1
|
Lenykó-Thegze A, Fábián A, Mihók E, Makai D, Cseh A, Sepsi A. Pericentromeric chromatin reorganisation follows the initiation of recombination and coincides with early events of synapsis in cereals. Plant J 2021; 107:1585-1602. [PMID: 34171148 DOI: 10.1111/tpj.15391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/04/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
The reciprocal exchange of genetic information between homologous chromosomes during meiotic recombination is essential to secure balanced chromosome segregation and to promote genetic diversity. The chromosomal position and frequency of reciprocal genetic exchange shapes the efficiency of breeding programmes and influences crop improvement under a changing climate. In large genome cereals, such as wheat and barley, crossovers are consistently restricted to subtelomeric chromosomal regions, thus preventing favourable allele combinations being formed within a considerable proportion of the genome, including interstitial and pericentromeric chromatin. Understanding the key elements driving crossover designation is therefore essential to broaden the regions available for crossovers. Here, we followed early meiotic chromatin dynamism in cereals through the visualisation of a homologous barley chromosome arm pair stably transferred into the wheat genetic background. By capturing the dynamics of a single chromosome arm at the same time as detecting the undergoing events of meiotic recombination and synapsis, we showed that subtelomeric chromatin of homologues synchronously transitions to an open chromatin structure during recombination initiation. By contrast, pericentromeric and interstitial regions preserved their closed chromatin organisation and become unpackaged only later, concomitant with initiation of recombinatorial repair and the initial assembly of the synaptonemal complex. Our results raise the possibility that the closed pericentromeric chromatin structure in cereals may influence the fate decision during recombination initiation, as well as the spatial development of synapsis, and may also explain the suppression of crossover events in the proximity of the centromeres.
Collapse
Affiliation(s)
- Andrea Lenykó-Thegze
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Attila Fábián
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Edit Mihók
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Diána Makai
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - András Cseh
- Department of Molecular Breeding, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Adél Sepsi
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
- Department of Applied Biotechnology and Food Science (ABÉT), BME, Budapest University of Technology and Economics, Műegyetem rkp. 3-9, Budapest, 1111, Hungary
| |
Collapse
|