1
|
Homologous chromosome associations in domains before meiosis could facilitate chromosome recognition and pairing in wheat. Sci Rep 2022; 12:10597. [PMID: 35732879 PMCID: PMC9217977 DOI: 10.1038/s41598-022-14843-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/13/2022] [Indexed: 12/05/2022] Open
Abstract
The increasing human population demands an increase in crop yields that must be implemented through breeding programmes to ensure a more efficient and sustainable production of agro-food products. In the framework of breeding, genetic crosses are developed between cultivated species such as wheat and their relative species that are used as genetic donors to transfer desirable agronomic traits into the crop. Unfortunately, interspecific associations between chromosomes from the donor species and the cultivar are rare during meiosis, the process to produce gametes in organisms with sexual reproduction, hampering the transfer of genetic variability into wheat. In addition, little is known about how homologous (equivalent) chromosomes initiate interaction and recognition within the cell nucleus to enter meiosis. In this context, we aim to get insight into wheat chromatin structure, particularly the distribution of homologous chromosomes within the cell nucleus and their putative interactions in premeiotic stages to facilitate chromosome associations and recombination at the beginning of meiosis. Cytogenetics allows the study of both the structure and the behaviour of chromosomes during meiosis and is key in plant breeding. In this study we visualized an extra pair of barley homologous chromosomes in a wheat genetic background to study the spatial distribution, arrangements and interactions occurring exclusively between this pair of homologous chromosomes during premeiosis using fluorescence in situ hybridization (FISH). Our results suggest that homologous chromosomes can initiate interactions in premeiotic stages that could facilitate the processes of specific chromosome recognition and association occurring at the onset of meiosis.
Collapse
|
2
|
Abstract
Meiosis is the basis of the generative reproduction of eukaryotes. The crucial first step is homologous chromosome pairing. In higher eukaryotes, micrometer-scale chromosomes, micrometer distances apart, are brought together by nanometer DNA sequences, at least a factor of 1000 size difference. Models of homology search, homologue movement, and pairing at the DNA level in higher eukaryotes are primarily based on studies with yeast where the emphasis is on the induction and repair of DNA double-strand breaks (DSB). For such a model, the very large nuclei of most plants and animals present serious problems. Homology search without DSBs cannot be explained by models based on DSB repair. The movement of homologues to meet each other and make contact at the molecular level is not understood. These problems are discussed and the conclusion is that at present practically nothing is known of meiotic homologue pairing in higher eukaryotes up to the formation of the synaptonemal complex, and that new, necessarily speculative models must be developed. Arguments are given that RNA plays a central role in homology search and a tentative model involving RNA in homology search is presented. A role of actin in homologue movement is proposed. The primary role of DSBs in higher eukaryotes is concluded to not be in paring but in the preparation of Holliday junctions, ultimately leading to chromatid exchange.
Collapse
Affiliation(s)
- J Sybenga
- Laboratory of Genetics, Wageningen University, Wageningen, the Netherlands.,Laboratory of Genetics, Wageningen University, Wageningen, the Netherlands
| |
Collapse
|
3
|
Svačina R, Sourdille P, Kopecký D, Bartoš J. Chromosome Pairing in Polyploid Grasses. FRONTIERS IN PLANT SCIENCE 2020; 11:1056. [PMID: 32733528 PMCID: PMC7363976 DOI: 10.3389/fpls.2020.01056] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 06/26/2020] [Indexed: 05/20/2023]
Abstract
Polyploids are species in which three or more sets of chromosomes coexist. Polyploidy frequently occurs in plants and plays a major role in their evolution. Based on their origin, polyploid species can be divided into two groups: autopolyploids and allopolyploids. The autopolyploids arise by multiplication of the chromosome sets from a single species, whereas allopolyploids emerge from the hybridization between distinct species followed or preceded by whole genome duplication, leading to the combination of divergent genomes. Having a polyploid constitution offers some fitness advantages, which could become evolutionarily successful. Nevertheless, polyploid species must develop mechanism(s) that control proper segregation of genetic material during meiosis, and hence, genome stability. Otherwise, the coexistence of more than two copies of the same or similar chromosome sets may lead to multivalent formation during the first meiotic division and subsequent production of aneuploid gametes. In this review, we aim to discuss the pathways leading to the formation of polyploids, the occurrence of polyploidy in the grass family (Poaceae), and mechanisms controlling chromosome associations during meiosis, with special emphasis on wheat.
Collapse
Affiliation(s)
- Radim Svačina
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czechia
| | - Pierre Sourdille
- INRA, Génétique, Diversité, Ecophysiologie des Céréales, Clermont-Ferrand, France
| | - David Kopecký
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czechia
| | - Jan Bartoš
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czechia
| |
Collapse
|
4
|
Martín AC, Borrill P, Higgins J, Alabdullah A, Ramírez-González RH, Swarbreck D, Uauy C, Shaw P, Moore G. Genome-Wide Transcription During Early Wheat Meiosis Is Independent of Synapsis, Ploidy Level, and the Ph1 Locus. FRONTIERS IN PLANT SCIENCE 2018; 9:1791. [PMID: 30564262 PMCID: PMC6288783 DOI: 10.3389/fpls.2018.01791] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/19/2018] [Indexed: 05/22/2023]
Abstract
Polyploidization is a fundamental process in plant evolution. One of the biggest challenges faced by a new polyploid is meiosis, particularly discriminating between multiple related chromosomes so that only homologous chromosomes synapse and recombine to ensure regular chromosome segregation and balanced gametes. Despite its large genome size, high DNA repetitive content and similarity between homoeologous chromosomes, hexaploid wheat completes meiosis in a shorter period than diploid species with a much smaller genome. Therefore, during wheat meiosis, mechanisms additional to the classical model based on DNA sequence homology, must facilitate more efficient homologous recognition. One such mechanism could involve exploitation of differences in chromosome structure between homologs and homoeologs at the onset of meiosis. In turn, these chromatin changes, can be expected to be linked to transcriptional gene activity. In this study, we present an extensive analysis of a large RNA-seq data derived from six different genotypes: wheat, wheat-rye hybrids and newly synthesized octoploid triticale, both in the presence and absence of the Ph1 locus. Plant material was collected at early prophase, at the transition leptotene-zygotene, when the telomere bouquet is forming and synapsis between homologs is beginning. The six genotypes exhibit different levels of synapsis and chromatin structure at this stage; therefore, recombination and consequently segregation, are also different. Unexpectedly, our study reveals that neither synapsis, whole genome duplication nor the absence of the Ph1 locus are associated with major changes in gene expression levels during early meiotic prophase. Overall wheat transcription at this meiotic stage is therefore highly resilient to such alterations, even in the presence of major chromatin structural changes. Further studies in wheat and other polyploid species will be required to reveal whether these observations are specific to wheat meiosis.
