Projekt

Zurück zur Übersicht

Intraspecific consequences of a porous species boundary in European Populus

Gesuchsteller/in Lexer Christian
Nummer 127059
Förderungsinstrument Projektförderung (Abt. I-III)
Forschungseinrichtung Unité d'Ecologie et Evolution Département de Biologie Université de Fribourg
Hochschule Universität Freiburg - FR
Hauptdisziplin Botanik
Beginn/Ende 01.02.2010 - 31.08.2013
Bewilligter Betrag 529'215.00
Alle Daten anzeigen

Alle Disziplinen (3)

Disziplin
Botanik
Genetik
Oekologie

Keywords (13)

Evolutionary genomics; Populus; Adaptive introgression; Reproductive isolation; Ecological divergence; Selective sweep; Local adaptation; Porous genome; speciation; selection; gene flow; recombination; hybrid zone

Lay Summary (Englisch)

Lead
Lay summary
The genetics of speciation is one of the current 'hot topics' of evolutionary biology. An important recent finding of the genomics era was that reproductive barriers between species often do not conform to the idea of 'whole genome isolation'. Rather, in many organismal groups (e.g. birds, fishes, insects, and plants), divergent populations or species exhibit 'porous' genomes. This means that some genes or genome regions are protected from exchange between diverging forms already early on during the speciation process, whereas other genes can move back and forth between divergent populations and species for hundreds or thousands of generations. Questions of great current interest revolve around the functional role and nature of 'speciation genes', i.e. genes directly involved in the speciation process, and the ecological impact of those genes that manage to move across species' boundaries. In this project, we will address these topics for Populus alba and P. tremula, two hybridizing, ecologically divergent forest trees with wide overlapping geographic ranges across Europe. These two forest trees were chosen because a complete genomic sequence is available for Populus, and because of the great ecological importance and potential economic value ('bio fuels') that poplar trees have in many parts of the world.The project will be implemented in three steps. First, we will gather DNA sequence information for a large number of functionally important genes in these two species, using 'next generation' sequencing technologies. Next, we will study the dynamics of these genes in natural populations including several 'hybrid zones', i.e. localities where these species meet, mate, and cross. Finally, we will evaluate patterns of diversity within and immediately adjacent to the most interesting genes. This will allow us to see how natural selection affects the surrounding genome, i.e. how fine-grained or 'porous' the species barrier is.The evolutionary genomics of speciation and species boundaries represents one of the most hotly debated topics in biology. Through its focus on two native European forest trees, the project will contribute significantly to our understanding of the origin and evolution of functionally relevant biodiversity in keystone or foundation species in terrestrial habitats. Information about DNA variants in ecologically important genes and their natural transfer across species barriers will be accessible by breeders, forest management and conservation bodies such as those collaborating on this project, thus the practical relevance of the results is certain. See also: http://www.unifr.ch/biol/ecology/lexer/research.htm
Direktlink auf Lay Summary Letzte Aktualisierung: 21.02.2013

