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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: 0.5] [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.
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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,
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Dhar MK, Kour J, Kaul S. Origin, Behaviour, and Transmission of B Chromosome with Special Reference to Plantago lagopus. Genes (Basel) 2019; 10:E152. [PMID: 30781667 PMCID: PMC6410184 DOI: 10.3390/genes10020152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 11/30/2022] Open
Abstract
B chromosomes have been reported in many eukaryotic organisms. These chromosomes occur in addition to the standard complement of a species. Bs do not pair with any of the A chromosomes and they have generally been considered to be non-essential and genetically inert. However, due to tremendous advancements in the technologies, the molecular composition of B chromosomes has been determined. The sequencing data has revealed that B chromosomes have originated from A chromosomes and they are rich in repetitive elements. In our laboratory, a novel B chromosome was discovered in Plantago lagopus. Using molecular cytogenetic techniques, the B chromosome was found to be composed of ribosomal DNA sequences. However, further characterization of the chromosome using next generation sequencing (NGS) etc. revealed that the B chromosome is a mosaic of sequences derived from A chromosomes, 5S ribosomal DNA (rDNA), 45S rDNA, and various types of repetitive elements. The transmission of B chromosome through the female sex track did not follow the Mendelian principles. The chromosome was found to have drive due to which it was perpetuating in populations. The present paper attempts to summarize the information on nature, transmission, and origin of B chromosomes, particularly the current status of our knowledge in P. lagopus.
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Affiliation(s)
- Manoj K Dhar
- Genome Research Laboratory, School of Biotechnology, University of Jammu, Jammu-180006, India.
| | - Jasmeet Kour
- Genome Research Laboratory, School of Biotechnology, University of Jammu, Jammu-180006, India.
| | - Sanjana Kaul
- Genome Research Laboratory, School of Biotechnology, University of Jammu, Jammu-180006, India.
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Singh V, Gupta RC, Sharma K, Sharma V, Sharma M, Kaur K. Male Meiotic Studies in 29 Species of Lamiaceae from Sirmaur District of Himachal Pradesh, India. CYTOLOGIA 2018. [DOI: 10.1508/cytologia.83.235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
| | | | - Kusum Sharma
- Department of Botany, Shoolini Institute of Life Sciences and Business Management
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Rey MD, Martín AC, Smedley M, Hayta S, Harwood W, Shaw P, Moore G. Magnesium Increases Homoeologous Crossover Frequency During Meiosis in ZIP4 ( Ph1 Gene) Mutant Wheat-Wild Relative Hybrids. FRONTIERS IN PLANT SCIENCE 2018; 9:509. [PMID: 29731763 PMCID: PMC5920029 DOI: 10.3389/fpls.2018.00509] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/03/2018] [Indexed: 05/18/2023]
Abstract
Wild relatives provide an important source of useful traits in wheat breeding. Wheat and wild relative hybrids have been widely used in breeding programs to introduce such traits into wheat. However, successful introgression is limited by the low frequency of homoeologous crossover (CO) between wheat and wild relative chromosomes. Hybrids between wheat carrying a 70 Mb deletion on chromosome 5B (ph1b) and wild relatives, have been exploited to increase the level of homoeologous CO, allowing chromosome exchange between their chromosomes. In ph1b-rye hybrids, CO number increases from a mean of 1 CO to 7 COs per cell. CO number can be further increased up to a mean of 12 COs per cell in these ph1b hybrids by treating the plants with Hoagland solution. More recently, it was shown that the major meiotic crossover gene ZIP4 on chromosome 5B (TaZIP4-B2) within the 70 Mb deletion, was responsible for the restriction of homoeologous COs in wheat-wild relative hybrids, confirming the ph1b phenotype as a complete Tazip4-B2 deletion mutant (Tazip4-B2 ph1b). In this study, we have identified the particular Hoagland solution constituent responsible for the increased chiasma frequency in Tazip4-B2 ph1b mutant-rye hybrids and extended the analysis to Tazip4-B2 TILLING and CRISPR mutant-Ae variabilis hybrids. Chiasma frequency at meiotic metaphase I, in the absence of each Hoagland solution macronutrient (NH4 H2PO4, KNO3, Ca (NO3)2·4H2O or Mg SO4·7H2O) was analyzed. A significant decrease in homoeologous CO frequency was observed when the Mg2+ ion was absent. A significant increase of homoeologous CO frequency was observed in all analyzed hybrids, when plants were irrigated with a 1 mM Mg2+ solution. These observations suggest a role for magnesium supplementation in improving the success of genetic material introgression from wild relatives into wheat.
