1
|
Karafiátová M, Bojdová T, Stejskalová M, Harnádková N, Kumar V, Houben A, Chen J, Doležalová A, Honys D, Bartoš J. Unravelling the unusual: chromosome elimination, nondisjunction and extra pollen mitosis characterize the B chromosome in wild sorghum. THE NEW PHYTOLOGIST 2024. [PMID: 39010685 DOI: 10.1111/nph.19954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 06/17/2024] [Indexed: 07/17/2024]
Abstract
The B chromosomes exhibit diverse behaviour compared with conventional genetic models. The capacity of the B chromosome either to accumulate or to be eliminated in a tissue-specific manner is dependent on biological processes related to aberrant cell division(s), but here yet remains compatible with normal development. We studied B chromosome elimination in Sorghum purpureosericeum embryos through cryo-sections and demonstrated the B chromosome instability during plant growth using flow cytometry, molecular markers and fluorescent in situ hybridization techniques. Consequently, using B chromosome-specific probes we revealed the non-Mendelian inheritance of B chromosomes in developing pollen. We disclosed that the occurrence of the B chromosome is specific to certain tissues or organs. The distribution pattern is mainly caused by an extensive elimination that functions primarily during embryo development and persists throughout plant development. Furthermore, we described that B chromosome accumulation can occur either by nondisjunction at first pollen mitosis (PMI) or the initiation of extra nuclear division(s) during pollen development. Our study demonstrates the existence of a not-yet-fully described B chromosome drive process, which is likely under the control of the B chromosome.
Collapse
Affiliation(s)
- Miroslava Karafiátová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 779 00, Olomouc, Czech Republic
| | - Tereza Bojdová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 779 00, Olomouc, Czech Republic
- Department of Cell Biology and Genetics, Faculty of Science, Palacky University, Šlechtitelů 27, 779 00, Olomouc, Czech Republic
| | - Magdaléna Stejskalová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 779 00, Olomouc, Czech Republic
| | - Natália Harnádková
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 779 00, Olomouc, Czech Republic
| | - Vinod Kumar
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 02, Prague 6 - Lysolaje, Czech Republic
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Seeland OT Gatersleben, Germany
| | - Jianyong Chen
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Seeland OT Gatersleben, Germany
| | - Alžběta Doležalová
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 779 00, Olomouc, Czech Republic
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 02, Prague 6 - Lysolaje, Czech Republic
| | - Jan Bartoš
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, 779 00, Olomouc, Czech Republic
| |
Collapse
|
2
|
Estrem B, Davis RE, Wang J. End resection and telomere healing of DNA double-strand breaks during nematode programmed DNA elimination. Nucleic Acids Res 2024:gkae579. [PMID: 38953168 DOI: 10.1093/nar/gkae579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/24/2024] [Accepted: 06/24/2024] [Indexed: 07/03/2024] Open
Abstract
Most DNA double-strand breaks (DSBs) are harmful to genome integrity. However, some forms of DSBs are essential to biological processes, such as meiotic recombination and V(D)J recombination. DSBs are also required for programmed DNA elimination (PDE) in ciliates and nematodes. In nematodes, the DSBs are healed with telomere addition. While telomere addition sites have been well characterized, little is known regarding the DSBs that fragment nematode chromosomes. Here, we used embryos from the human and pig parasitic nematode Ascaris to characterize the DSBs. Using END-seq, we demonstrate that DSBs are introduced before mitosis, followed by extensive end resection. The resection profile is unique for each break site, and the resection generates 3'-overhangs before the addition of neotelomeres. Interestingly, telomere healing occurs much more frequently on retained DSB ends than on eliminated ends. This biased repair of the DSB ends may be due to the sequestration of the eliminated DNA into micronuclei, preventing neotelomere formation at their ends. Additional DNA breaks occur within the eliminated DNA in both Ascaris and Parascaris, ensuring chromosomal breakage and providing a fail-safe mechanism for PDE. Overall, our data indicate that telomere healing of DSBs is specific to the break sites responsible for nematode PDE.