Collapse
Affiliation(s)
| | - Philippa Borrill
- John Innes Centre, Norwich, United Kingdom
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | | | | | | | | | | | - Peter Shaw
- John Innes Centre, Norwich, United Kingdom
| | | |
Collapse
|
5
|
Poggio L, González GE. Cytological diploidization of paleopolyploid genus Zea: Divergence between homoeologous chromosomes or activity of pairing regulator genes? PLoS One 2018; 13:e0189644. [PMID: 29293518 PMCID: PMC5749740 DOI: 10.1371/journal.pone.0189644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/29/2017] [Indexed: 11/18/2022] Open
Abstract
Cytological diploidization process is different in autopolyploid and allopolyploid species. Colchicine applied at the onset of meiosis suppresses the effect of pairing regulator genes resulting multivalents formation in bivalent-forming species. Colchicine treated maizes (4x = 2n = 20, AmAmBmBm) showed up to 5IV, suggesting pairing between chromosomes from genomes homoeologous Am and Bm. In untreated individuals of the alloautooctoploid Zea perennis (8x = 2n = 40, ApApAp´Ap´Bp1Bp1Bp2Bp2) the most frequent configuration was 5IV+10II (formed by A and B genomes, respectively). The colchicine treated Z. perennis show up to 10IV revealing higher affinity within genomes A and B, but any homology among them. These results suggest the presence of a paring regulator locus (PrZ) in maize and Z. perennis, whose expression is suppressed by colchicine. It could be postulated that in Z. perennis, PrZ would affect independently the genomes A and B, being relevant the threshold of homology, the fidelity of pairing in each genomes and the ploidy level. Cytological analysis of the treated hexaploid hybrids (6x = 2n = 30), with Z. perennis as a parental, strongly suggests that PrZ is less effective in only one doses. This conclusion was reinforced by the homoeologous pairing observed in untreated dihaploid maizes, which showed up to 5II. Meiotic behaviour of individuals treated with different doses of colchicine allowed to postulate that PrZ affect the homoeologous association by controlling entire genomes (Am or Bm) rather than individual chromosomes. Based on cytological and statistical results it is possible to propose that the cytological diploidization in Zea species occurs by restriction of pairing between homoeologous chromosomes or by genetical divergence of the homoeologous chromosomes, as was observed in untreated Z. mays ssp. parviglumis. These are independent but complementary systems and could be acting jointly in the same nucleus.
Collapse
Affiliation(s)
- Lidia Poggio
- Instituto de Ecología, Genética y Evolución (IEGEBA, Consejo Nacional de Investigaciones Científicas y Técnicas—CONICET)—Laboratorio de Citogenética y Evolución (LaCyE), Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Graciela Esther González
- Instituto de Ecología, Genética y Evolución (IEGEBA, Consejo Nacional de Investigaciones Científicas y Técnicas—CONICET)—Laboratorio de Citogenética y Evolución (LaCyE), Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
- * E-mail:
| |
Collapse
|
6
|
Calderón MC, Rey MD, Martín A, Prieto P. Homoeologous Chromosomes From Two Hordeum Species Can Recognize and Associate During Meiosis in Wheat in the Presence of the Ph1 Locus. FRONTIERS IN PLANT SCIENCE 2018; 9:585. [PMID: 29765389 PMCID: PMC5938817 DOI: 10.3389/fpls.2018.00585] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/13/2018] [Indexed: 05/20/2023]
Abstract
Understanding the system of a basic eukaryotic cellular mechanism like meiosis is of fundamental importance in plant biology. Moreover, it is also of great strategic interest in plant breeding since unzipping the mechanism of chromosome specificity/pairing during meiosis will allow its manipulation to introduce genetic variability from related species into a crop. The success of meiosis in a polyploid like wheat strongly depends on regular pairing of homologous (identical) chromosomes and recombination, processes mainly controlled by the Ph1 locus. This means that pairing and recombination of related chromosomes rarely occur in the presence of this locus, making difficult wheat breeding trough the incorporation of genetic variability from related species. In this work, we show that wild and cultivated barley chromosomes associate in the wheat background even in the presence of the Ph1 locus. We have developed double monosomic wheat lines carrying two chromosomes from two barley species for the same and different homoeology chromosome group, respectively. Genetic in situ hybridization revealed that homoeologous Hordeum chromosomes recognize each other and pair during early meiosis in wheat. However, crossing over does not occur at any time and they remained always as univalents during meiosis metaphase I. Our results suggest that the Ph1 locus does not prevent chromosome recognition and pairing but crossing over between homoeologous. The role of subtelomeres in chromosome recognition is also discussed.
Collapse
Affiliation(s)
- María C. Calderón
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
| | | | - Antonio Martín
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
| | - Pilar Prieto
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
- *Correspondence: Pilar Prieto
| |
Collapse
|
7
|
Lawrence EJ, Griffin CH, Henderson IR. Modification of meiotic recombination by natural variation in plants. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5471-5483. [PMID: 28992351 DOI: 10.1093/jxb/erx306] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Meiosis is a specialized cell division that produces haploid gametes required for sexual reproduction. During the first meiotic division, homologous chromosomes pair and undergo reciprocal crossing over, which recombines linked sequence variation. Meiotic recombination frequency varies extensively both within and between species. In this review, we will examine the molecular basis of meiotic recombination rate variation, with an emphasis on plant genomes. We first consider cis modification caused by polymorphisms at the site of recombination, or elsewhere on the same chromosome. We review cis effects caused by mismatches within recombining joint molecules, the effect of structural hemizygosity, and the role of specific DNA sequence motifs. In contrast, trans modification of recombination is exerted by polymorphic loci encoding diffusible molecules, which are able to modulate recombination on the same and/or other chromosomes. We consider trans modifiers that act to change total recombination levels, hotspot locations, or interactions between homologous and homeologous chromosomes in polyploid species. Finally, we consider the significance of genetic variation that modifies meiotic recombination for adaptation and evolution of plant species.
Collapse
Affiliation(s)
- Emma J Lawrence
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Catherine H Griffin
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Ian R Henderson
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| |
Collapse
|
8
|
Poggio L, Greizerstein E, Ferrari M. Variability in the amount of homoeologous pairing among F1 hybrids. AOB PLANTS 2016; 8:plw030. [PMID: 27255515 PMCID: PMC4925922 DOI: 10.1093/aobpla/plw030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 04/21/2016] [Indexed: 05/24/2023]
Abstract
Genes involved in the exclusive pairing of homologous chromosomes have been described in several polyploid species but little is known about the activity of these genes in diploids (which have only one dose of each homoeologous genome). Analysis of the meiotic behaviour of species, natural and artificial hybrids and polyploids of Glandularia suggests that, in allopolyploids where homoeologous genomes are in two doses, regulator genes prevent homoeologous pairing. The different meiotic phenotypes in diploid F1 hybrids between Glandularia pulchella and Glandularia incisa strongly suggest that these pairing regulator genes possess an incomplete penetrance when homoeologous genomes are in only one dose. Moreover, the meiotic analysis of natural and artificial F1 hybrids suggests that the genetic constitution of parental species influences the activity of pairing regulator genes and is mainly responsible for variability in the amount of homoeologous pairing observed in diploid hybrids. In Glandularia, the pairing regulator genes originated in South American diploid species. The cytogenetic characteristics of this genus make it a good model to analyse and explore in greater depth the activity of pairing regulator genes at different ploidy levels.
Collapse
Affiliation(s)
| | - Eduardo Greizerstein
- Cátedra de Mejoramiento Genético, Facultad de Ciencias Agrarias, Universidad Nacional de Lomas de Zamora (UNLZ), Provincia Buenos Aires, Argentina
| | - María Ferrari
- Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| |
Collapse
|
9
|
Licensing MLH1 sites for crossover during meiosis. Nat Commun 2014; 5:4580. [PMID: 25098240 PMCID: PMC4143925 DOI: 10.1038/ncomms5580] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 07/02/2014] [Indexed: 11/29/2022] Open
Abstract
During meiosis, homologous chromosomes synapse and recombine at sites marked by the binding of the mismatch repair protein MLH1. In hexaploid wheat, the Ph1 locus has a major effect on whether crossover occurs between homologues or between related homoeologues. Here we report that—in wheat–rye hybrids where homologues are absent—Ph1 affects neither the level of synapsis nor the number of MLH1. Thus in the case of wheat–wild relative hybrids, Ph1 must affect whether MLH1 sites are able to progress to crossover. The observed level of synapsis implies that Ph1 functions to promote homologue pairing rather than suppress homoeologue pairing in wheat. Therefore, Ph1 stabilises polyploidy in wheat by both promoting homologue pairing and preventing MLH1 sites from becoming crossovers on paired homoeologues during meiosis. Fertility in polyploid species relies on pairing and recombination occurring only between true homologues rather than the diverged homoeologous chromosomes also present. Here, Martin et al. show that Ph1 stabilises polyploidy in wheat by promoting homologue pairing and preventing crossovers on paired homoeologues during meiosis.
