title: Aberrant genome size and instability of Phytophthora ramorum oospore progenies.
abstract: The functionality of the sexual cycle in the heterothallic pathogen Phytophthora ramorum, causal agent of Sudden Oak Death, has recently been demonstrated. Sexual reproduction could create genotypic variation and increase the pathogen's ability to adapt to other host plants or changing environments. Genetic characterization using co-dominant microsatellite markers and flow cytometry of single-oospore progeny of crosses between a European A1 isolate and North American or European A2 isolates revealed a considerable number of non-Mendelian inheritance events. This includes inheritance of more than two alleles at a locus and non-inheritance of alleles from one parent at another locus. The progenies were mitotically unstable: zoospore and hyphal tip derivatives of the progenies showed genotypic rearrangements and phenotypic variation. Flow cytometry confirmed variation and instability in DNA content of the single-oospore progenies. This indicates that single-oospore progenies not only display aberrant genomic and phenotypic variation due to meiotic irregularities, but also extra variation as a result of post-meiotic genomic rearrangements.
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Plant Sciences Unit, Crop Protection, Burg. Van Gansberghelaan 96 Bus 2, 9820 Merelbeke, Belgium.
authors.forename: Annelies
authors.initials: A
authors.lastname: Vercauteren
authors.forename: Xavier
authors.initials: X
authors.lastname: Boutet
authors.forename: Liesbet
authors.initials: L
authors.lastname: D'hondt
authors.forename: Erik
authors.initials: E
authors.lastname: Van Bockstaele
authors.forename: Martine
authors.initials: M
authors.lastname: Maes
authors.forename: Leen
authors.initials: L
authors.lastname: Leus
authors.forename: Anne
authors.initials: A
authors.lastname: Chandelier
authors.forename: Kurt
authors.initials: K
authors.lastname: Heungens
mesh_terms: D005434:Flow Cytometry; D016681:Genome, Fungal; D018895:Microsatellite Repeats; D010838:Phytophthora / Q000166:cytology / Q000235:genetics* / Q000254:growth & development*; D013172:Spores, Fungal / Q000166:cytology / Q000235:genetics / Q000254:growth & development