Collapse
Affiliation(s)
- Brandon Estrem
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Richard E Davis
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jianbin Wang
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA
| |
Collapse
|
3
|
Kalfusová R, Herklotz V, Kumke K, Houben A, Kovařík A, Ritz CM, Lunerová J. Epigenetic histone H3 phosphorylation marks discriminate between univalent- and bivalent-forming chromosomes during canina asymmetrical meiosis. ANNALS OF BOTANY 2024; 133:435-446. [PMID: 38127060 PMCID: PMC11006542 DOI: 10.1093/aob/mcad198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND AND AIMS Dogroses (Rosa sect. Caninae) are mostly pentaploid, bearing 2n = 5x = 35 chromosomes in somatic cells. They evolved a unique form of asymmetrical meiosis characterized by two types of chromosomes: (1) chromosomes forming bivalents and distributed in the normal sexual way; and (2) chromosomes occurring as univalents and transferred by a female gamete only. In the mature pollen of pentaploid species, seven bivalent-derived chromosomes are transmitted to offspring, and 21 unpaired univalent chromosomes are eliminated during microsporogenesis. To discriminate between bivalent- and univalent-forming chromosomes, we studied histone H3 phosphorylation patterns regulating meiotic chromosome condensation and segregation. METHODS We analysed histone modification patterns during male canina meiosis in two representative dogrose species, 5x Rosa canina and 5x Rosa rubiginosa, by immunohistochemical and molecular cytogenetics approaches. Immunostaining of meiotic cells included α-tubulin, histone H3 phosphorylation (H3S10p, H3S28p and H3T3p) and methylation (H3K4me3 and H3K27me3) marks. In addition, fluorescent in situ hybridization was carried out with an 18S rDNA probe. KEY RESULTS In the first meiotic division, univalent chromosomes underwent equational division into chromatids, while homologues in bivalents were segregated as regular dyads. In diakinesis, bivalent chromosomes displayed strong H3 phosphorylation signals in proximal regions, spreading to the rest of the chromosome. In contrast, in univalents, the H3 phosphorylation signals were weaker, occurring mostly outside proximal regions largely overlapping with the H3K4me3 signals. Reduced phosphorylation was associated with relative under-condensation of the univalent chromosomes, particularly at early diakinesis. CONCLUSIONS We hypothesize that the absence of pairing and/or recombination in univalent chromosomes negatively affects the histone H3 phosphorylation of their chromatin and perhaps the loading of meiotic-specific cohesins. This apparently destabilizes cohesion of sister chromatids, leading to their premature split in the first meiotic division.
Collapse
Affiliation(s)
- Radka Kalfusová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 00 Brno, Czech Republic
| | - Veit Herklotz
- Senckenberg Museum of Natural History, Senckenberg – Member of the Leibniz Association, Am Museum 1, 02826 Görlitz, Germany
| | - Katrin Kumke
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466 Stadt Seeland, Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466 Stadt Seeland, Germany
| | - Aleš Kovařík
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 00 Brno, Czech Republic
| | - Christiane M Ritz
- Senckenberg Museum of Natural History, Senckenberg – Member of the Leibniz Association, Am Museum 1, 02826 Görlitz, Germany
- Chair of Biodiversity of Higher Plants, Technical University Dresden, D-01069, Dresden, Germany
| | - Jana Lunerová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 00 Brno, Czech Republic
| |
Collapse
|
4
|
Wei H, Zhong Z, Li Z, Zhang Y, Stukenbrock EH, Tang B, Yang N, Baroncelli R, Peng L, Liu Z, He X, Yang Y, Yuan Z. Loss of the accessory chromosome converts a pathogenic tree-root fungus into a mutualistic endophyte. PLANT COMMUNICATIONS 2024; 5:100672. [PMID: 37563834 PMCID: PMC10811371 DOI: 10.1016/j.xplc.2023.100672] [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: 02/17/2023] [Revised: 06/01/2023] [Accepted: 08/04/2023] [Indexed: 08/12/2023]
Abstract