Collapse
|
10
|
Mainiero S, Pawlowski WP. Meiotic chromosome structure and function in plants. Cytogenet Genome Res 2014; 143:6-17. [PMID: 25096046 DOI: 10.1159/000365260] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Chromosome structure is important for many meiotic processes. Here, we outline 3 main determinants of chromosome structure and their effects on meiotic processes in plants. Cohesins are necessary to hold sister chromatids together until the first meiotic division, ensuring that homologous chromosomes and not sister chromatids separate during anaphase I. During meiosis in maize, Arabidopsis, and rice, cohesins are needed for establishing early prophase chromosome structure and recombination and for aligning bivalents at the metaphase plate. Condensin complexes play pivotal roles in controlling the packaging of chromatin into chromosomes through chromatin compaction and chromosome individualization. In animals and fungi, these complexes establish a meiotic chromosome structure that allows for proper recombination, pairing, and synapsis of homologous chromosomes. In plants, information on the role of condensins in meiosis is limited, but they are known to be required for successful completion of reproductive development. Therefore, we speculate that they play roles similar to animal and fungal condensins during meiosis. Plants generally have large and complex genomes due to frequent polyploidy events, and likely, condensins and cohesins organize chromosomes in such a way as to ensure genome stability. Hexaploid wheat has evolved a unique mechanism using a Ph1 locus-controlled chromosome organization to ensure proper chromosome pairing in meiosis. Altogether, studies on meiotic chromosome structure indicate that chromosome organization is not only important for chromatin packaging but also fulfills specific functions in facilitating chromosome interactions during meiosis, including pairing and recombination.
Collapse
Affiliation(s)
- Samantha Mainiero
- Graduate Field of Plant Biology, Cornell University, Ithaca, N.Y., USA
| | | |
Collapse
|
11
|
Guo XH, Bi ZG, Wu BH, Wang ZZ, Hu JL, Zheng YL, Liu DC. ChAy/Bx, a novel chimeric high-molecular-weight glutenin subunit gene apparently created by homoeologous recombination in Triticum turgidum ssp. dicoccoides. Gene 2013; 531:318-25. [DOI: 10.1016/j.gene.2013.08.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 08/14/2013] [Accepted: 08/21/2013] [Indexed: 12/18/2022]
|
12
|
Grandont L, Jenczewski E, Lloyd A. Meiosis and its deviations in polyploid plants. Cytogenet Genome Res 2013; 140:171-84. [PMID: 23817089 DOI: 10.1159/000351730] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Meiosis is a fundamental process in all sexual organisms that ensures fertility and genome stability and creates genetic diversity. For each of these outcomes, the exclusive formation of crossovers between homologous chromosomes is needed. This is more difficult to achieve in polyploid species which have more than 2 sets of chromosomes able to recombine. In this review, we describe how meiosis and meiotic recombination 'deviate' in polyploid plants compared to diploids, and give an overview of current knowledge on how they are regulated. See also the sister article focusing on animals by Stenberg and Saura in this themed issue.
Collapse
Affiliation(s)
- L Grandont
- INRA - Institut Jean Pierre Bourgin, Station de Génétique et Amélioration des Plantes, Versailles, France
| | | | | |
Collapse
|
13
|
Sybenga J. Can epigenetic control explain pronounced within-plant heterogeneity of meiosis in a translocation trisome of Secale L.? Genome 2012; 55:257-64. [PMID: 22409518 DOI: 10.1139/g2012-010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Meiotic metaphase I configuration frequencies were determined in different tillers of genetically related plants of rye ( Secale cereale L.) heterozygous for reciprocal translocation T248W (between chromosome arms 1RS and 6RS) and with an additional (telocentric) arm 1RS. Seventeen different configurations could be recognized, grouped into three categories. Very different configuration frequencies were found not only between sister plants from the same parents but also between tillers of the same plant grown under identical conditions (climate chambers at 15 °C and 20 °C). The heterogeneity reflects variation in chromosome pairing and crossing over, and is variable and unpredictable. Anthers within florets were homogeneous. Between tiller heterogeneity is insufficient to explain differences between sister plants. It is ascribed to random somatic variation in the conditions of the chromatin which, at meiosis, govern chromosome pairing. During sexual differentiation, these conditions are fixed and subsequent cell lineages have the same pairing and crossing over characteristics. As homology search is an activity of DNA, this control of pairing and crossing over, consistent over long cell lineages, may be considered to be epigenetic even when no realistic suggestions concerning its character can be given.
Collapse
Affiliation(s)
- J Sybenga
- Laboratory of Genetics, Wageningen University, Wageningen, the Netherlands.
| |
Collapse
|
14
|
Hao M, Luo J, Yang M, Zhang L, Yan Z, Yuan Z, Zheng Y, Zhang H, Liu D. Comparison of homoeologous chromosome pairing between hybrids of wheat genotypes Chinese Spring ph1b and Kaixian-luohanmai with rye. Genome 2011; 54:959-64. [PMID: 22070394 DOI: 10.1139/g11-062] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The ph-like genes in the Chinese common wheat landrace Kaixian-luohanmai (KL) induce homoeologous pairing in hybrids with alien species. In the present study, meiotic phenotypic differences on homoeologous chromosome pairing at metaphase I between hybrids of wheat genotypes Chinese Spring ph1b (CSph1b) and KL with rye were studied by genomic in situ hybridization (GISH). The frequency of wheat-wheat associations was higher in CSph1b×rye than in KL×rye. However, frequencies of wheat-rye and rye-rye associations were higher in KL×rye than in CSph1b×rye. These differences may be the result of different mechanisms of control between the ph-like gene(s) controlling homoeologous chromosome pairing in KL and CSph1b. Wheat-wheat associations were much more frequent than wheat-rye pairing in both hybriods. This may be caused by lower overall affinity, or homoeology, between wheat and rye chromosomes than between wheat chromosomes.
Collapse
Affiliation(s)
- Ming Hao
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Yousafzai FK, Al-Kaff N, Moore G. The molecular features of chromosome pairing at meiosis: the polyploid challenge using wheat as a reference. Funct Integr Genomics 2010; 10:147-56. [PMID: 20422242 DOI: 10.1007/s10142-010-0171-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 03/18/2010] [Accepted: 03/27/2010] [Indexed: 11/29/2022]
Abstract
During meiosis, chromosome numbers are halved, leading to haploid gametes, a process that is crucial for the maintenance of a stable genome through successive generations. The process for the accurate segregation of the homologues starts in pre-meiosis as each homologue is replicated and the respective products are held together as two sister chromatids via specific cohesion proteins. At the start of meiosis, each chromosome must recognise its homologue from amongst all the chromosomes present in the nucleus and then associate or pair with that homologue. This process of homologue recognition in meiosis is more complicated in polyploids because of the greater number of related chromosomes. Despite the presence of these related chromosomes, for polyploids such as wheat to produce viable gametes, they must behave as diploids during meiosis with only true homologues pairing. In this review, the relationship between the Ph1 cyclin-dependent kinase (CDK)-like genes in wheat and the CDK2 genes in mammals and their involvement in controlling this process at meiosis is examined.
Collapse
|
16
|
Cifuentes M, Grandont L, Moore G, Chèvre AM, Jenczewski E. Genetic regulation of meiosis in polyploid species: new insights into an old question. THE NEW PHYTOLOGIST 2010; 186:29-36. [PMID: 19912546 DOI: 10.1111/j.1469-8137.2009.03084.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Precise chromosome segregation is vital for polyploid speciation. Here, we highlight recent findings that revitalize the old question of the genetic control of diploid-like meiosis behaviour in polyploid species. We first review new information on the genetic control of autopolyploid and allopolyploid cytological diploidization, notably in wheat and Brassica. These major advances provide new opportunities for speculating about the adaptation of meiosis during polyploid evolution. Some of these advances are discussed, and it is suggested that research on polyploidy and on meiosis should no longer be unlinked.
