5S‐IGS rDNA in wind‐pollinated trees ( Fagus L.) encapsulates 55 million years of reticulate evolution and hybrid origins of modern speciesShow others and affiliations
2021 (English)In: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313X, Vol. 109, no 4, p. 909-926Article in journal (Refereed) Published
Abstract [en]
Standard models of plant speciation assume strictly dichotomous genealogies in which a species, theancestor, is replaced by two offspring species. The reality in wind-pollinated trees with long evolutionaryhistories is more complex: species evolve from other species through isolation when genetic drift exceeds gene flow; lineage mixing can give rise to new species (hybrid taxa such as nothospecies and allopolyploids). The multi-copy, potentially multi-locus 5S rDNA is one of few gene regions conserving signal from dichotomous and reticulate evolutionary processes down to the level of intra-genomic recombination. Therefore, it can provide unique insights into the dynamic speciation processes of lineages that diversified tens of millions of years ago. Here, we provide the first high-throughput sequencing (HTS) of the 5S intergenic spacers (5S-IGS) for a lineage of wind-pollinated subtropical to temperate trees, the Fagus crenata – F.sylvatica s.l. lineage, and its distant relative F. japonica. The observed 4963 unique 5S-IGS variants reflect acomplex history of hybrid origins, lineage sorting, mixing via secondary gene flow, and intra-genomic competition between two or more paralogous-homoeologous 5S rDNA lineages. We show that modern species are genetic mosaics and represent a striking case of ongoing reticulate evolution during the past 55 million years.
Place, publisher, year, edition, pages
2021. Vol. 109, no 4, p. 909-926
Keywords [en]
Fagus, 5S rDNA, high-throughput sequencing, wind-pollination, adaptation, hybrid evolution, genetic diversity
National Category
Evolutionary Biology Other Earth Sciences
Research subject
Ecosystems and species history; The changing Earth
Identifiers
URN: urn:nbn:se:nrm:diva-4992DOI: 10.1111/tpj.15601OAI: oai:DiVA.org:nrm-4992DiVA, id: diva2:1717728
Funder
German Research Foundation (DFG), FZT 118Swedish Research Council, 2015-03986
Note
EDS and GWG gratefully acknowledge the support of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig funded by the German Research Foundation (FZT 118). The research was partially supported by MIUR (Italian Ministry for Education, University and Research), Law 232/2016, ‘Department of excellence’. Open Access Funding provided by Universita degli Studi della Tuscia within the CRUI-CARE Agreement.
2022-12-092022-12-092025-02-01Bibliographically approved