellular response has evolved to sense, respond to and correct the damage. This allows the maintenance of DNA fidelity essential for normal cell viability and the prevention of genomic instability that can lead to tumor formation. In the context of oocytes, the impact of DNA damage is not one of tumor formation but of the maintenance of fertility. Mammalian oocytes are particularly vulnerable to DNA damage because physiologically they may lie dormant in the ovary for many years (>40 in humans) until they receive the stimulus to grow and acquire the competence to become fertilized. The implication of this is that in some organisms, such as humans, oocytes face the danger of cumulative genetic damage for decades. Thus, the ability to detect and repair DNA damage is essential to maintain the supply of oocytes necessary for reproduction. Therefore, failure to confront DNA damage in oocytes could cause serious anomalies in the embryo that may be propagated in the form of mutations to the next generation allowing the appearance of hereditary disease. Despite the potential impact of DNA damage on reproductive capacity and genetic fidelity of embryos, the mechanisms available to the oocyte for monitoring and repairing such insults have remained largely unexplored until recently. Here, we review the different aspects of the response to DNA damage in mammalian oocytes. Specifically, we address the oocyte DNA damage response from embryonic life to adulthood and throughout oocyte development.
Collapse
Affiliation(s)
- John Carroll
- School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University Melbourne, VIC, Australia
| | | |
Collapse
|
18
|
Blanco-Rodríguez J. Programmed phosphorylation of histone H2AX precedes a phase of DNA double-strand break-independent synapsis in mouse meiosis. Reproduction 2012; 144:699-712. [PMID: 23035256 DOI: 10.1530/rep-12-0326] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Accurate homologue synapsis during meiosis is essential for faithful chromosome segregation and formation of viable gametes. The finding of Spo11-dependent gamma-H2AX (γH2AX) formation during leptotene and data on mutant mice have led to the notion that synapsis in mammals depends on meiotic DNA double-stranded break (DSB) repair. A second wave of ataxia telangiectasia mutated (ATM) and Rad3-related (ATR)-dependent γH2AX formation has been observed in Atm-null mice during zygotene, suggesting that this wave of phosphorylation also occurs in normal mice. Here I aimed to confirm and to analyse in deep this wave of phosphorylation. Immunostaining of spread spermatocytes shows that γH2AX accumulates on the short last axis stretches to pair. This accumulation appears within all the nuclei undergoing a specific step of late zygotene and disappears from every spermatocyte immediately after pairing completion. This γH2AX signal co-localises with ATR, is Spo11-independent and does not co-localise with free DNA 3'-end labelling. I conclude that ATR/γH2AX asynapsis signalling at the end of zygotene belongs to a physiologically programmed pathway operating at a specific meiotic step, and I propose that this pathway is involved in the triggering of a phase of DSB-independent chromosome pairing that leads to synapsis completion in normal mouse meiosis.
Collapse
Affiliation(s)
- Josefa Blanco-Rodríguez
- Departamento de Biología Celular, Facultad de Medicina, Universidad de Valladolid, Ramón y Cajal 7, 47005 Valladolid, Spain.
| |
Collapse
|
19
|
Sex chromosome inactivation in germ cells: emerging roles of DNA damage response pathways. Cell Mol Life Sci 2012; 69:2559-72. [PMID: 22382926 DOI: 10.1007/s00018-012-0941-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 02/09/2012] [Accepted: 02/13/2012] [Indexed: 10/28/2022]
Abstract
Sex chromosome inactivation in male germ cells is a paradigm of epigenetic programming during sexual reproduction. Recent progress has revealed the underlying mechanisms of sex chromosome inactivation in male meiosis. The trigger of chromosome-wide silencing is activation of the DNA damage response (DDR) pathway, which is centered on the mediator of DNA damage checkpoint 1 (MDC1), a binding partner of phosphorylated histone H2AX (γH2AX). This DDR pathway shares features with the somatic DDR pathway recognizing DNA replication stress in the S phase. Additionally, it is likely to be distinct from the DDR pathway that recognizes meiosis-specific double-strand breaks. This review article extensively discusses the underlying mechanism of sex chromosome inactivation.