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Affiliation(s)
- María-Dolores Rey
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Azahara C. Martín
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Mark Smedley
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Sadiye Hayta
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Wendy Harwood
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Peter Shaw
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Graham Moore
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
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Rey MD, Martín AC, Smedley M, Hayta S, Harwood W, Shaw P, Moore G. Magnesium Increases Homoeologous Crossover Frequency During Meiosis in ZIP4 ( Ph1 Gene) Mutant Wheat-Wild Relative Hybrids. FRONTIERS IN PLANT SCIENCE 2018; 9:509. [PMID: 29731763 DOI: 10.1101/278341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/03/2018] [Indexed: 05/28/2023]
Abstract
Wild relatives provide an important source of useful traits in wheat breeding. Wheat and wild relative hybrids have been widely used in breeding programs to introduce such traits into wheat. However, successful introgression is limited by the low frequency of homoeologous crossover (CO) between wheat and wild relative chromosomes. Hybrids between wheat carrying a 70 Mb deletion on chromosome 5B (ph1b) and wild relatives, have been exploited to increase the level of homoeologous CO, allowing chromosome exchange between their chromosomes. In ph1b-rye hybrids, CO number increases from a mean of 1 CO to 7 COs per cell. CO number can be further increased up to a mean of 12 COs per cell in these ph1b hybrids by treating the plants with Hoagland solution. More recently, it was shown that the major meiotic crossover gene ZIP4 on chromosome 5B (TaZIP4-B2) within the 70 Mb deletion, was responsible for the restriction of homoeologous COs in wheat-wild relative hybrids, confirming the ph1b phenotype as a complete Tazip4-B2 deletion mutant (Tazip4-B2 ph1b). In this study, we have identified the particular Hoagland solution constituent responsible for the increased chiasma frequency in Tazip4-B2 ph1b mutant-rye hybrids and extended the analysis to Tazip4-B2 TILLING and CRISPR mutant-Ae variabilis hybrids. Chiasma frequency at meiotic metaphase I, in the absence of each Hoagland solution macronutrient (NH4 H2PO4, KNO3, Ca (NO3)2·4H2O or Mg SO4·7H2O) was analyzed. A significant decrease in homoeologous CO frequency was observed when the Mg2+ ion was absent. A significant increase of homoeologous CO frequency was observed in all analyzed hybrids, when plants were irrigated with a 1 mM Mg2+ solution. These observations suggest a role for magnesium supplementation in improving the success of genetic material introgression from wild relatives into wheat.
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Affiliation(s)
- María-Dolores Rey
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Azahara C Martín
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Mark Smedley
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Sadiye Hayta
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Wendy Harwood
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Peter Shaw
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Graham Moore
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
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Harper J, Phillips D, Thomas A, Gasior D, Evans C, Powell W, King J, King I, Jenkins G, Armstead I. B chromosomes are associated with redistribution of genetic recombination towards lower recombination chromosomal regions in perennial ryegrass. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1861-1871. [PMID: 29635481 PMCID: PMC6019035 DOI: 10.1093/jxb/ery052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/10/2018] [Indexed: 05/26/2023]
Abstract
Supernumerary 'B' chromosomes are non-essential components of the genome present in a range of plant and animal species-including many grasses. Within diploid and polyploid ryegrass and fescue species, including the forage grass perennial ryegrass (Lolium perenne L.), the presence of B chromosomes has been reported as influencing both chromosome pairing and chiasma frequencies. In this study, the effects of the presence/absence of B chromosomes on genetic recombination has been investigated through generating DArT (Diversity Arrays Technology) marker genetic maps for six perennial ryegrass diploid populations, the pollen parents of which contained either two B or zero B chromosomes. Through genetic and cytological analyses of these progeny and their parents, we have identified that, while overall cytological estimates of chiasma frequencies were significantly lower in pollen mother cells with two B chromosomes as compared with zero B chromosomes, the recombination frequencies within some marker intervals were actually increased, particularly for marker intervals in lower recombination regions of chromosomes, namely pericentromeric regions. Thus, in perennial ryegrass, the presence of two B chromosomes redistributed patterns of meiotic recombination in pollen mother cells in ways which could increase the range of allelic variation available to plant breeders.