Verantw. Gesuchsteller/in und weitere Gesuchstellende

Mitarbeitende

Publikationen

Publikation
Admixture mapping of quantitative traits in Populus hybrid zones: power and limitations
Lindtke D, Gonzalez-Martınez SC, Macaya-Sanz D, Lexer C (2013), Admixture mapping of quantitative traits in Populus hybrid zones: power and limitations, in Heredity, advance online, 1.
Genomic scan for single nucleotide polymorphisms reveals patterns of divergence and gene flow between ecologically divergent species
Stoelting Kai N., Nipper Rick, Lindtke Dorothea, Caseys Celine, Waeber Stephan, Castiglione Stefano, Lexer Christian (2013), Genomic scan for single nucleotide polymorphisms reveals patterns of divergence and gene flow between ecologically divergent species, in MOLECULAR ECOLOGY, 22(3), 842-855.
Effects of interspecific recombination on functional traits in trees revealed by metabolomics and genotyping-by-resequencing
Caseys Celine, Glauser Gaetan, Stoelting Kai N., Christe Camille, Albrectsen Benedicte R., Lexer Christian (2012), Effects of interspecific recombination on functional traits in trees revealed by metabolomics and genotyping-by-resequencing, in PLANT ECOLOGY & DIVERSITY, 5(4), 457-471.
Recombinant hybrids retain heterozygosity at many loci: new insights into the genomics of reproductive isolation in Populus
Lindtke Dorothea, Buerkle C. A., Barbara Thelma, Heinze Berthold, Castiglione Stefano, Bartha Denes, Lexer Christian (2012), Recombinant hybrids retain heterozygosity at many loci: new insights into the genomics of reproductive isolation in Populus, in MOLECULAR ECOLOGY, 21(20), 5042-5058.
Whole genome sequencing (WGS) meets biogeography and shows that genomic selection in forest trees is feasible
Lexer Christian, Stoelting Kai N. (2012), Whole genome sequencing (WGS) meets biogeography and shows that genomic selection in forest trees is feasible, in NEW PHYTOLOGIST, 196(3), 652-654.
Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species
Macaya-Sanz D, Suter L, Joseph J, Barbara T, Alba N, Gonzalez-Martinez SC, Widmer A, Lexer C (2011), Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species, in HEREDITY, 107(5), 478-486.
Tracing the recombination and colonization history of hybrid species in space and time
Lexer C, Stolting KN (2011), Tracing the recombination and colonization history of hybrid species in space and time, in MOLECULAR ECOLOGY, 20(18), 3701-3704.
Conservation Genomics
Hidalgo E Gonzalez-Martinez SC Lexer C Heinze B (2010), Conservation Genomics, in Jansson S Bhalerao R Groover A (ed.), Springer, Heidelberg & New York, 349-368.
Genomic Admixture Analysis in European Populus spp. Reveals Unexpected Patterns of Reproductive Isolation and Mating
Lexer C, Joseph JA, van Loo M, Barbara T, Heinze B, Bartha D, Castiglione S, Fay MF, Buerkle CA (2010), Genomic Admixture Analysis in European Populus spp. Reveals Unexpected Patterns of Reproductive Isolation and Mating, in GENETICS, 186(2), 699-699.
Polymorphism of postmating reproductive isolation within plant species
Scopece G, Lexer C, Widmer A, Cozzolino S (2010), Polymorphism of postmating reproductive isolation within plant species, in TAXON, 59(5), 1367-1374.
‘Next generation’ biogeography: towards understanding the drivers of species diversification and persistence
Lexer C, Mangili S, Bossolini E, Forest F, Stolting KN, Pearman PB, Zimmermann NE, Salamin N, ‘Next generation’ biogeography: towards understanding the drivers of species diversification and persistence, in Journal of Biogeography.

Zusammenarbeit

Gruppe / Person Land
Formen der Zusammenarbeit
Royal Botanic Gardens, Kew Grossbritannien und Nordirland (Europa)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Publikation
- Austausch von Mitarbeitern
University of Salerno Italien (Europa)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Publikation
- Forschungsinfrastrukturen
Umea Plant Science Centre Schweden (Europa)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Publikation
- Forschungsinfrastrukturen
- Austausch von Mitarbeitern
Floragenex Vereinigte Staaten von Amerika (Nordamerika)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Publikation
- Forschungsinfrastrukturen
Functional Genomics Center Zürich Schweiz (Europa)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Forschungsinfrastrukturen
Swiss Plant Science Web - Chemical Analytical Service Schweiz (Europa)
- vertiefter/weiterführender Austausch von Ansätzen, Methoden oder Resultaten
- Publikation
- Forschungsinfrastrukturen
- Austausch von Mitarbeitern

Wissenschaftliche Veranstaltungen

Aktiver Beitrag

Titel Art des Beitrags Titel des Artikels oder Beitrages Datum Ort Beteiligte Personen
Forest Genetics 2013 Vortrag im Rahmen einer Tagung 22.07.2013 Whistler, Kanada Caseys Céline;
Plant Population Biology 2013 Vortrag im Rahmen einer Tagung 09.05.2013 Tartu, Estland Lexer Christian;
BioSyst.EU 2013 Global systematics Vortrag im Rahmen einer Tagung 18.02.2013 Vienna, Austria, Österreich Lexer Christian;
Adaptive Landscape Genetics Vortrag im Rahmen einer Tagung 07.02.2012 Neuchatel, Switzerland, Schweiz Lexer Christian;
Next Generation Plant Ecology & Evolution workshop Vortrag im Rahmen einer Tagung 18.10.2011 Edinburgh, U.K., Grossbritannien und Nordirland Lexer Christian;
Genomics of Tropical Species workshop Vortrag im Rahmen einer Tagung 22.06.2011 Xishuangbanna, China, China Lexer Christian;
Evolution 2010 conference Vortrag im Rahmen einer Tagung 25.07.2010 Portland, Oregon, USA, Vereinigte Staaten von Amerika Lexer Christian;