Collapse
|
20
|
De La Fuente R, Baumann C, Viveiros MM. Role of ATRX in chromatin structure and function: implications for chromosome instability and human disease. Reproduction 2011; 142:221-34. [PMID: 21653732 PMCID: PMC3253860 DOI: 10.1530/rep-10-0380] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Functional differentiation of chromatin structure is essential for the control of gene expression, nuclear architecture, and chromosome stability. Compelling evidence indicates that alterations in chromatin remodeling proteins play an important role in the pathogenesis of human disease. Among these, α-thalassemia mental retardation X-linked protein (ATRX) has recently emerged as a critical factor involved in heterochromatin formation at mammalian centromeres and telomeres as well as facultative heterochromatin on the murine inactive X chromosome. Mutations in human ATRX result in an X-linked neurodevelopmental condition with various degrees of gonadal dysgenesis (ATRX syndrome). Patients with ATRX syndrome may exhibit skewed X chromosome inactivation (XCI) patterns, and ATRX-deficient mice exhibit abnormal imprinted XCI in the trophoblast cell line. Non-random or skewed XCI can potentially affect both the onset and severity of X-linked disease. Notably, failure to establish epigenetic modifications associated with the inactive X chromosome (Xi) results in several conditions that exhibit genomic and chromosome instability such as fragile X syndrome as well as cancer development. Insight into the molecular mechanisms of ATRX function and its interacting partners in different tissues will no doubt contribute to our understanding of the pathogenesis of ATRX syndrome as well as the epigenetic origins of aneuploidy. In turn, this knowledge will be essential for the identification of novel drug targets and diagnostic tools for cancer progression as well as the therapeutic management of global epigenetic changes commonly associated with malignant neoplastic transformation.
Collapse
Affiliation(s)
- Rabindranath De La Fuente
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, USA.
| | | | | |
Collapse
|
21
|
Genetic evidence that synaptonemal complex axial elements govern recombination pathway choice in mice. Genetics 2011; 189:71-82. [PMID: 21750255 DOI: 10.1534/genetics.111.130674] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chiasmata resulting from interhomolog recombination are critical for proper chromosome segregation at meiotic metaphase I, thus preventing aneuploidy and consequent deleterious effects. Recombination in meiosis is driven by programmed induction of double strand breaks (DSBs), and the repair of these breaks occurs primarily by recombination between homologous chromosomes, not sister chromatids. Almost nothing is known about the basis for recombination partner choice in mammals. We addressed this problem using a genetic approach. Since meiotic recombination is coupled with synaptonemal complex (SC) morphogenesis, we explored the role of axial elements--precursors to the lateral element in the mature SC--in recombination partner choice, DSB repair pathways, and checkpoint control. Female mice lacking the SC axial element protein SYCP3 produce viable, but often aneuploid, oocytes. We describe genetic studies indicating that while DSB-containing Sycp3-/- oocytes can be eliminated efficiently, those that survive have completed repair before the execution of an intact DNA damage checkpoint. We find that the requirement for DMC1 and TRIP13, proteins normally essential for recombination repair of meiotic DSBs, is substantially bypassed in Sycp3 and Sycp2 mutants. This bypass requires RAD54, a functionally conserved protein that promotes intersister recombination in yeast meiosis and mammalian mitotic cells. Immunocytological and genetic studies indicated that the bypass in Sycp3-/- Dmc1-/- oocytes was linked to increased DSB repair. These experiments lead us to hypothesize that axial elements mediate the activities of recombination proteins to favor interhomolog, rather than intersister recombinational repair of genetically programmed DSBs in mice. The elimination of this activity in SYCP3- or SYCP2-deficient oocytes may underlie the aneuploidy in derivative mouse embryos and spontaneous abortions in women.