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Affiliation(s)
- John Harper
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | - Dylan Phillips
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | - Ann Thomas
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | - Dagmara Gasior
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | - Caron Evans
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | | | - Julie King
- School of Biosciences, University of Nottingham, Sutton Bonington, UK
| | - Ian King
- School of Biosciences, University of Nottingham, Sutton Bonington, UK
| | - Glyn Jenkins
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
| | - Ian Armstead
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK
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7
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Lambing C, Heckmann S. Tackling Plant Meiosis: From Model Research to Crop Improvement. FRONTIERS IN PLANT SCIENCE 2018; 9:829. [PMID: 29971082 PMCID: PMC6018109 DOI: 10.3389/fpls.2018.00829] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/28/2018] [Indexed: 05/04/2023]
Abstract
Genetic engineering and traditional plant breeding, which harnesses the natural genetic variation that arises during meiosis, will have key roles to improve crop varieties and thus deliver Food Security in the future. Meiosis, a specialized cell division producing haploid gametes to maintain somatic diploidy following their fusion, assures genetic variation by regulated genetic exchange through homologous recombination. However, meiotic recombination events are restricted in their total number and their distribution along chromosomes limiting allelic variations in breeding programs. Thus, modifying the number and distribution of meiotic recombination events has great potential to improve and accelerate plant breeding. In recent years much progress has been made in understanding meiotic progression and recombination in plants. Many genes and factors involved in these processes have been identified primarily in Arabidopsis thaliana but also more recently in crops such as Brassica, rice, barley, maize, or wheat. These advances put researchers in the position to translate acquired knowledge to various crops likely improving and accelerating breeding programs. However, although fundamental aspects of meiotic progression and recombination are conserved between species, differences in genome size and organization (due to repetitive DNA content and ploidy level) exist, particularly among plants, that likely account for differences in meiotic progression and recombination patterns found between species. Thus, tools and approaches are needed to better understand differences and similarities in meiotic progression and recombination among plants, to study fundamental aspects of meiosis in a variety of plants including crops and non-model species, and to transfer knowledge into crop species. In this article, we provide an overview of tools and approaches available to study plant meiosis, highlight new techniques, give examples of areas of future research and review distinct aspects of meiosis in non-model species.
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Affiliation(s)
- Christophe Lambing
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Christophe Lambing, Stefan Heckmann,
| | - Stefan Heckmann
- Independent Research Group Meiosis, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany
- *Correspondence: Christophe Lambing, Stefan Heckmann,
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8
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Rey MD, Martín AC, Higgins J, Swarbreck D, Uauy C, Shaw P, Moore G. Exploiting the ZIP4 homologue within the wheat Ph1 locus has identified two lines exhibiting homoeologous crossover in wheat-wild relative hybrids. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2017; 37:95. [PMID: 28781573 PMCID: PMC5515957 DOI: 10.1007/s11032-017-0700-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/03/2017] [Indexed: 05/20/2023]
Abstract
Despite possessing related ancestral genomes, hexaploid wheat behaves as a diploid during meiosis. The wheat Ph1 locus promotes accurate synapsis and crossover of homologous chromosomes. Interspecific hybrids between wheat and wild relatives are exploited by breeders to introgress important traits from wild relatives into wheat, although in hybrids between hexaploid wheat and wild relatives, which possess only homoeologues, crossovers do not take place during meiosis at metaphase I. However, in hybrids between Ph1 deletion mutants and wild relatives, crossovers do take place. A single Ph1 deletion (ph1b) mutant has been exploited for the last 40 years for this activity. We show here that chemically induced mutant lines, selected for a mutation in TaZIP4-B2 within the Ph1 locus, exhibit high levels of homoeologous crossovers when crossed with wild relatives. Tazip4-B2 mutant lines may be more stable over multiple generations, as multivalents causing accumulation of chromosome translocations are less frequent. Exploitation of such Tazip4-B2 mutants, rather than mutants with whole Ph1 locus deletions, may therefore improve introgression of wild relative chromosome segments into wheat.
