People
Lexer, Christian
| Job Title | Population Geneticist |
|---|---|
| Department | Jodrell |
| Section | Genetics |
| Science Teams |
Malpighiales Monocots II: Commelinids Large-Scale Syntheses |
| Joined Kew | 2003 |
| Foreign Language(s) | German (mother tongue), Portuguese (basic) |
Qualifications & Appointments
MSc, Univ. Salzburg
PhD, Univ. Agricultural Sciences, Vienna
Subject Editor & Associate Editor, Molecular Ecology
Editorial Board, Heredity
Decision Editor, Annals of Botany
Role
Plant conservation genetics, ecological genetics of plant adaptation and speciation.
Research is focused on two main themes. First the molecular marker-based conservation genetics of plant species and species groups identified as being central to Kew’s science, including conservation work with colleagues in the Jodrell Laboratory and Herbarium. Support for this work is given by advising/co-supervising colleagues and students in the lab and by regularly taking the lead-role in statistical genetic data analysis and interpretation. The primary aim in this context is to maximize the amount of science- and conservation-related genetic information that colleagues and students are able to extract from their data, and to promote the use of the best possible and most reliable molecular and computational tools for this purpose. Recent work in this context has addressed a diverse set of taxa, e.g. Orchis spp. and Cypripedium spp. (Orchidaceae), Medicago spp. (Leguminosae), Bencomia spp. (Rosaceae), Alcantarea spp. (Bromeliaceae), and Howea spp. (Arecaceae). The second main research theme revolves around the origin of species and novel phenotypes within species and uses methodologies of ecological genetics and population genomics to address these questions. This work is focused on model systems with well developed molecular phylogenies and existing genomic resources, such as Populus (poplars/aspens/cottonwoods), Helianthus (sunflowers), or members of the Bromeliaceae and Orchidaceae. In Populus, the activities of an international genome consortium include using genomic tools and natural hybrid zones (Populus alba × P. tremula) for studying components of barriers to gene flow that respond to natural selection. It is expected that this work will yield valuable insights into the genetic basis of habitat adaptation in this ecologically and economically important tree genus. It also holds great promise for identifying conserved nuclear genetic markers for resolving relationships among related groups of Malpighiales. In addition time is given to peer review for a wide range of journals and funding bodies. Co-organizer of ‘Kew Journal Club’ and ‘Molecular Systematics Seminars’ at Kew.
Projects
Introgression of Abiotic Stress Response Genes across Hybrid Zones in Populus
Morphometrics and Phylogeography of Anthurium and Monstera (Araceae) in NE Brazil
Sympatric Speciation in Palms: Howea on Lord Howe Island
Selected Publications 2001-2005
Widmer, A. & Lexer, C. (2001). Glacial refugia: sanctuaries for allelic richness, but not for gene diversity. Trends in Ecology and Evolution 16: 267-269.
Lexer, C., Welch, M.E., Durphy, J.L. & Rieseberg, L.H. (2003). Natural selection for salt tolerance quantitative trait loci (QTLs): Implications for the origin of Helianthus paradoxus, a diploid hybrid species. Molecular Ecology 12:1225-1235.
Rieseberg, L.H., Raymond, O., Rosenthal, D.M., Lai, Z., Livingstone, K., Nakazato, T., Durphy, J.L., Schwarzbach, A.E., Donovan, L.A. & Lexer, C. (2003). Major ecological transitions in wild sunflowers facilitated by hybridization. Science 301:1211-1216.
Lexer, C., Fay, M.F., Joseph, J.A., Heinze, B. & Sorin, M-S. (2005). Barrier to gene flow between two ecologically divergent Populus species, Populus alba (white poplar) and P. tremula (European aspen): the role of ecology and life history in gene introgression. Molecular Ecology 14: 1045-1057.
Lexer, C., Rosenthal, D.M., Raymond, O., Donovan, L.A. & Rieseberg, L.H. (2005). The genetics of species differences in the wild annual sunflowers, Helianthus annuus and H. petiolaris. Genetics 169: 2225-2239.
Selected Publications pre-2001
Steinkellner, H., Fluch, S., Turetschek, E., Lexer, C., Streiff, R., Kremer, A., Burg, K. & Glössl, J. (1997). Identification and characterization of (GA/CT)n -microsatellite loci from Quercus petraea. Plant Molecular Biology 33: 1093-1096.
Steinkellner, H., Lexer, C., Turetsche, E. & Glössl, J. (1997). Conservation of (GA)n microsatellite loci between Quercus species. Molecular Ecology 6: 1189-1194.
Lexer, C., Heinze, B., Steinkellner, H., Kampfer, S., Ziegenhagen, B. & Glössl, J. (1999). Microsatellite analysis of maternal half-sib families of Quercus robur, pedunculate oak: detection of seed contaminations and inference of the seed parents from the offspring. Theoretical and Applied Genetics 99: 185-191.
Streiff, R., Ducousso, A., Lexer, C., Steinkellner, H., Glössl, J. & Kremer, A. (1999). Pollen dispersal inferred from paternity analysis in a mixed oak stand of Quercus robur and Quercus petraea (Matt.) Liebl. Molecular Ecology 8: 831-841.
Lexer, C., Heinze, B., Gerber, S., Macalka-Kampfer, S., Steinkellner, H., Kremer A. & Glössl, J. (2000). Microsatellite analysis of maternal half-sib families of Quercus robur, pedunculate oak (II): inferring the number of pollen donors from the offspring. Theoretical and Applied Genetics 100: 858-865.