Collapse
|
22
|
Abstract
Deinococcus radiodurans is a robust bacterium best known for its capacity to repair massive DNA damage efficiently and accurately. It is extremely resistant to many DNA-damaging agents, including ionizing radiation and UV radiation (100 to 295 nm), desiccation, and mitomycin C, which induce oxidative damage not only to DNA but also to all cellular macromolecules via the production of reactive oxygen species. The extreme resilience of D. radiodurans to oxidative stress is imparted synergistically by an efficient protection of proteins against oxidative stress and an efficient DNA repair mechanism, enhanced by functional redundancies in both systems. D. radiodurans assets for the prevention of and recovery from oxidative stress are extensively reviewed here. Radiation- and desiccation-resistant bacteria such as D. radiodurans have substantially lower protein oxidation levels than do sensitive bacteria but have similar yields of DNA double-strand breaks. These findings challenge the concept of DNA as the primary target of radiation toxicity while advancing protein damage, and the protection of proteins against oxidative damage, as a new paradigm of radiation toxicity and survival. The protection of DNA repair and other proteins against oxidative damage is imparted by enzymatic and nonenzymatic antioxidant defense systems dominated by divalent manganese complexes. Given that oxidative stress caused by the accumulation of reactive oxygen species is associated with aging and cancer, a comprehensive outlook on D. radiodurans strategies of combating oxidative stress may open new avenues for antiaging and anticancer treatments. The study of the antioxidation protection in D. radiodurans is therefore of considerable potential interest for medicine and public health.
Collapse
|
23
|
Baumann C, Daly CM, McDonnell SM, Viveiros MM, De La Fuente R. Chromatin configuration and epigenetic landscape at the sex chromosome bivalent during equine spermatogenesis. Chromosoma 2011; 120:227-44. [PMID: 21274552 PMCID: PMC3100478 DOI: 10.1007/s00412-010-0306-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 12/03/2010] [Accepted: 12/16/2010] [Indexed: 11/24/2022]
Abstract
Pairing of the sex chromosomes during mammalian meiosis is characterized by the formation of a unique heterochromatin structure at the XY body. The mechanisms underlying the formation of this nuclear domain are reportedly highly conserved from marsupials to mammals. In this study, we demonstrate that in contrast to all eutherian species studied to date, partial synapsis of the heterologous sex chromosomes during pachytene stage in the horse is not associated with the formation of a typical macrochromatin domain at the XY body. While phosphorylated histone H2AX (γH2AX) and macroH2A1.2 are present as a diffuse signal over the entire macrochromatin domain in mouse pachytene spermatocytes, γH2AX, macroH2A1.2, and the cohesin subunit SMC3 are preferentially enriched at meiotic sex chromosome cores in equine spermatocytes. Moreover, although several histone modifications associated with this nuclear domain in the mouse such as H3K4me2 and ubH2A are conspicuously absent in the equine XY body, prominent RNA polymerase II foci persist at the sex chromosomes. Thus, the localization of key marker proteins and histone modifications associated with the XY body in the horse differs significantly from all other mammalian systems described. These results demonstrate that the epigenetic landscape and heterochromatinization of the equine XY body might be regulated by alternative mechanisms and that some features of XY body formation may be evolutionary divergent in the domestic horse. We propose equine spermatogenesis as a unique model system for the study of the regulatory networks leading to the epigenetic control of gene expression during XY body formation.
Collapse
Affiliation(s)
- Claudia Baumann
- Female Germ Cell Biology Group, Department of Clinical Studies, University of Pennsylvania, New Bolton Center, Kennett Square, PA 19348, USA
| | | | | | | | | |
Collapse
|
24
|
MacQueen AJ, Hochwagen A. Checkpoint mechanisms: the puppet masters of meiotic prophase. Trends Cell Biol 2011; 21:393-400. [PMID: 21531561 DOI: 10.1016/j.tcb.2011.03.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 03/20/2011] [Accepted: 03/21/2011] [Indexed: 11/30/2022]
Abstract
The coordinated execution of cell cycle processes during meiosis is essential for the production of viable gametes and fertility. Coordination is particularly important during meiotic prophase, when nuclei undergo a dramatic reorganization that requires the precise choreography of chromosome movements, pairing interactions and DNA double-strand break (DSB) repair. Analysis of the underlying regulatory mechanisms has revealed crucial and widespread roles for DNA-damage checkpoint proteins, not only in cell cycle surveillance, but also in controlling many processes uniquely characteristic of meiosis. The resulting regulatory network uses checkpoint machinery to provide an integral coordinating mechanism during every meiotic division and enables cells to safely maintain an error-prone event such as DSB formation as an essential part of the meiotic program.
