PuSH - Publication Server of Helmholtz Zentrum München

Zhang, M.* ; Castellani, M.* ; Steckenborn, S.* ; Majka, M.* ; Tsipas, G.* ; Nascimento, T.* ; Neumann, U.* ; Thangavel, G.* ; Robledillo, L.A.* ; Lux, T. ; Deberon, L.* ; Pfordt, U.* ; Campoy, J.A.* ; Vijayan, A.* ; Timmers, T.* ; Sargheini, N.* ; Marek, M.* ; Sun, H.* ; Hofstatter, P.G.* ; Hüettel, B.* ; Dreißig, S.* ; Mayer, K.F.X. ; Figueiredo, D.D.* ; Vanzela, A.L.L.* ; Schneeberger, K.* ; Marques, A.*

Sex without crossovers mimics clonal reproduction in Rhynchospora tenuis.

Nature, DOI: 10.1038/s41586-026-11057-7 (2026)
Publ. Version/Full Text Research data DOI PMC
Open Access Hybrid
Creative Commons Lizenzvertrag
Meiotic recombination ensures accurate chromosome segregation and promotes genetic diversity by generating crossovers between homologous chromosomes1. Although essential in most sexually reproducing organisms, recombination is variably regulated and can be absent in some lineages, a condition known as achiasmy2. However, obligate achiasmy in both sexes of a sexual species has not been documented. Here we investigate Rhynchospora tenuis, a flowering plant with the lowest known chromosome number and inverted meiosis3. Combining genomics with molecular experiments, we show that R. tenuis undergoes obligate, genome-wide achiasmy in both male and female meiosis. Despite normal early meiotic axis formation, synapsis fails, crossovers are undetectable cytologically and genetically, and univalents persist at metaphase I. Haplotype-specific accumulation of transposable elements generates segregation distortion favouring the transmission of larger, repeat-rich chromosomes. Sexual reproduction is nevertheless retained: fertilization yields viable seeds only when translocation-compatible gametes meet, indicating strong post-meiotic selection against incompatible homozygous combinations. As a result, all surviving offspring are genetically identical, effectively maintaining heterozygosity by sexual reproduction with parental genotype restitution mimicking clonal reproduction. We propose that recombination loss, a low chromosome number, inverted meiosis and selection for compatible gamete combinations together enable faithful segregation and clonal-like inheritance despite sexual reproduction. These findings blur the boundary between sex and clonality, linking genome architecture, recombination loss and transmission bias.
Altmetric
Additional Metrics?
[➜Log in]
Edit extra informations Login
Publication type Article: Journal article
Document type Scientific Article
Keywords Meiosis ; Synapsis ; Sexual Reproduction ; Obligate ; Homologous Chromosome ; Loss Of Heterozygosity ; Genetic Recombination ; Chromosome ; Asexual Reproduction ; Meiotic Drive; Chromosome Synapsis; Protein; Chromatin; Arabidopsis; Consequences; Inheritance; Evolution; Alignment; Meiosis; Server
ISSN (print) / ISBN 0028-0836
e-ISSN 1476-4687
Journal Nature
Publisher Nature Publishing Group
Publishing Place London
Reviewing status Peer reviewed
Institute(s) Research Unit Plant Genome and Systems Biology (PGSB)
Grants European Research Council (ERC)
Marie Curie Actions (MSCA)
European Union
Alexander von Humboldt Foundation
European Union (European Research Council)
DFG
German Research Foundation (DFG)
Max Planck Society