Analysis of a two-species newt metapopulation using microsatellites
The conservation and management of species living in fragmented landscapes is often based on the metapopulation concept, but empirical evidence of how temporal and spatial metapopulation processes shape the within-species genetic diversity is so far often lacking.
Pond-breeding amphibians are particularly deme-structured organisms, and therefore well suited for addressing study questions at the level of populations.
This project aims, based on two syntopically occurring amphibian species (Triturus cristatus, the crested newt, and Triturus marmoratus, the marbled newt), to reconstruct dynamic processes in natural metapopulations based on information drawn from hypervariable genetic markers (microsatellites).
The two main axis are to (I) determine source/sink populations and to assess between-population migration rates by genetically assigning migrating individuals (and their offspring) to their population of origin, (II) infer past colonisation events, represented as population genetic bottlenecks which are detectable from microsatellite allele frequency distributions.
Approximately 25 ponds arranged in a spatial scale reflecting the migratory range of the study species (~1 km) are analysed from a study plot in western France. The differential habitat preferences of the two study species offer the opportunity to calibrate the obtained data in an ecological context.
Personnel
2001-2003 - Dr. Robert Jehle
Publications
Jehle R & Arntzen JW (2002) Review: Microsatellite markers in amphibian conservation genetics, Herpetological Journal, 12, 1-9.
Erratum: Krupa et al. (2002) Microsatellite loci in the crested newt (Triturus cristatus), and their utility in other newt taxa.Conservation Genetics, 3, 87-89.
Krupa AP, Jehle R, Dawson DA, Gentle LK, Gibbs M, Arntzen JW, Burke T (2002) Microsatellite loci in the crested newt (Triturus cristatus), and their utility in other newt taxa. Conservation Genetics, 3, 87-89.
Jehle R & Faber H (2003): Triturus-European newts. Pp. 15-23 in: Handbook of European Amphibians and Reptiles, Urodeles, Volume II. Grossenbacher K. & B Thiesmeier (Eds.). Aula, Germany (in German) (in press).
Sztatecsny M, Jehle R, Schmidt B & Arntzen JW (submitted). The abundance of praemetamorphic newts (Triturus cristatus, T. marmoratus) as a function of habitat determinants: an a priori model selection approach.
Selected background references
Arntzen JW & G Wallis (1991) Restricted gene flow in a moving hybrid zone of newts (Triturus cristatus and T. marmoratus) in western France. Evolution, 45, 805-826.
Jehle R & JW Arntzen (2000) Post-breeding migrations of newts (Triturus cristatus and T. marmoratus) with contrasting ecological requirements. Journal of Zoology (London), 251, 297-306.
Jehle R, Arntzen JW, Burke TA, Krupa A & W Hödl (2001) The annual number of breeding adults and the effective population size of syntopic newts (Triturus cristatus, T. marmoratus). Molecular Ecology, 10, 839-850.
The project is funded by a Marie Curie fellowship (EU), and conducted in close collaboration with Dr. J. W. Arntzen (Amsterdam)