Collapse
Affiliation(s)
- Amy J MacQueen
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | | |
Collapse
|
25
|
Meiotic homologue alignment and its quality surveillance are controlled by mouse HORMAD1. Nat Cell Biol 2011; 13:599-610. [PMID: 21478856 DOI: 10.1038/ncb2213] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 01/20/2011] [Indexed: 12/14/2022]
Abstract
Meiotic crossover formation between homologous chromosomes (homologues) entails DNA double-strand break (DSB) formation, homology search using DSB ends, and synaptonemal-complex formation coupled with DSB repair. Meiotic progression must be prevented until DSB repair and homologue alignment are completed, to avoid the formation of aneuploid gametes. Here we show that mouse HORMAD1 ensures that sufficient numbers of processed DSBs are available for successful homology search. HORMAD1 is needed for normal synaptonemal-complex formation and for the efficient recruitment of ATR checkpoint kinase activity to unsynapsed chromatin. The latter phenomenon was proposed to be important in meiotic prophase checkpoints in both sexes. Consistent with this hypothesis, HORMAD1 is essential for the elimination of synaptonemal-complex-defective oocytes. Synaptonemal-complex formation results in HORMAD1 depletion from chromosome axes. Thus, we propose that the synaptonemal complex and HORMAD1 are key components of a negative feedback loop that coordinates meiotic progression with homologue alignment: HORMAD1 promotes homologue alignment and synaptonemal-complex formation, and synaptonemal complexes downregulate HORMAD1 function, thereby permitting progression past meiotic prophase checkpoints.
Collapse
|
26
|
Daly MJ, Gaidamakova EK, Matrosova VY, Kiang JG, Fukumoto R, Lee DY, Wehr NB, Viteri GA, Berlett BS, Levine RL. Small-molecule antioxidant proteome-shields in Deinococcus radiodurans. PLoS One 2010; 5:e12570. [PMID: 20838443 PMCID: PMC2933237 DOI: 10.1371/journal.pone.0012570] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 08/09/2010] [Indexed: 01/28/2023] Open
Abstract
For Deinococcus radiodurans and other bacteria which are extremely resistant to ionizing radiation, ultraviolet radiation, and desiccation, a mechanistic link exists between resistance, manganese accumulation, and protein protection. We show that ultrafiltered, protein-free preparations of D. radiodurans cell extracts prevent protein oxidation at massive doses of ionizing radiation. In contrast, ultrafiltrates from ionizing radiation-sensitive bacteria were not protective. The D. radiodurans ultrafiltrate was enriched in Mn, phosphate, nucleosides and bases, and peptides. When reconstituted in vitro at concentrations approximating those in the D. radiodurans cytosol, peptides interacted synergistically with Mn2+ and orthophosphate, and preserved the activity of large, multimeric enzymes exposed to 50,000 Gy, conditions which obliterated DNA. When applied ex vivo, the D. radiodurans ultrafiltrate protected Escherichia coli cells and human Jurkat T cells from extreme cellular insults caused by ionizing radiation. By establishing that Mn2+-metabolite complexes of D. radiodurans specifically protect proteins against indirect damage caused by gamma-rays delivered in vast doses, our findings provide the basis for a new approach to radioprotection and insight into how surplus Mn budgets in cells combat reactive oxygen species.