Selber organisiert

Titel Datum Ort
Rapid evolution during biological invasions 06.09.2012 Fribourg, Switzerland, Schweiz
Biology 2012 08.02.2012 Fribourg, Switzerland, Schweiz
Evolutionary Genomics of Adaptation 02.09.2010 Fribourg, Schweiz

Veranstaltungen zum Wissenstransfer

Aktiver Beitrag

Titel Art des Beitrags Titel des Artikels oder Beitrages Datum Ort Beteiligte Personen
Zukunftstrends der Integrativen Biodiversitätsforschung 21.11.2011 Vienna, Austria, Österreich


Kommunikation mit der Öffentlichkeit

Kommunikation Titel Medien Ort Jahr
Medienarbeit: Printmedien, Online-Medien Ice Age 4: Das Würfelspiel der Gene Presseaussendung, weiterverarbeitet und veröffentlicht von La Libertè, Tagesanzeiger, und 20 Minuten Deutschschweiz Westschweiz 2010

Auszeichnungen

Titel Jahr
Mobility grant from ProDoc 'Population Genomics' doctoral school 2013
Travel grant from ESF 'Conservation Genomics' program 2011

Verbundene Projekte

Nummer Titel Start Förderungsinstrument
134660 High density admixture mapping for assessing the impact of interspecific recombination in ecologically important species 01.12.2011 ProDoc (Forschungsmodul, FM)
149306 Coupling genomics with experiments to study divergence-with-gene-flow in trees 01.03.2014 Projektförderung (Abt. I-III)

Abstract

Reproductive barriers between species often do not conform to the idea of ‘whole genome isolation’. Rather, in many organismal groups such as birds, fishes, insects, and plants, divergent populations or species exhibit ‘porous’ genomes, implying that reproductive isolation often has a genic basis and can be studied with genetic tools. This ‘genic view’ of speciation and species evolution has driven rapid recent progress in speciation genomics, i.e. research on the mechanisms that generate and maintain biological diversity and adaptive differences in nature.A very little understood aspect of the porous genome is the full impact of porous species barriers on the evolution of functionally relevant variation within species. Predictions from theoretical models have so far been tested only in a small number of model organisms, and even there many important questions remain open. These include questions regarding the actual genetic mechanisms underlying species isolation (e.g. underdominance vs. negative epistasis), the functional role and nature of isolation genes (e.g. intrinsic or ecological), and questions regarding the genomic patterns of recombination that structure porous genomes into ‘genomic islands’ of divergence on the one hand, and into movable, introgression-prone regions on the other. We also know little to nothing about the proportion of introgressed genes that spread within the recipient species’ ranges due to positive selection.In this project I propose to address these topics for Populus alba and P. tremula, two hybridizing, ecologically divergent (flood-plain vs. upland pioneer) forest trees with wide overlapping geographic ranges across Europe. Recent and ongoing work in my lab indicates the presence of a wide range of recombinant genotypes in multiple localities where these species hybridize. This sets the stage for the present project by providing the opportunity to study a large number of well characterized genes potentially involved in species isolation and adaptive introgression. The proposed work is structured into three clearly defined steps.In the first step, we will use high-throughput sequencing of short DNA amplicons to develop molecular genetic markers (SNPs and microsatellites) in or near 250 expressed genes with known functional roles in flooding tolerance, phenology, and plant defence, the latter including clusters of pathogen resistance genes near the sex determination locus. The results will contribute to a genome-wide ‘divergence map’ for these two species and help clarify the role of the sex determining region in species isolation. In the second step, we will examine ‘genomic clines’ for each gene or gene-cluster in two hybrid zone ‘replicates’ to identify loci involved in species isolation on the one hand, and candidate loci for adaptive introgression on the other. In the same step, we will track polymorphisms in each gene in up to eight para- or allopatric populations of P. alba to determine the minimum number of introgressed genes that spread across the Western portion of the species’ range. In the third step, we will characterize top candidate loci for species isolation and adaptive introgression by analyzing full-length sequences and by assaying polymorphisms in nearby genes. This will allow us to evaluate patterns of diversity and linkage disequilibrium (LD) surrounding these non-neutral polymorphisms.The evolutionary genomics of speciation and species boundaries represents one of the most hotly debated topics in biology. Through its focus on two native European forest trees, the project will contribute significantly to our understanding of the origin and evolution of functionally relevant biodiversity in keystone or foundation species in terrestrial habitats. Information about DNA variants in ecologically important genes and their introgression across species barriers will be accessible by breeders, forest management and conservation bodies such as those collaborating on this project, thus the practical usefulness of the results is certain.
-