Collapse
Affiliation(s)
- Marta Cifuentes
- Institut Jean Pierre Bourgin, Station de Génétique et Amélioration des Plantes, 78026 Versailles Cedex, France
| | | | | | | | | |
Collapse
|
17
|
Nicolas SD, Leflon M, Monod H, Eber F, Coriton O, Huteau V, Chèvre AM, Jenczewski E. Genetic regulation of meiotic cross-overs between related genomes in Brassica napus haploids and hybrids. THE PLANT CELL 2009; 21:373-85. [PMID: 19190241 PMCID: PMC2660629 DOI: 10.1105/tpc.108.062273] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 12/18/2008] [Accepted: 01/09/2009] [Indexed: 05/18/2023]
Abstract
Although the genetic regulation of recombination in allopolyploid species plays a pivotal role in evolution and plant breeding, it has received little recent attention, except in wheat (Triticum aestivum). PrBn is the main locus that determines the number of nonhomologous associations during meiosis of microspore cultured Brassica napus haploids (AC; 19 chromosomes). In this study, we examined the role played by PrBn in recombination. We generated two haploid x euploid populations using two B. napus haploids with differing PrBn (and interacting genes) activity. We analyzed molecular marker transmission in these two populations to compare genetic changes, which have arisen during meiosis. We found that cross-over number in these two genotypes was significantly different but that cross-overs between nonhomologous chromosomes showed roughly the same distribution pattern. We then examined genetic recombination along a pair of A chromosomes during meiosis of B. rapa x B. napus AAC and AACC hybrids that were produced with the same two B. napus genotypes. We observed significant genotypic variation in cross-over rates between the two AAC hybrids but no difference between the two AACC hybrids. Overall, our results show that PrBn changes the rate of recombination between nonhomologous chromosomes during meiosis of B. napus haploids and also affects homologous recombination with an effect that depends on plant karyotype.
Collapse
Affiliation(s)
- Stéphane D Nicolas
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 118, Amélioration des Plantes et Biotechnologies Végétales, F-35653 Le Rheu, France
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Jenkins G, Phillips D, Mikhailova EI, Timofejeva L, Jones RN. Meiotic genes and proteins in cereals. Cytogenet Genome Res 2008; 120:291-301. [PMID: 18504358 DOI: 10.1159/000121078] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2007] [Indexed: 12/20/2022] Open
Abstract
We review the current status of our understanding and knowledge of the genes and proteins controlling meiosis in five major cereals, rye, wheat, barley, rice and maize. For each crop, we describe the genetic and genomic infrastructure available to investigators, before considering the inventory of genes and proteins that have roles to play in this process. Emphasis is given throughout as to how translational genomic and proteomic approaches have enabled us to circumvent some of the intractable features of this important group of plants.
Collapse
Affiliation(s)
- G Jenkins
- Institute of Biological Sciences, University of Wales, Aberystwyth, UK.
| | | | | | | | | |
Collapse
|
19
|
Naranjo T, Corredor E. Nuclear architecture and chromosome dynamics in the search of the pairing partner in meiosis in plants. Cytogenet Genome Res 2008; 120:320-30. [PMID: 18504361 DOI: 10.1159/000121081] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2007] [Indexed: 10/22/2022] Open
Abstract
The formation of haploid gametes in organisms with sexual reproduction requires regular bivalent chromosome pairing in meiosis. In many species, homologous chromosomes occupy separate territories at the onset of meiosis. To be paired at metaphase I, they need to be brought into a close proximity for interactions that include homology recognition and the establishment of some form of bonds. How homologues find each other is one of the least understood meiotic events. Plant species with large or medium sized genomes, such as wheat or maize, are excellent materials for the cytological analysis of chromosome dynamics at early meiosis, but genes that control meiosis have been identified mainly in small genome species such as Arabidopsis thaliana. This review is focused on the contribution studies on plants are providing to the knowledge of the initial steps of the meiotic process.
Collapse
Affiliation(s)
- T Naranjo
- Departamento de Genética, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain.
| | | |
Collapse
|
20
|
Epigenetic control may explain large within-plant heterogeneity of meiotic behavior in telocentric trisomics of rye. Genetics 2008; 178:1915-26. [PMID: 18430925 DOI: 10.1534/genetics.108.087643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In telocentric trisomics (telotrisomics) of organisms in which the chromosomes normally have two distinct arms, a single chromosome arm with a centromere is present in addition to a complete diploid set of chromosomes. It is the simplest form of polysomy and suitable for analyzing meiotic pairing and recombination patterns in situations where chromosomes compete for pairing. When no suitable meiotic chromosome markers are available, four metaphase I configurations can be distinguished. Their relative frequencies are indicative of the pairing and recombination patterns. In short arm (1RS) telotrisomics of chromosome 1R of rye (Secale cereale) we observed great differences in pairing and recombination patterns among spikes from different tillers and clones of the same plants. Anthers within spikes were only very rarely different. We analyzed a large number of genotypes, including inbreds as well as hybrids. The effects of genetic and environmental conditions on heterogeneity, if any, were limited. Considering that the reproductive tissue of a spike is derived from one primordial cell, it seems that at the start of sexual differentiation there was variation among cells in chromosomal control, which at meiosis determines pairing and crossing-over competence. We suggest that it is an epigenetic system that rigidly maintains this pattern through generative differentiation. In competitive situations the combination most competent for pairing will pair preferentially, forming specific meiotic configurations with different frequencies for different spikes of the same plant. This would explain the heterogeneity between spikes and the homogeneity within spikes. The epigenetic system could involve chromatin conformation or DNA methylation. There were no signs of heterochromatinization.
Collapse
|
21
|
Kopecky D, Allen DC, Duchoslav M, Dolezel J, Lukaszewski AJ. Condensation of rye chromatin in somatic interphase nuclei of Ph1 and ph1b wheat. Cytogenet Genome Res 2008; 119:263-7. [PMID: 18253040 DOI: 10.1159/000112072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2007] [Indexed: 11/19/2022] Open
Abstract
The Ph1 locus in hexaploid wheat (Triticum aestivum L.) enforces diploid-like behavior in the first metaphase of meiosis. To test the hypothesis that this chromosome pairing control is exercised by affecting the degree of chromatin condensation, the dispersion of rye chromatin in interphase nuclei in somatic tissues of wheat-rye chromosome translocations 1RS.1BL, 2RS.2BL, 2BS.2RL, 3RS.3DL and 5RS.5BL was compared in Ph1 and ph1b isogenic backgrounds. No significant differences in rye chromatin condensation that could be attributed to the Ph1 locus were detected. Regardless of the Ph1 status, each rye chromosome arm tested conformed to the general Rabl's orientation and occupied portions of the nuclei proportional to their length. Earlier observations that indicated the involvement of Ph1 locus in rye chromatin condensation in wheat could have been due either to specific loci on the studied 5RL rye arm that control the chromosome condensation process or to damage to the genetic system controlling chromatin condensation in the existing ph1b stocks of wheat. That damage might have been caused by homoeologous recombination and uneven disjunction of chromosomes from multivalents.
Collapse
Affiliation(s)
- D Kopecky
- Institute of Experimental Botany, Olomouc, Czech Republic
| | | | | | | | | |
Collapse
|
22
|
Corredor E, Lukaszewski AJ, Pachón P, Allen DC, Naranjo T. Terminal regions of wheat chromosomes select their pairing partners in meiosis. Genetics 2007; 177:699-706. [PMID: 17720899 PMCID: PMC2034636 DOI: 10.1534/genetics.107.078121] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many plant species, including important crops like wheat, are polyploids that carry more than two sets of genetically related chromosomes capable of meiotic pairing. To safeguard a diploid-like behavior at meiosis, many polyploids evolved genetic loci that suppress incorrect pairing and recombination of homeologues. The Ph1 locus in wheat was proposed to ensure homologous pairing by controlling the specificity of centromere associations that precede chromosome pairing. Using wheat chromosomes that carry rye centromeres, we show that the centromere associations in early meiosis are not based on homology and that the Ph1 locus has no effect on such associations. Although centromeres indeed undergo a switch from nonhomologous to homologous associations in meiosis, this process is driven by the terminally initiated synapsis. The centromere has no effect on metaphase I chiasmate chromosome associations: homologs with identical or different centromeres, in the presence and absence of Ph1, pair the same. A FISH analysis of the behavior of centromeres and distal chromomeres in telocentric and bi-armed chromosomes demonstrates that it is not the centromeric, but rather the subtelomeric, regions that are involved in the correct partner recognition and selection.