Some fungal accessory chromosomes (ACs) may contribute to virulence in plants. However, the mechanisms by which ACs determine specific traits associated with lifestyle transitions along a symbiotic continuum are not clear. Here we delineated the genetic divergence in two sympatric but considerably variable isolates (16B and 16W) of the poplar-associated fungus Stagonosporopsis rhizophilae. We identified a ∼0.6-Mb horizontally acquired AC in 16W that resulted in a mildly parasitic lifestyle in plants. Complete deletion of the AC (Δ16W) significantly altered the fungal phenotype. Specifically, Δ16W was morphologically more similar to 16B, showed enhanced melanization, and established beneficial interactions with poplar plants, thereby acting as a dark septate endophyte. RNA sequencing (RNA-seq) analysis showed that AC loss induced the upregulation of genes related to root colonization and biosynthesis of indole acetic acid and melanin. We observed that the AC maintained a more open status of chromatin across the genome, indicating an impressive remodeling of cis-regulatory elements upon AC loss, which potentially enhanced symbiotic effectiveness. We demonstrated that the symbiotic capacities were non-host-specific through comparable experiments on Triticum- and Arabidopsis-fungus associations. Furthermore, the three isolates generated symbiotic interactions with a nonvascular liverwort. In summary, our study suggests that the AC is a suppressor of symbiosis and provides insights into the underlying mechanisms of mutualism with vascular plants in the absence of traits encoded by the AC. We speculate that AC-situated effectors and other potential secreted molecules may have evolved to specifically target vascular plants and promote mild virulence.
Collapse
Affiliation(s)
- Huanshen Wei
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Zhenhui Zhong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhongfeng Li
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Yuwei Zhang
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Eva H Stukenbrock
- Environmental Genomics, Christian-Albrechts University, 24118 Kiel, Germany; Max Planck Fellow Group Environmental Genomics, Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.
| | - Boping Tang
- Jiangsu Key Laboratory for Bioresources of Saline Soils, School of Wetlands, Yancheng Teachers University, Yancheng 224002, China
| | - Ningning Yang
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Riccardo Baroncelli
- Department of Agricultural and Food Sciences (DISTAL), University of Bologna, 40127 Bologna, Italy
| | - Long Peng
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Zhuo Liu
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Xinghua He
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Yuzhan Yang
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Zhilin Yuan
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China.
| |
Collapse
|
5
|
Puchta H, Houben A. Plant chromosome engineering - past, present and future. THE NEW PHYTOLOGIST 2024; 241:541-552. [PMID: 37984056 DOI: 10.1111/nph.19414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/24/2023] [Indexed: 11/22/2023]
Abstract
Spontaneous chromosomal rearrangements (CRs) play an essential role in speciation, genome evolution and crop domestication. To be able to use the potential of CRs for breeding, plant chromosome engineering was initiated by fragmenting chromosomes by X-ray irradiation. With the rise of the CRISPR/Cas system, it became possible to induce double-strand breaks (DSBs) in a highly efficient manner at will at any chromosomal position. This has enabled a completely new level of predesigned chromosome engineering. The genetic linkage between specific genes can be broken by inducing chromosomal translocations. Natural inversions, which suppress genetic exchange, can be reverted for breeding. In addition, various approaches for constructing minichromosomes by downsizing regular standard A or supernumerary B chromosomes, which could serve as future vectors in plant biotechnology, have been developed. Recently, a functional synthetic centromere could be constructed. Also, different ways of genome haploidization have been set up, some based on centromere manipulations. In the future, we expect to see even more complex rearrangements, which can be combined with previously developed engineering technologies such as recombinases. Chromosome engineering might help to redefine genetic linkage groups, change the number of chromosomes, stack beneficial genes on mini cargo chromosomes, or set up genetic isolation to avoid outcrossing.