Collapse
Affiliation(s)
- Michael J. Daly
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- * E-mail: (MJD); (RLL)
| | - Elena K. Gaidamakova
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Vera Y. Matrosova
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Juliann G. Kiang
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Risaku Fukumoto
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Duck-Yeon Lee
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nancy B. Wehr
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Gabriela A. Viteri
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Barbara S. Berlett
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Rodney L. Levine
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (MJD); (RLL)
| |
Collapse
|
27
|
Wojtasz L, Daniel K, Roig I, Bolcun-Filas E, Xu H, Boonsanay V, Eckmann CR, Cooke HJ, Jasin M, Keeney S, McKay MJ, Toth A. Mouse HORMAD1 and HORMAD2, two conserved meiotic chromosomal proteins, are depleted from synapsed chromosome axes with the help of TRIP13 AAA-ATPase. PLoS Genet 2009; 5:e1000702. [PMID: 19851446 PMCID: PMC2758600 DOI: 10.1371/journal.pgen.1000702] [Citation(s) in RCA: 305] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Accepted: 09/25/2009] [Indexed: 11/18/2022] Open
Abstract
Meiotic crossovers are produced when programmed double-strand breaks (DSBs) are repaired by recombination from homologous chromosomes (homologues). In a wide variety of organisms, meiotic HORMA-domain proteins are required to direct DSB repair towards homologues. This inter-homologue bias is required for efficient homology search, homologue alignment, and crossover formation. HORMA-domain proteins are also implicated in other processes related to crossover formation, including DSB formation, inhibition of promiscuous formation of the synaptonemal complex (SC), and the meiotic prophase checkpoint that monitors both DSB processing and SCs. We examined the behavior of two previously uncharacterized meiosis-specific mouse HORMA-domain proteins—HORMAD1 and HORMAD2—in wild-type mice and in mutants defective in DSB processing or SC formation. HORMADs are preferentially associated with unsynapsed chromosome axes throughout meiotic prophase. We observe a strong negative correlation between SC formation and presence of HORMADs on axes, and a positive correlation between the presumptive sites of high checkpoint-kinase ATR activity and hyper-accumulation of HORMADs on axes. HORMADs are not depleted from chromosomes in mutants that lack SCs. In contrast, DSB formation and DSB repair are not absolutely required for depletion of HORMADs from synapsed axes. A simple interpretation of these findings is that SC formation directly or indirectly promotes depletion of HORMADs from chromosome axes. We also find that TRIP13 protein is required for reciprocal distribution of HORMADs and the SYCP1/SC-component along chromosome axes. Similarities in mouse and budding yeast meiosis suggest that TRIP13/Pch2 proteins have a conserved role in establishing mutually exclusive HORMAD-rich and synapsed chromatin domains in both mouse and yeast. Taken together, our observations raise the possibility that involvement of meiotic HORMA-domain proteins in the regulation of homologue interactions is conserved in mammals. Generation of haploid gametes in most organisms requires that homologues become connected via crossovers during meiosis. Efficient formation of crossovers depends on HORMA-domain proteins in diverse taxa. These proteins ensure that programmed meiotic DSBs are preferentially repaired from homologues, rather than from sister chromatids. This inter-homologue bias is crucial for homology search and crossovers formation. HORMA-domain proteins have been also implicated in DSB formation, in suppression of synaptonemal complex formation between non-homologous chromosomes, and in the meiotic prophase checkpoint that monitors DSB repair. Despite the importance of HORMA-domain proteins in various organisms, a role for these proteins in mammalian meiosis hasn't been reported. We examined the behaviour of meiotic mouse HORMA-domain proteins—HORMAD1 and HORMAD2—in wild-type and meiotic mutants. HORMAD1/2 preferentially accumulate on unsynapsed chromosome axes. Our data suggest that HORMAD1/2 depletion from chromosomes is a response to synaptonemal complex formation and it that is a conserved process supported by TRIP13/Pch2 AAA-ATPase. Assuming that HORMA-domain functions are conserved in mammals, we speculate that depletion of HORMADs from axes might contribute to the down-regulation of inter-homologue bias and the prophase checkpoint once homology search is completed and synaptonemal complexes form between aligned homologues.
