Skip to Main content Skip to Navigation
Journal articles

SPO11.2 is essential for programmed double‐strand break formation during meiosis in bread wheat ( Triticum aestivum L.)

Abstract : Meiotic recombination is initiated by formation of DNA double-strand breaks (DSBs). This involves a protein complex that includes in plants the two similar proteins, SPO11-1 and SPO11-2. We analysed the sequences of SPO11-2 in hexaploid bread wheat (Triticum aestivum), as well as in its diploid and tetraploid progenitors. We investigated its role during meiosis using single, double and triple mutants. The three homoeologous SPO11-2 copies of hexaploid wheat exhibit high nucleotide and amino acid similarities with those of the diploids, tetraploids and Arabidopsis. Interestingly, however, two nucleotides deleted in exon-2 of the A copy lead to a premature stop codon and suggest that it encodes a non-functional protein. Remarkably, the mutation was absent from the diploid A-relative Triticum urartu, but present in the tetraploid Triticum dicoccoides and in different wheat cultivars indicating that the mutation occurred after the first polyploidy event and has since been conserved. We further show that triple mutants with all three copies (A, B, D) inactivated are sterile. Cytological analyses of these mutants show synapsis defects, accompanied by severe reductions in bivalent formation and numbers of DMC1 foci, thus confirming the essential role of TaSPO11-2 in meiotic recombination in wheat. In accordance with its 2-nucleotide deletion in exon-2, double mutants for which only the A copy remained are also sterile. Notwithstanding, some DMC1 foci remain visible in this mutant, suggesting a residual activity of the A copy, albeit not sufficient to restore fertility.
Complete list of metadatas

Cited literature [148 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-03006894
Contributor : Charles White <>
Submitted on : Thursday, November 19, 2020 - 10:05:13 AM
Last modification on : Friday, November 20, 2020 - 12:00:08 PM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : 2020-12-30

Please log in to resquest access to the document

Identifiers

Collections

Citation

Fatiha Benyahya, Isabelle Nadaud, Olivier da Ines, Hélène Rimbert, Charles White, et al.. SPO11.2 is essential for programmed double‐strand break formation during meiosis in bread wheat ( Triticum aestivum L.). Plant Journal, Wiley, 2020, Online ahead of print. ⟨10.1111/tpj.14903⟩. ⟨inserm-03006894⟩

Share

Metrics

Record views

40