Collapse
Affiliation(s)
- Eduardo Corredor
- Departamento de Genética, Facultad de Biología, Universidad Complutense, 28040 Madrid, Spain
| | | | | | | | | |
Collapse
|
23
|
Corredor E, Naranjo T. Effect of colchicine and telocentric chromosome conformation on centromere and telomere dynamics at meiotic prophase I in wheat-rye additions. Chromosome Res 2007; 15:231-45. [PMID: 17308890 DOI: 10.1007/s10577-006-1117-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 11/30/2006] [Accepted: 11/30/2006] [Indexed: 10/23/2022]
Abstract
Association of telomeres in a bouquet and clustering of centromere regions have been proposed to be involved in the search and recognition of homologous partners. We have analysed the role of these structures in meiotic chromosome pairing in wheat-rye addition lines by applying colchicine for disturbing presynaptic telomere movements and by modifying the centromere position from submetacentric to telocentric for studying centromere effects. Rye chromosomes, wheat and rye centromeres, and telomeres were identified by fluorescence in-situ hybridization. Presynaptic association of centromeres in pairs or in more complex structures involved mainly non-homologous chromosomes as deduced from the behaviour of rye centromeres. While centromere association was not affected by colchicine, colchicine inhibited bouquet formation, which caused failure of homologous synapsis. Homologous centromeres of rye telocentrics associated earlier than those of rye submetacentric chromosomes, indicating that migration of the telocentrics' centromeres to the telomere pole during bouquet formation facilitated their association. Homologous chromosomes associated in premeiotic interphase can recognize each other and initiate synapsis at zygotene. However, telomere convergence is needed for bringing together the majority of homologous pairs that normally occupy separate territories in premeiotic nuclei.
Collapse
Affiliation(s)
- Eduardo Corredor
- Departamento de Genética, Facultad de Biología, Universidad Complutense, 28040, Madrid, Spain
| | | |
Collapse
|
24
|
Zickler D. From early homologue recognition to synaptonemal complex formation. Chromosoma 2006; 115:158-74. [PMID: 16570189 DOI: 10.1007/s00412-006-0048-6] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 12/20/2005] [Accepted: 12/21/2005] [Indexed: 10/24/2022]
Abstract
This review focuses on various aspects of chromosome homology searching and their relationship to meiotic and vegetative pairing and to the silencing of unpaired copies of genes. Chromosome recognition and pairing is a prominent characteristic of meiosis; however, for some organisms, this association (complete or partial) is also a normal part of nuclear organization. The multiple mechanisms suggested to contribute to homologous pairing are analyzed. Recognition of DNA/DNA homology also plays an important role in detecting DNA segments that are present in inappropriate number of copies before and during meiosis. In this context, the mechanisms of methylation induced premeiotically, repeat-induced point mutation, meiotic silencing by unpaired DNA, and meiotic sex chromosome inactivation will be discussed. Homologue juxtaposition during meiotic prophase can be divided into three mechanistically distinct steps, namely, recognition, presynaptic alignment, and synapsis by the synaptonemal complex (SC). In most organisms, these three steps are distinguished by their dependence on DNA double-strand breaks (DSBs). The coupling of SC initiation to (and downstream effects of) DSB formation and the exceptions to this dependency are discussed. Finally, this review addresses the specific factors that appear to promote chromosome movement at various stages of meiotic prophase, most particularly at the bouquet stage, and on their significance for homologue pairing and/or achieving a final pachytene configuration.
Collapse
Affiliation(s)
- Denise Zickler
- Université Paris-Sud, Institut de Génétique et Microbiologie, 91405, Orsay, France.
| |
Collapse
|
25
|
Chang SB, de Jong H. Production of alien chromosome additions and their utility in plant genetics. Cytogenet Genome Res 2005; 109:335-43. [PMID: 15753594 DOI: 10.1159/000082417] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2003] [Accepted: 02/25/2004] [Indexed: 11/19/2022] Open
Abstract
Breeding programs aiming at transferring desirable genes from one species to another through interspecific hybridization and backcrossings often produce monosomic and disomic additions as intermediate crossing products. Such aneuploids contain alien chromosomes added to the complements of the recipient parent and can be used for further introgression programs, but lack of homoeologous recombination and inevitable segregation of the alien chromosome at meiosis make them often less ideal for producing stable introgression lines. Monosomic and disomic additions can have specific morphological characteristics, but more often they need additional confirmation of molecular marker analyses and assessment by fluorescence in situ hybridization with genomic and chromosome-specific DNA as probes. Their specific genetic and cytogenetic properties make them powerful tools for fundamental research elucidating regulation of homoeologous recombination, distribution of chromosome-specific markers and repetitive DNA sequences, and regulation of heterologous gene expression. In this overview we present the major characteristics of such interspecific aneuploids highlighting their advantages and drawbacks for breeding and fundamental research.
Collapse
Affiliation(s)
- S-B Chang
- Laboratory of Genetics, Wageningen University, Wageningen, The Netherlands
| | | |
Collapse
|
26
|
Lyusikov OM, Bel’ko NB, Shchet’ko IS, Gordei IA. Construction of Rye-Wheat Amphidiploids with the Cytoplasm of Rye—Secalotriticum (RRAABB, 2n = 42): Meiosis Characteristics in Rye-Triticale F1 Hybrids (RRABR, 5x = 35). RUSS J GENET+ 2005. [DOI: 10.1007/s11177-005-0153-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
27
|
Corredor E, Díez M, Shepherd K, Naranjo T. The positioning of rye homologous chromosomes added to wheat through the cell cycle in somatic cells untreated and treated with colchicine. Cytogenet Genome Res 2005; 109:112-9. [PMID: 15753566 DOI: 10.1159/000082389] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Accepted: 01/22/2004] [Indexed: 12/31/2022] Open
Abstract
The arrangement of chromosome pairs 5RL and 7R added to the wild type and the ph1b mutant line of hexaploid wheat are analyzed in 2N somatic root tip cells during the cell cycle relative to the arrangement that chromosomes 5RL show in 4N tapetal cells produced after colchicine treatment. Both homologous chromosome pairs are identified at interphase and mitosis by fluorescence in situ hybridization. In nuclei at interphase, chromosomes appear as discrete domains that show the Rabl orientation. Homologous chromosomes are predominantly non-associated and their positioning seems not to be influenced by the Ph1 gene that suppresses homoeologous meiotic pairing. This pattern of arrangement contrasts with the high level of somatic pairing that sister chromosomes show in the interphase that follows chromosome duplication induced by colchicine. Disruption of pairing observed in some 4N nuclei is produced at c-anaphase which suggests no topological redistribution of homologues during conformation of the new nucleus. Homologous chromosomes show no predominant arrangement in ellipsoidal metaphase plates, which contrasts with the preferential opposite location of homologues in human prometaphase rosettes. Differences between chromosomes in the variation of the length through the cell cycle and in the chromatin morphology when the Ph1 is absent suggest different patterns of chromatin condensation in both chromosomes.