Collapse
Affiliation(s)
- Lukasz Wojtasz
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Katrin Daniel
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Ignasi Roig
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | | | - Huiling Xu
- Divisions of Radiation Oncology and Research, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Verawan Boonsanay
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | | | - Howard J. Cooke
- Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
- Howard Hughes Medical Institute, New York, New York, United States of America
| | - Michael J. McKay
- Department of Radiation Oncology, Australian National University and the Canberra Hospital, Canberra, Australian Capital Territory, Australia
| | - Attila Toth
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
- * E-mail:
| |
Collapse
|
28
|
Genome-wide analysis of recombination machinery for spliceosomal introns gain. Mol Biol Rep 2009; 37:1551-7. [PMID: 19449167 DOI: 10.1007/s11033-009-9557-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Accepted: 04/30/2009] [Indexed: 10/20/2022]
Abstract
What caused spliceosomal introns gain remains an unsolved problem. To this, defining what spliceosomal introns arise from is critical. Here, the introns density of the genomes is calculated for four species, indicating:(1) sex chromosomes in mammals have lower intron densities, (2) despite that, the proportion of UTRs (untranslated regions) with introns in sex chromosomes is higher than other ones, and (3) AT content of introns is more similar to that of intergenic regions when these regions comprise the majority of a chromosome, and more similar to that of exons, when exons are the majority of the chromosome. On the other hand, introns have been clearly demonstrated to invade genetic sequences in recent times while sex chromosomes evolved from a pair of autosomes within the last 300 millions years. One main difference between sex chromosomes and autosomes in mammalian is that sex chromosomes recombination stopped. Thus, recombination might be the main determinant for eukaryotes gaining spliceosomal introns. To further prove that and avoid giving weak signal, the whole genomes from eight eukaryotic species are analyzed and present strong signal for above the trend (3) in three species (t-test, P = 0.55 for C. elegans, P = 0.72 for D. melanogaster and P = 0.83 for A. thaliana). These results suggest that the genome-wide coincidence as above (3) can only be caused by the large-scale random unequal crossover in eukaryote meiosis, which might have fueled spliceosomal introns but hardly occurred in prokaryotes.
Collapse
|
29
|
Yang F, Baumann C, De La Fuente R. Persistence of histone H2AX phosphorylation after meiotic chromosome synapsis and abnormal centromere cohesion in poly (ADP-ribose) polymerase (Parp-1) null oocytes. Dev Biol 2009; 331:326-38. [PMID: 19463809 DOI: 10.1016/j.ydbio.2009.05.550] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 01/07/2023]
Abstract
In spite of the impact of aneuploidy on human health little is known concerning the molecular mechanisms involved in the formation of structural or numerical chromosome abnormalities during meiosis. Here, we provide novel evidence indicating that lack of PARP-1 function during oogenesis predisposes the female gamete to genome instability. During prophase I of meiosis, a high proportion of Parp-1((-/-)) mouse oocytes exhibit a spectrum of meiotic defects including incomplete homologous chromosome synapsis or persistent histone H2AX phosphorylation in fully synapsed chromosomes at the late pachytene stage. Moreover, the X chromosome bivalent is also prone to exhibit persistent double strand DNA breaks (DSBs). In striking contrast, such defects were not detected in mutant pachytene spermatocytes. In fully-grown wild type oocytes at the germinal vesicle stage, PARP-1 protein associates with nuclear speckles and upon meiotic resumption, undergoes a striking re-localization towards spindle poles as well as pericentric heterochromatin domains at the metaphase II stage. Notably, a high proportion of in vivo matured Parp-1((-/-)) oocytes show lack of recruitment of the kinetochore-associated protein BUB3 to centromeric domains and fail to maintain metaphase II arrest. Defects in chromatin modifications in the form of persistent histone H2AX phosphorylation during prophase I of meiosis and deficient sister chromatid cohesion during metaphase II predispose mutant oocytes to premature anaphase II onset upon removal from the oviductal environment. Our results indicate that PARP-1 plays a critical role in the maintenance of chromosome stability at key stages of meiosis in the female germ line. Moreover, in the metaphase II stage oocyte PARP-1 is required for the regulation of centromere structure and function through a mechanism that involves the recruitment of BUB3 protein to centromeric domains.
