Onagraceae as a model experimental system
Greiner, Stephan , Rauwolf, Uwe , Golczyk, Hieronim , Meurer, Joerg , Herrmann, Reinhold G. .
Oenothera - Genomics tools in a model for plant evolution.
The genus Oenothera has an outstanding scientific history. More than hundred years of genetic research have made Oenothera the presumably best studied plant genus of its size. A good deal of information about taxonomy, morphology, cytogenetics, and classical genetics, as well as a rich source of experimental strains is available. Oenothera genetics displays a unique combination of non-Mendelian genetic features, like permanent translocation heterozygosity and biparental transmission of plastids. It allows the exchange of plastids between species, which often results in plastome-genome incompatibility (PGI) - a hybridization barrier according to the Dobzhansky-Muller model. In turn, PGI provides molecular access to speciation forces acting on photosynthesis. Furthermore, particular aspects of epigenetics, genome evolution, and population biology can be addressed using Oenothera as model system.So far studies in Oenothera have been mainly limited to classical genetics and cytology, while molecular approaches have been largely missing. To overcome this limitation, we have established a broad spectrum of biochemical, molecular genetic and cytogenetic methods as well as tissue culture and transformation approaches for the genus. We constructed an EST library, initiated a comparable sequencing of the mitochondria genome, sequenced the five basic plastome types, and provide first candidate loci causing PGI. Moreover, the first genetic map of bivalent forming Oenothera species has been generated assigning more than 1,700 dominant and co-dominant molecular markers to seven coupling groups. Remarkably, homologous recombination was almost completely suppressed in F2 segregants and, if it occurred at all, was restricted to the telomeric regions of the chromosomes. Unusual meiotic behaviour of chromosomes may be responsible for the massive repression of homologous recombination. Our data question the long-standing assumption that HR is primarily repressed due to reciprocal translocation of chromosome arms in ring-forming Oenothera species. Our results show that Oenothera provides an ideal model for examining hypotheses regarding the evolutionary advantages of sex, as well as of speciation.
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1 - Max Planck Institute of Molecular Plant Physiology, Department 3, Am Mühlenberg 1, Potsdam - Golm, 14476, Germany
2 - Botanisches Institut der LMU Muenchen, Department Biologie I, Menzinger Strasse 67, Munich, 80638, Germany
3 - John Paul II Catholic University of Lublin - Institute of Biotechnolog, Department of Molecular Biology, Al. Krasnicka 102, Lublin, 20-718, Poland
4 - LMU Muenchen, Department I, Chair of Botany, Grosshaderner Str. 2-4, Munich, 82152, Germany
Presentation Type: Symposium or Colloquium Presentation
Location: Lenox Room/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 3:45 PM