Collapse
Affiliation(s)
- E Corredor
- Departamento de Genética, Facultad de Biología, Universidad Complutense, Madrid, Spain
| | | | | | | |
Collapse
|
28
|
McKee BD. Homologous pairing and chromosome dynamics in meiosis and mitosis. ACTA ACUST UNITED AC 2004; 1677:165-80. [PMID: 15020057 DOI: 10.1016/j.bbaexp.2003.11.017] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Revised: 11/18/2003] [Indexed: 10/26/2022]
Abstract
Pairing of homologous chromosomes is an essential feature of meiosis, acting to promote high levels of recombination and to ensure segregation of homologs. However, homologous pairing also occurs in somatic cells, most regularly in Dipterans such as Drosophila, but also to a lesser extent in other organisms, and it is not known how mitotic and meiotic pairing relate to each other. In this article, I summarize results of recent molecular studies of pairing in both mitosis and meiosis, focusing especially on studies using fluorescent in situ hybridization (FISH) and GFP-tagging of single loci, which have allowed investigators to assay the pairing status of chromosomes directly. These approaches have permitted the demonstration that pairing occurs throughout the cell cycle in mitotic cells in Drosophila, and that the transition from mitotic to meiotic pairing in spermatogenesis is accompanied by a dramatic increase in pairing frequency. Similar approaches in mammals, plants and fungi have established that with few exceptions, chromosomes enter meiosis unpaired and that chromosome movements involving the telomeric, and sometimes centromeric, regions often precede the onset of meiotic pairing. The possible roles of proteins involved in homologous recombination, synapsis and sister chromatid cohesion in homolog pairing are discussed with an emphasis on those for which mutant phenotypes have permitted an assessment of effects on homolog pairing. Finally, I consider the question of the distribution and identity of chromosomal pairing sites, using recent data to evaluate possible relationships between pairing sites and other chromosomal sites, such as centromeres, telomeres, promoters and heterochromatin. I cite evidence that may point to a relationship between matrix attachment sites and homologous pairing sites.
Collapse
Affiliation(s)
- Bruce D McKee
- Department of Biochemistry and Cellular and Molecular Biology and Genome Sciences and Technology Program, University of Tennessee, Knoxville, M407 Walters Life Sciences Building, Knoxville, TN 37996-0840, USA.
| |
Collapse
|
29
|
Naranjo T, Corredor E. Clustering of centromeres precedes bivalent chromosome pairing of polyploid wheats. TRENDS IN PLANT SCIENCE 2004; 9:214-7. [PMID: 15130545 DOI: 10.1016/j.tplants.2004.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Affiliation(s)
- Tomás Naranjo
- Departamento de Genética, Facultad de Biología, Universidad Complutense, 28040 Madrid, Spain.
| | | |
Collapse
|
30
|
Abstract
In situ hybridization is a powerful and unique technique that correlates molecular information of a DNA sequence with its physical location along chromosomes and genomes. It thus provides valuable information about physical map position of sequences and often is the only means to determine abundance and distribution of repetitive sequences making up the majority of most genomes. Repeated DNA sequences, composed of units of a few to a thousand base pairs in size, occur in blocks (tandem or satellite repeats) or are dispersed (including transposable elements) throughout the genome. They are often the most variable components of a genome, often being species and, occasionally, chromosome specific. Their variability arises through amplification, diversification and dispersion, as well as homogenization and loss; there is a remarkable correlation of molecular sequence features with chromosomal organization including the length of repeat units, their higher order structures, chromosomal locations, and dispersion mechanisms. Our understanding of the structure, function, organization, and evolution of genomes and their evolving repetitive components enabled many new cytogenetic applications to both medicine and agriculture, particularly in diagnosis and plant breeding.Key words: repetitive DNA, genome organization, sequence evolution, telomere, centromere.
Collapse
|
31
|
Sutton T, Whitford R, Baumann U, Dong C, Able JA, Langridge P. The Ph2 pairing homoeologous locus of wheat (Triticum aestivum): identification of candidate meiotic genes using a comparative genetics approach. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 36:443-56. [PMID: 14617076 DOI: 10.1046/j.1365-313x.2003.01891.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Colinearity in gene content and order between rice and closely related grass species has emerged as a powerful tool for gene identification. Using a comparative genetics approach, we have identified the rice genomic region syntenous to the region deleted in the wheat chromosome pairing mutant ph2a, with a view to identifying genes at the Ph2 locus that control meiotic processes. Utilising markers known to reside within the region deleted in ph2a, and data from wheat, barley and rice genetic maps, markers delimiting the region deleted on wheat chromosome 3DS in the ph2a mutant were used to locate the syntenous region on the short arm of rice chromosome 1. A contig of rice genomic sequence was identified from publicly available sequence information and used in blast searches to identify wheat expressed sequence tags (ESTs) exhibiting significant similarity. Southern analysis using a subset of identified wheat ESTs confirmed a syntenous relationship between the rice and wheat genomic regions and defined precisely the extent of the deleted segment in the ph2a mutant. A 6.58-Mb rice contig generated from 60 overlapping rice chromosome 1 P1 artificial chromosome (PAC) clones spanning the syntenous rice region has enabled identification of 218 wheat ESTs putatively located in the region deleted in ph2a. What seems to be a terminal deletion on chromosome 3DS is estimated to be 80 Mb in length. Putative candidate genes that may contribute to the altered meiotic phenotype of ph2a are discussed.
Collapse
Affiliation(s)
- Tim Sutton
- Molecular Plant Breeding Cooperative Research Centre, School of Agriculture and Wine, The University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia.
| | | | | | | | | | | |
Collapse
|
32
|
Maestra B, Hans de Jong J, Shepherd K, Naranjo T. Chromosome arrangement and behaviour of two rye homologous telosomes at the onset of meiosis in disomic wheat-5RL addition lines with and without the Ph1 locus. Chromosome Res 2003; 10:655-67. [PMID: 12575794 DOI: 10.1023/a:1021564327226] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Fluorescence in-situ hybridization (FISH) of total genomic and repetitive DNA on microsporocytes of ditelocentric addition lines of rye 5RL in hexaploid wheat was performed to study the behaviour of the rye homologous chromosome arms in relation to centromere and telomere dynamics at premeiotic interphase and meiotic prophase I. By comparing isogenic lines with and without the Ph1 locus, we established the effect of the Ph1 gene on appearance and behaviour of the rye chromosomes. Ph1 and ph1b lines demonstrated similar premeiotic chromosome arrangement with the two rye homologues occupying separated domains despite the occurrence of centromere association. Our study confirmed that bouquet arrangement of telomeres follows the Rabl configuration. In cells displaying bouquet clustering of telomeres, centromeres of the 5RL telosomes are still at the opposite pole, suggesting anchoring of centromeres at the cytoskeleton. Once the telomeres complete clustering, the rye centromeres migrate to the telomere pole, and the rye chromosomes begin to loosen their structure. While the rye homologues in the wild-type keep separate territories in the nucleus, they become intermingled in the ph1b mutant, possibly because of their lower condensation. In a subsequent stage, the 5RL homologues appear intimately associated mainly at the distal region. Our study suggests that the lower rate of chromosome synapsis in the ph1b mutant results from abnormal chromatin decondensation and organization.
Collapse
Affiliation(s)
- Belén Maestra
- Departamento de Genética, Facultad de Biología, Universidad Complutense, 28040 Madrid, Spain
| | | | | | | |
Collapse
|
33
|
Schwarzacher T. Meiosis, recombination and chromosomes: a review of gene isolation and fluorescent in situ hybridization data in plants. JOURNAL OF EXPERIMENTAL BOTANY 2003; 54:11-23. [PMID: 12456751 DOI: 10.1093/jxb/erg042] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Evidence is now increasing that many functions and processes of meiotic genes are similar in yeast and higher eukaryotes. However, there are significant differences and, most notably, yeast has considerably higher recombination frequencies than higher eukaryotes, different cross-over interference and possibly more than one pathway for recombination, one late and one early. Other significant events are the timing of double-strand breaks (induced by Spo11) that could be either cause or consequence of homologous chromosome synapsis and SC formation depending on the organisms, yeast plants and mammals versus Drosophila melanogaster and Caenorhabditis elegans. Many plant homologues and heterologues to meiotic genes of yeast and other organisms have now been isolated, in particular in Arabidopsis thaliana, showing that overall recombination genes are very conserved while synaptonemal complex and cohesion proteins are not. In addition to the importance of unravelling the meiotic processes by gene discovery, this review discusses the significance of chromatin packaging, genome organization, and distribution of specific repeated DNA sequences for homologous chromosome cognition and pairing, and the distribution of recombination events along the chromosomes.