Collapse
Affiliation(s)
- Feikun Yang
- Department of Clinical Studies, Center for Animal Transgenesis and Germ Cell Research, University of Pennsylvania, New Bolton Center, Kennett Square, 19348, USA
| | | | | |
Collapse
|
30
|
Burgoyne PS, Mahadevaiah SK, Turner JMA. The consequences of asynapsis for mammalian meiosis. Nat Rev Genet 2009; 10:207-16. [PMID: 19188923 DOI: 10.1038/nrg2505] [Citation(s) in RCA: 278] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
During mammalian meiosis, synapsis of paternal and maternal chromosomes and the generation of DNA breaks are needed to allow reshuffling of parental genes. In mammals errors in synapsis are associated with a male-biased meiotic impairment, which has been attributed to a response to persisting DNA double-stranded breaks in the asynapsed chromosome segments. Recently it was discovered that the chromatin of asynapsed chromosome segments is transcriptionally silenced, providing new insights into the connection between asynapsis and meiotic impairment.
Collapse
Affiliation(s)
- Paul S Burgoyne
- Division of Stem Cell Biology and Developmental Genetics, Medical Research Council National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA.
| | | | | |
Collapse
|
31
|
Mahadevaiah SK, Bourc'his D, de Rooij DG, Bestor TH, Turner JMA, Burgoyne PS. Extensive meiotic asynapsis in mice antagonises meiotic silencing of unsynapsed chromatin and consequently disrupts meiotic sex chromosome inactivation. ACTA ACUST UNITED AC 2008; 182:263-76. [PMID: 18663141 PMCID: PMC2483523 DOI: 10.1083/jcb.200710195] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Chromosome synapsis during zygotene is a prerequisite for the timely homologous recombinational repair of meiotic DNA double-strand breaks (DSBs). Unrepaired DSBs are thought to trigger apoptosis during midpachytene of male meiosis if synapsis fails. An early pachytene response to asynapsis is meiotic silencing of unsynapsed chromatin (MSUC), which, in normal males, silences the X and Y chromosomes (meiotic sex chromosome inactivation [MSCI]). In this study, we show that MSUC occurs in Spo11-null mouse spermatocytes with extensive asynapsis but lacking meiotic DSBs. In contrast, three mutants (Dnmt3l, Msh5, and Dmc1) with high levels of asynapsis and numerous persistent unrepaired DSBs have a severely impaired MSUC response. We suggest that MSUC-related proteins, including the MSUC initiator BRCA1, are sequestered at unrepaired DSBs. All four mutants fail to silence the X and Y chromosomes (MSCI failure), which is sufficient to explain the midpachytene apoptosis. Apoptosis does not occur in mice with a single additional asynapsed chromosome with unrepaired meiotic DSBs and no disturbance of MSCI.
Collapse
Affiliation(s)
- Shantha K Mahadevaiah
- Division of Stem Cell Biology and Developmental Genetics, Medical Research Council National Institute for Medical Research, London NW7 1AA, England, UK
| | | | | | | | | | | |
Collapse
|
32
|
Barchi M, Roig I, Di Giacomo M, de Rooij DG, Keeney S, Jasin M. ATM promotes the obligate XY crossover and both crossover control and chromosome axis integrity on autosomes. PLoS Genet 2008; 4:e1000076. [PMID: 18497861 PMCID: PMC2374915 DOI: 10.1371/journal.pgen.1000076] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Accepted: 04/17/2008] [Indexed: 12/23/2022] Open
Abstract
During meiosis in most sexually reproducing organisms, recombination forms crossovers between homologous maternal and paternal chromosomes and thereby promotes proper chromosome segregation at the first meiotic division. The number and distribution of crossovers are tightly controlled, but the factors that contribute to this control are poorly understood in most organisms, including mammals. Here we provide evidence that the ATM kinase or protein is essential for proper crossover formation in mouse spermatocytes. ATM deficiency causes multiple phenotypes in humans and mice, including gonadal atrophy. Mouse Atm−/− spermatocytes undergo apoptosis at mid-prophase of meiosis I, but Atm−/− meiotic phenotypes are partially rescued by Spo11 heterozygosity, such that ATM-deficient spermatocytes progress to meiotic metaphase I. Strikingly, Spo11+/−Atm−/− spermatocytes are defective in forming the obligate crossover on the sex chromosomes, even though the XY pair is usually incorporated in a sex body and is transcriptionally inactivated as in normal spermatocytes. The XY crossover defect correlates with the