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Affiliation(s)
| | | | - Janet Higgins
- Earlham Institute, Norwich Research Park, Norwich, NR4 7UZ UK
| | - David Swarbreck
- Earlham Institute, Norwich Research Park, Norwich, NR4 7UZ UK
| | - Cristobal Uauy
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
| | - Peter Shaw
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
| | - Graham Moore
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
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Serrano ÉA, Araya-Jaime C, Suárez-Villota EY, Oliveira C, Foresti F. Meiotic behavior and H3K4m distribution in B chromosomes of Characidium gomesi (Characiformes, Crenuchidae). COMPARATIVE CYTOGENETICS 2016; 10:255-268. [PMID: 27551347 PMCID: PMC4977801 DOI: 10.3897/compcytogen.v10i2.7939] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/21/2016] [Indexed: 06/06/2023]
Abstract
Characidium gomesi Travasso, 1956 specimens from the Pardo River have up to four heterochromatic supernumerary chromosomes, derived from the sex chromosomes. To access the meiotic behavior and distribution of an active chromatin marker, males and females of Characidium gomesi with two or three B chromosomes were analyzed. Mitotic chromosomes were characterized using C-banding and FISH with B chromosome probes. Meiocytes were subjected to immunofluorescence-FISH assay using anti-SYCP3, anti-H3K4m, and B chromosomes probes. Molecular homology of supernumeraries was confirmed by FISH and by its bivalent conformation in individuals with two of these chromosomes. In individuals with three Bs, these elements formed a bivalent and a univalent. Supernumerary and sex chromosomes exhibited H3K4m signals during pachytene contrasting with their heterochromatic and asynaptic nature, which suggest a more structural role than functional of this histone modification. The implications of this result are discussed in light of the homology, meiotic nuclear organization, and meiotic silencing of unsynapsed chomatin.
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Affiliation(s)
- Érica Alves Serrano
- Departamento de Morfologia, Instituto de Biociências, Universidade Estadual Paulista, Distrito de Rubião Junior, s/n, 18618-970, Botucatu, São Paulo, Brazil
| | - Cristian Araya-Jaime
- Departamento de Morfologia, Instituto de Biociências, Universidade Estadual Paulista, Distrito de Rubião Junior, s/n, 18618-970, Botucatu, São Paulo, Brazil
| | - Elkin Y. Suárez-Villota
- Instituto de Ciencias Marinas y Limnólogicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
- Laboratório de Ecologia e Evolução, Instituto Butantan, Avenida Vital Brazil, 1500, CEP 05503-900, São Paulo, São Paulo, Brazil
| | - Claudio Oliveira
- Departamento de Morfologia, Instituto de Biociências, Universidade Estadual Paulista, Distrito de Rubião Junior, s/n, 18618-970, Botucatu, São Paulo, Brazil
| | - Fausto Foresti
- Departamento de Morfologia, Instituto de Biociências, Universidade Estadual Paulista, Distrito de Rubião Junior, s/n, 18618-970, Botucatu, São Paulo, Brazil
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Houben A, Banaei-Moghaddam AM, Klemme S, Timmis JN. Evolution and biology of supernumerary B chromosomes. Cell Mol Life Sci 2014; 71:467-78. [PMID: 23912901 PMCID: PMC11113615 DOI: 10.1007/s00018-013-1437-7] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 07/02/2013] [Accepted: 07/24/2013] [Indexed: 12/23/2022]
Abstract
B chromosomes (Bs) are dispensable components of the genome exhibiting non-Mendelian inheritance and have been widely reported on over several thousand eukaryotes, but still remain an evolutionary mystery ever since their first discovery over a century ago [1]. Recent advances in genome analysis have significantly improved our knowledge on the origin and composition of Bs in the last few years. In contrast to the prevalent view that Bs do not harbor genes, recent analysis revealed that Bs of sequenced species are rich in gene-derived sequences. We summarize the latest findings on supernumerary chromosomes with a special focus on the origin, DNA composition, and the non-Mendelian accumulation mechanism of Bs.
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Affiliation(s)
- Andreas Houben
- Chromosome Structure and Function Laboratory, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466, Gatersleben, Germany,
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