Collapse
Affiliation(s)
- Trude Schwarzacher
- Department of Biology, University of Leicester, University Road, Leicester LE1 7RH, UK.
| |
Collapse
|
34
|
Abstract
Polyploids possess two or more sets of related chromosomes as a result of either the doubling of chromosomes following sexual hybridization within the same species (autopolyploidy), or between closely related species containing related but not completely homologous (homoeologous) genomes (allopolyploidy). For allopolyploids to produce viable gametes and be fertile, they must behave as diploids during meiosis, so that only identical chromosomes (homologues) pair. A solution to this problem is an enhanced ability to resolve incorrect pairing, which in turn promotes correct pairing. This gives nonhomologous chromosomes an almost 'Teflon'-like status, so that only the correct pairs 'stick'.
Collapse
Affiliation(s)
- Graham Moore
- John Innes Centre, Norwich Research Park, Colney, Norwich, UK NR4 7UH.
| |
Collapse
|
35
|
Armstrong SJ, Franklin FC, Jones GH. Nucleolus-associated telomere clustering and pairing precede meiotic chromosome synapsis in Arabidopsis thaliana. J Cell Sci 2001; 114:4207-17. [PMID: 11739653 DOI: 10.1242/jcs.114.23.4207] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intranuclear arrangements of centromeres and telomeres during meiotic interphase and early prophase I of meiosis in Arabidopsis thaliana were analysed by fluorescent in situ hybridisation to spread pollen mother cells and embryo-sac mother cells. Meiocyte identification, staging and progression were established by spreading and sectioning techniques, including various staining procedures and bromodeoxyuridine labeling of replicating DNA.
Centromere regions of Arabidopsis are unpaired, widely dispersed and peripherally located in nuclei during meiotic interphase, and they remain unpaired and unassociated throughout leptotene. Eventually they associate pairwise during zygotene, as part of the nucleus-wide synapsis of homologous chromosomes.
Telomeres, by contrast, show a persistent association with the nucleolus throughout meiotic interphase. Variation in telomere signal number indicates that telomeres undergo pairing during this interval, preceding the onset of general chromosome synapsis. During leptotene the paired telomeres lose their association with the nucleolus and become widely dispersed. As the chromosomes synapse during zygotene, the telomeres reveal a loose clustering within one hemisphere, which may represent a degenerate or relic bouquet configuration. We propose that in Arabidopsis the classical leptotene/zygotene bouquet is absent and is replaced functionally by nucleolus-associated telomere clustering.
Collapse
Affiliation(s)
- S J Armstrong
- School of Biosciences, The University of Birmingham, Birmingham B15 2TT, UK
| | | | | |
Collapse
|
36
|
Mikhailova EI, Sosnikhina SP, Kirillova GA, Tikholiz OA, Smirnov VG, Jones RN, Jenkins G. Nuclear dispositions of subtelomeric and pericentromeric chromosomal domains during meiosis in asynaptic mutants of rye (Secale cereale L.). J Cell Sci 2001; 114:1875-82. [PMID: 11329374 DOI: 10.1242/jcs.114.10.1875] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nuclear dispositions of subtelomeric and pericentromeric domains in pollen mother cells (PMCs) were tracked during meiosis in wildtype and two asynaptic mutants of rye (Secale cereale L.) by means of fluorescence in situ hybridization (FISH). Homozygotes for sy1 and sy9 non-allelic mutations form axial elements during leptotene of male meiosis, but fail to form synaptonemal complexes. Consequently, recombination is severely impaired, and high univalency is observed at metaphase I. Simultaneous FISH with pSc200 subtelomeric tandem repeat and CCS1 centromeric sequence revealed that at pre-meiotic interphase the two domains are in a bipolar Rabl orientation in both the PMCs and tapetal cells. At the onset of meiotic prophase, the subtelomeric regions in PMCs of wildtype and sy9 cluster into a typical bouquet conformation. The timing of this event in rye is comparable with that in wheat, and is earlier than that observed in other organisms, such as maize, yeast and mammals. This arrangement is retained until later in leptotene and zygotene when the pericentromeric domains disperse and the subtelomeric clusters fragment. The mutant phenotype of sy9 manifests itself during leptotene to zygotene, when the pericentromeric regions become distinctly more distended than in wildtype, and largely fail to pair during zygotene. This indicates that difference in the nature or timing of chromosome condensation in this region is the cause or consequence of asynapsis. By contrast, sy1 fails to form comparable aggregates of subtelomeric regions at leptotene in only half of the nuclei studied. Instead, two to five aggregates are formed that fail to disperse at later stages of meiotic prophase. In addition, the pericentromeric regions disperse prematurely at leptotene and do not associate in pairs at any subsequent stage. It is supposed that the sy1 mutation could disrupt the nuclear disposition of centromeres and telomeres at the end of pre-meiotic interphase, which could cause, or contribute to, its asynaptic phenotype.
Collapse
Affiliation(s)
- E I Mikhailova
- Dept of Genetics, Saint-Petersburg State University, Russia
| | | | | | | | | | | | | |
Collapse
|
37
|
Qi L, Friebe B, Gill BS. Meiotic metaphase I pairing behavior of a 5BL recombinant isochromosome in wheat. Chromosome Res 2001; 8:671-6. [PMID: 11196130 DOI: 10.1023/a:1026785119376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A recombinant isochromosome i5BLrec of wheat was developed with one arm and the proximal 36% of the other arm of Chinese Spring (CS) origin and the distal 64% of the recombined arm of Triticum turgiduM subsp. dicoccoides origin. The i5BLrec provides an unusual opportunity to analyze the role of the centromere or arm heterozygosity in chromosome prealignment and synapsis during meiosis. In monosomic condition, the i5BLrec formed a ring univalent in 86.8% of the pollen mother cells (PMCs) at meiotic metaphase I. In the disomic condition, the two i5BLrec preferentially paired as a normal bivalent in 74.8% of the PMCs, which differed significantly (p <0.01) from the normal bivalent pairing of 51% observed in diisosomic 5BL chromosomes of the CS (Di5BL(CS)) control plants. In plants with one i5BLrec and a normal 5B(CS), the long arm of 5B(CS) paired with the homologous arm of i5BLrec in 54.4% of the PMCs, and 40.4% of the PMCs had a 5B(CS) univalent and a i5BLrec ring univalent. The implications of the i5BLrec pairing data on the mechanism of Ph1 gene action are discussed.
Collapse
Affiliation(s)
- L Qi
- Department of Plant Pathology, Kansas State University, Manhattan 66506-5502, USA
| | | | | |
Collapse
|
38
|
Manzanero S, Puertas MJ, Jiménez G, Vega JM. Neocentric activity of rye 5RL chromosome in wheat. Chromosome Res 2001; 8:543-54. [PMID: 11032323 DOI: 10.1023/a:1009275807397] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The neocentric activity of a constriction located on the long arm of rye 5R chromosome (5RL) was analysed. It is not observed in normal rye but it is unusually stretched in bivalents involving 5RL telosomes in wheat-ditelosomic 5RL addition lines. In 20% of metaphase I cells, the 5RL bivalent presents the centromeres oriented to one pole and the constrictions oriented towards the opposite pole with a strong tension. In 5% of the cells, the constriction was able to orient the bivalent to the poles without tension in the centromeres. Sister chromatid cohesion, which is one of the distinct features of centromeric function, is persistent at the constriction in delayed 5RL chromosomes at anaphase I. Neither the elongation of the constriction nor the neocentric activity was observed at second meiotic division or mitosis. FISH studies showed that the 5RL constriction lacked detectable quantities of two repetitive DNA sequences, CCS1 and the 180-bp knob repeat, present at cereal centromeres and neocentromeres, respectively. We propose that, under special conditions, such as the wheat background, the normally non-centromeric DNA present at this region of 5RL acquires a specific chromatin structure, differentiated as an elongated constriction, which is able to function as a centromere.