appearance of lagging chromosomes at metaphase I, which may trigger the extensive metaphase apoptosis that is observed in these cells. In addition, control of the number and distribution of crossovers on autosomes appears to be defective in the absence of ATM because there is an increase in the total number of MLH1 foci, which mark the sites of eventual crossover formation, and because interference between MLH1 foci is perturbed. The axes of autosomes exhibit structural defects that correlate with the positions of ongoing recombination. Together, these findings indicate that ATM plays a role in both crossover control and chromosome axis integrity and further suggests that ATM is important for coordinating these features of meiotic chromosome dynamics. Meiosis is the specialized cell division that gives rise to reproductive cells such as sperm and eggs. During meiosis in most organisms, genetic information is exchanged between homologous maternal and paternal chromosomes through the process of homologous recombination. This recombination forms connections between homologous chromosomes that allow them to segregate accurately when the meiotic cell divides. Recombination defects can result in reproductive cells with abnormal chromosome numbers, which are a major cause of developmental disorders and spontaneous abortions in humans. Meiotic recombination is tightly controlled such that each pair of chromosomes undergoes at least one crossover recombination event despite a low average number of crossovers per chromosome. Moreover, multiple crossovers on the same chromosome tend to be evenly and widely spaced. Mechanisms of this control are not well understood, but here we provide evidence that ATM protein is required for normal operation of this process(es) in male mice. ATM has long been known to be involved in cellular responses to DNA damage. Our studies reveal a new function for this protein and also provide new insight into the mechanisms by which meiotic cells ensure accurate transmission of genetic material from one generation to the next.
Collapse
Affiliation(s)
- Marco Barchi
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Ignasi Roig
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Monica Di Giacomo
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Dirk G. de Rooij
- Department of Endocrinology and Metabolism, Faculty of Science, Utrecht University, The Netherlands
- Center for Reproductive Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
- Weill Graduate School of Medical Sciences of Cornell University, New York, New York, United States of America
- * E-mail: (SK); (MJ)
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
- Weill Graduate School of Medical Sciences of Cornell University, New York, New York, United States of America
- * E-mail: (SK); (MJ)
| |
Collapse
|
33
|
Carballo JA, Johnson AL, Sedgwick SG, Cha RS. Phosphorylation of the axial element protein Hop1 by Mec1/Tel1 ensures meiotic interhomolog recombination. Cell 2008; 132:758-70. [PMID: 18329363 DOI: 10.1016/j.cell.2008.01.035] [Citation(s) in RCA: 225] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 11/21/2007] [Accepted: 01/17/2008] [Indexed: 12/29/2022]
Abstract
An essential feature of meiosis is interhomolog recombination whereby a significant fraction of the programmed meiotic double-strand breaks (DSBs) is repaired using an intact homologous non-sister chromatid rather than a sister. Involvement of Mec1 and Tel1, the budding yeast homologs of the mammalian ATR and ATM kinases, in meiotic interhomlog bias has been implicated, but the mechanism remains elusive. Here, we demonstrate that Mec1 and Tel1 promote meiotic interhomolog recombination by targeting the axial element protein Hop1. Without Mec1/Tel1 phosphorylation of Hop1, meiotic DSBs are rapidly repaired via a Dmc1-independent intersister repair pathway, resulting in diminished interhomolog crossing-over leading to spore lethality. We find that Mec1/Tel1-mediated phosphorylation of Hop1 is required for activation of Mek1, a meiotic paralogue of the DNA-damage effector kinase, Rad53p/CHK2. Thus, Hop1 is a meiosis-specific adaptor protein of the Mec1/Tel1 signaling pathway that ensures interhomolog recombination by preventing Dmc1-independent repair of meiotic DSBs.
Collapse
Affiliation(s)
- Jesús A Carballo
- Division of Stem Cell Biology and Developmental Genetics, MRC National Institute for Medical Research, London NW7 1AA, UK
| | | | | | | |
Collapse
|