Collapse
Affiliation(s)
- Holger Puchta
- Joseph Gottlieb Kölreuter Institute for Plant Sciences (JKIP) - Molecular Biology, Karlsruhe Institute of Technology (KIT), 76131, Karlsruhe, Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany
| |
Collapse
|
6
|
Borodin PM. Germline-restricted chromosomes of the songbirds. Vavilovskii Zhurnal Genet Selektsii 2023; 27:641-650. [PMID: 38023808 PMCID: PMC10643108 DOI: 10.18699/vjgb-23-75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/30/2023] [Accepted: 06/30/2023] [Indexed: 12/01/2023] Open
Abstract
Germline-restricted chromosomes (GRCs) are present in the genomes of germline cells and absent from somatic cells. A GRC is found in all species of the songbirds (Passeri) and in none of the other bird orders studied to date. This indicates that GRC originated in the common ancestor of the songbirds. The germline-restricted chromosome is permanently absent from somatic cells of the songbird, while female germline cells usually contain two copies of GRC and male ones have one copy. In females, GRCs undergo synapsis and restricted recombination in their terminal regions during meiotic prophase. In males, it is almost always eliminated from spermatocytes. Thus, GRC is inherited almost exclusively through the maternal lineage. The germline-restricted chromosome is a necessary genomic element in the germline cells of songbirds. To date, the GRC genetic composition has been studied in four species only. Some GRC genes are actively expressed in female and male gonads, controlling the development of germline cells and synthesis of the proteins involved in the organization of meiotic chromosomes. Songbird species vary in GRC size and genetic composition. The GRC of each bird species consists of amplified and modified copies of genes from the basic genome of that species. The level of homology between GRCs of different species is relatively low, indicating a high rate of genetic evolution of this chromosome. Transmission through the maternal lineage and suppression of the recombination contribute significantly to the accelerated evolution of GRCs. One may suggest that the rapid coordinated evolution between the GRC genes and the genes of the basic genome in the songbirds might be responsible for the explosive speciation and adaptive radiation of this most species-rich and diverse infraorder of birds.
Collapse
Affiliation(s)
- P M Borodin
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| |
Collapse
|
7
|
Finseth F. Female meiotic drive in plants: mechanisms and dynamics. Curr Opin Genet Dev 2023; 82:102101. [PMID: 37633231 DOI: 10.1016/j.gde.2023.102101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/10/2023] [Accepted: 07/22/2023] [Indexed: 08/28/2023]
Abstract
Female meiosis is fundamentally asymmetric, creating an arena for genetic elements to compete for inclusion in the egg to maximize their transmission. Centromeres, as mediators of chromosomal segregation, are prime candidates to evolve via 'female meiotic drive'. According to the centromere-drive model, the asymmetry of female meiosis ignites a coevolutionary arms race between selfish centromeres and kinetochore proteins, the by-product of which is accelerated sequence divergence. Here, I describe and compare plant models that have been instrumental in uncovering the mechanistic basis of female meiotic drive (maize) and the dynamics of active selfish centromeres in nature (monkeyflowers). Then, I speculate on the mechanistic basis of drive in monkeyflowers, discuss how centromere strength influences chromosomal segregation in plants, and describe new insights into the evolution of plant centromeres.