Collapse
Affiliation(s)
- S Manzanero
- Departamento de Genética, Facultad de Biología, Universidad Complutense, Madrid, Spain
| | | | | | | |
Collapse
|
39
|
Schubert I, Fransz PF, Fuchs J, de Jong JH. Chromosome painting in plants. METHODS IN CELL SCIENCE : AN OFFICIAL JOURNAL OF THE SOCIETY FOR IN VITRO BIOLOGY 2001. [PMID: 11741144 DOI: 10.1007/978-94-010-0330-8_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in situ suppression' (CISS) hybridisation with chromosome-derived DNA probes and blocking of interchromosomally dispersed repeats by total genomic or C0t-1 DNA in excess, iii) exceptional cases of single chromosome painting by probes containing chromosome-specific dispersed repeats, and iv) Fluorescence in situ hybridisation (FISH) with extended contigs of large insert clones for painting of those chromosomes of a euploid complement which harbour the cloned sequences. While GISH was successfully applied in most plant hybrids and/or their derivatives, painting of individual chromosomes by CISS hybridisations of chromosome-specific DNA probes have so far not revealed convincing results in plants. The reason for this failure and the use of possible alternative approaches are discussed. At least for small plant genomes, painting by large insert single sequence clones provides a promising alternative tool to solve cytogenetic questions, which up to now could not be tackled otherwise. An example of such a painting is described in detail for Arabidopsis thaliana.
Collapse
Affiliation(s)
- I Schubert
- Institute of Plant Genetics and Crop Plant Research (IPK), D-06466 Gatersleben, Germany.
| | | | | | | |
Collapse
|
40
|
Wang ZN, Hang A, Hansen J, Burton C, Mallory-Smith CA, Zemetra RS. Visualization of A- and B-genome chromosomes in wheat (Triticum aestivum L.) x jointed goatgrass (Aegilops cylindrica Host) backcross progenies. Genome 2000; 43:1038-44. [PMID: 11195336 DOI: 10.1139/g00-080] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Wheat (Triticum aestivum) and jointed goatgrass (Aegilops cylindrica) can cross with each other, and their self-fertile backcross progenies frequently have extra chromosomes and chromosome segments, presumably retained from wheat, raising the possibility that a herbicide resistance gene might transfer from wheat to jointed goatgrass. Genomic in situ hybridization (GISH) was used to clarify the origin of these extra chromosomes. By using T. durum DNA (AABB genome) as a probe and jointed goatgrass DNA (CCDD genome) as blocking DNA, one, two, and three A- or B-genome chromosomes were identified in three BC2S2 individuals where 2n = 29, 30, and 31 chromosomes, respectively. A translocation between wheat and jointed goatgrass chromosomes was also detected in an individual with 30 chromosomes. In pollen mother cells with meiotic configuration of 14 II + 2 I, the two univalents were identified as being retained from the A or B genome of wheat. By using Ae. markgrafii DNA (CC genome) as a probe and wheat DNA (AABBDD genome) as blocking DNA. 14 C-genome chromosomes were visualized in all BC2S2 individuals. The GISH procedure provides a powerful tool to detect the A or B-genome chromatin in a jointed goatgrass background, making it possible to assess the risk of transfer of herbicide resistance genes located on the A or B genome of wheat to jointed goatgrass.
Collapse
Affiliation(s)
- Z N Wang
- Department of Plant, Soil, and Entomological Sciences, University of Idaho, Moscow 83844-2339, USA.
| | | | | | | | | | | |
Collapse
|
41
|
Abstract
Meiotic chromosomes have been studied for many years, in part because of the fundamental life processes they represent, but also because meiosis involves the formation of homolog pairs, a feature which greatly facilitates the study of chromosome behavior. The complex events involved in homolog juxtaposition necessitate prolongation of prophase, thus permitting resolution of events that are temporally compressed in the mitotic cycle. Furthermore, once homologs are paired, the chromosomes are connected by a specific structure: the synaptonemal complex. Finally, interaction of homologs includes recombination at the DNA level, which is intimately linked to structural features of the chromosomes. In consequence, recombination-related events report on diverse aspects of chromosome morphogenesis, notably relationships between sisters, development of axial structure, and variations in chromatin status. The current article reviews recent information on these topics in an historical context. This juxtaposition has suggested new relationships between structure and function. Additional issues were addressed in a previous chapter (551).
Collapse
Affiliation(s)
- D Zickler
- Institut de Génétique et Microbiologie, Université Paris-Sud, Orsay, France.
| | | |
Collapse
|
42
|
Korzun V, Borner A, Siebert R, Malyshev S, Hilpert M, Kunze R, Puchta H. Chromosomal location and genetic mapping of the mismatch repair gene homologs MSH2, MSH3, and MSH6 in rye and wheat. Genome 1999; 42:1255-7. [PMID: 10659795 DOI: 10.1139/g99-081] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The efficiency of homeologous recombination is influenced by mismatch repair genes in bacteria, yeast, and mammals. To elucidate a possible role of these genes in homeologous pairing and cross-compatibility in plants, gene probes of wheat (Triticum aestivum) specific for the mismatch repair gene homologues MSH2, MSH3, and MSH6 were used to map them to their genomic positions in rye (Secale cereale). Whereas MSH2 was mapped to the short arm of chromosome 1R, MSH3 was mapped to the long arm of chromosome 2R and MSH6 to the long arm of chromosome 5R. Southern blots with nullisomic-tetrasomic (NT) lines of wheat indicated the presence of the sequences on the respective homeologous group of wheat chromosomes. Additionally, an MSH6-specific homologue could also be detected on homoeologous group 3 of wheat. However, in the well-known, highly homoeologous pairing wheat mutant ph1b the MSH6-specific sequence is not within the deleted part of chromosome 5BL, indicating that the pairing phenotype is not due to a loss of one of the mismatch repair genes tested.
Collapse
Affiliation(s)
- V Korzun
- Institut fur Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany.
| | | | | | | | | | | | | |
Collapse
|
43
|
Martínez-Pérez E, Shaw P, Reader S, Aragón-Alcaide L, Miller T, Moore G. Homologous chromosome pairing in wheat. J Cell Sci 1999; 112 ( Pt 11):1761-9. [PMID: 10318768 DOI: 10.1242/jcs.112.11.1761] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bread wheat is a hexaploid (AABBDD, 2n=6x=42) containing three related ancestral genomes, each having 7 chromosomes, giving 42 chromosomes in diploid cells. During meiosis true homologues are correctly associated in wild-type wheat, but a degree of association of related chromosomes (homoeologues) occurs in a mutant (ph1b). We show that the centromeres are associated in non-homologous pairs in all floral tissues studied, both in wild-type wheat and the ph1b mutant. The non-homologous centromere associations then become homologous premeiotically in wild-type wheat in both meiocytes and the tapetal cells, but not in the mutant. In wild-type wheat, the homologues are colocalised along their length at this stage, but the telomeres remain distinct. A single telomere cluster (bouquet) is formed in the meiocytes only by the onset of leptotene. The sub-telomeric regions of the homologues associate as the telomere cluster forms. The homologous associations at the telomeres and centromeres are maintained through meiotic prophase, although, during leptotene, the two homologues and also the sister chromatids within each homologue are separate along the rest of their length. As meiosis progresses, first the sister chromatids and then the homologues associate intimately. In wild-type wheat, first the centromere grouping, then the bouquet disperse by the end of zygotene.
Collapse
|