Collapse
Affiliation(s)
- Findley Finseth
- W.M. Keck Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont, CA 91711, USA.
| |
Collapse
|
8
|
Ebrahimzadegan R, Fuchs J, Chen J, Schubert V, Meister A, Houben A, Mirzaghaderi G. Meiotic segregation and post-meiotic drive of the Festuca pratensis B chromosome. Chromosome Res 2023; 31:26. [PMID: 37658970 PMCID: PMC10474989 DOI: 10.1007/s10577-023-09728-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 09/05/2023]
Abstract
In many species, the transmission of B chromosomes (Bs) does not follow the Mendelian laws of equal segregation and independent assortment. This deviation results in transmission rates of Bs higher than 0.5, a process known as "chromosome drive". Here, we studied the behavior of the 103 Mbp-large B chromosome of Festuca pratensis during all meiotic and mitotic stages of microsporogenesis. Mostly, the B chromosome of F. pratensis segregates during meiosis like standard A chromosomes (As). In some cases, the B passes through meiosis in a non-Mendelian segregation leading to their accumulation already in meiosis. However, a true drive of the B happens during the first pollen mitosis, by which the B preferentially migrates to the generative nucleus. During second pollen mitosis, B divides equally between the two sperms. Despite some differences in the frequency of drive between individuals with different numbers of Bs, at least 82% of drive was observed. Flow cytometry-based quantification of B-containing sperm nuclei agrees with the FISH data.
Collapse
Affiliation(s)
- Rahman Ebrahimzadegan
- Department of Plant Production and Genetics, Faculty of Agriculture, University of Kurdistan, Sanandaj, 66177-15175, Iran
| | - Jörg Fuchs
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany
| | - Jianyong Chen
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany
| | - Armin Meister
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany.
| | - Ghader Mirzaghaderi
- Department of Plant Production and Genetics, Faculty of Agriculture, University of Kurdistan, Sanandaj, 66177-15175, Iran.
| |
Collapse
|
9
|
Silva DM, Akera T. Meiotic drive of noncentromeric loci in mammalian meiosis II eggs. Curr Opin Genet Dev 2023; 81:102082. [PMID: 37406428 PMCID: PMC10527070 DOI: 10.1016/j.gde.2023.102082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 06/02/2023] [Accepted: 06/08/2023] [Indexed: 07/07/2023]
Abstract
The germline produces haploid gametes through a specialized cell division called meiosis. In general, homologous chromosomes from each parent segregate randomly to the daughter cells during meiosis, providing parental alleles with an equal chance of transmission. Meiotic drivers are selfish elements who cheat this process to increase their transmission rate. In female meiosis, selfish centromeres and noncentromeric drivers cheat by preferentially segregating to the egg cell. Selfish centromeres cheat in meiosis I (MI), while noncentromeric drivers can cheat in both meiosis I and meiosis II (MII). Here, we highlight recent advances on our understanding of the molecular mechanisms underlying these genetic cheating strategies, especially focusing on mammalian systems, and discuss new models of how noncentromeric selfish drivers can cheat in MII eggs.
Collapse
Affiliation(s)
- Duilio Mza Silva
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Takashi Akera
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
10
|
Rajpal VR, Sharma S, Sehgal D, Sharma P, Wadhwa N, Dhakate P, Chandra A, Thakur RK, Deb S, Rama Rao S, Mir BA, Raina SN. Comprehending the dynamism of B chromosomes in their journey towards becoming unselfish. Front Cell Dev Biol 2023; 10:1072716. [PMID: 36684438 PMCID: PMC9846793 DOI: 10.3389/fcell.2022.1072716] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/13/2022] [Indexed: 01/06/2023] Open
Abstract
Investigated for more than a century now, B chromosomes (Bs) research has come a long way from Bs being considered parasitic or neutral to becoming unselfish and bringing benefits to their hosts. B chromosomes exist as accessory chromosomes along with the standard A chromosomes (As) across eukaryotic taxa. Represented singly or in multiple copies, B chromosomes are largely heterochromatic but also contain euchromatic and organellar segments. Although B chromosomes are derived entities, they follow their species-specific evolutionary pattern. B chromosomes fail to pair with the standard chromosomes during meiosis and vary in their number, size, composition and structure across taxa and ensure their successful transmission through non-mendelian mechanisms like mitotic, pre-meiotic, meiotic or post-meiotic drives, unique non-disjunction, self-pairing or even imparting benefits to the host when they lack drive. B chromosomes have been associated with cellular processes like sex determination, pathogenicity, resistance to pathogens, phenotypic effects, and differential gene expression. With the advancements in B-omics research, novel insights have been gleaned on their functions, some of which have been associated with the regulation of gene expression of A chromosomes through increased expression of miRNAs or differential expression of transposable elements located on them. The next-generation sequencing and emerging technologies will further likely unravel the cellular, molecular and functional behaviour of these enigmatic entities. Amidst the extensive fluidity shown by B chromosomes in their structural and functional attributes, we perceive that the existence and survival of B chromosomes in the populations most likely seem to be a trade-off between the drive efficiency and adaptive significance versus their adverse effects on reproduction.
Collapse
Affiliation(s)
- Vijay Rani Rajpal
- Department of Botany, Hansraj College, University of Delhi, Delhi, India,*Correspondence: Vijay Rani Rajpal, , ; Soom Nath Raina,
| | - Suman Sharma
- Department of Botany, Ramjas College, University of Delhi, Delhi, India
| | - Deepmala Sehgal
- Syngenta, International Maize and Wheat Improvement Center (CIMMYT), Texcoco, Mexico
| | - Prashansa Sharma
- Department of Botany, Hansraj College, University of Delhi, Delhi, India
| | - Nikita Wadhwa
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | | | - Atika Chandra
- Department of Botany, Maitreyi College, University of Delhi, New Delhi, India
| | - Rakesh Kr. Thakur
- Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India
| | - Sohini Deb
- Department of Biotechnology and Bioinformatics, North Eastern Hill University, Shillong, Meghalaya, India
| | - Satyawada Rama Rao
- Department of Biotechnology and Bioinformatics, North Eastern Hill University, Shillong, Meghalaya, India
| | - Bilal Ahmad Mir
- Department of Botany, University of Kashmir, Srinagar, India
| | - Soom Nath Raina
- Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India,*Correspondence: Vijay Rani Rajpal, , ; Soom Nath Raina,
| |
Collapse
|
11
|
Peng H, Mirouze M, Bucher E. Extrachromosomal circular DNA: A neglected nucleic acid molecule in plants. CURRENT OPINION IN PLANT BIOLOGY 2022; 69:102263. [PMID: 35872391 DOI: 10.1016/j.pbi.2022.102263] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/15/2022] [Accepted: 06/19/2022] [Indexed: 06/15/2023]
Abstract
Throughout the years, most plant genomic studies were focused on nuclear chromosomes. Extrachromosomal circular DNA (eccDNA) has largely been neglected for decades since its discovery in 1965. While initial research showed that eccDNAs can originate from highly repetitive sequences, recent findings show that many regions of the genome can contribute to the eccDNA pool. Currently, the biological functions of eccDNAs, if any, are a mystery but recent studies have indicated that they can be regulated by different genomic loci and contribute to stress response and adaptation. In this review, we outline current relevant technological developments facilitating eccDNA identification and the latest discoveries about eccDNAs in plants. Finally, we explore the probable functions and future research directions that could be undertaken with respect to different eccDNA sources.
Collapse
Affiliation(s)
- Haoran Peng
- Crop Genome Dynamics Group, Agroscope Changins, 1260, Nyon, Switzerland; Department of Botany and Plant Biology, Section of Biology, Faculty of Science, University of Geneva, 1211, Geneva, Switzerland
| | - Marie Mirouze
- Institut de Recherche pour le Développement (IRD), EMR269 MANGO, Université de Perpignan, 66860 Perpignan, France; Laboratory of Plant Genome and Development, Université de Perpignan, 66860, Perpignan, France.
| | - Etienne Bucher
- Crop Genome Dynamics Group, Agroscope Changins, 1260, Nyon, Switzerland.
| |
Collapse
|