title: Combining two-stage testing and interval mapping strategies to detect QTL for resistance to bonamiosis in the european flat oyster Ostrea edulis.
abstract: We have identified quantitative trait loci (QTL) in the flat oyster (Ostrea edulis) for resistance to Bonamia ostreae, a parasite responsible for the dramatic reduction in the aquaculture of this species. An F(2) family from a cross between a wild oyster and an individual from a family selected for resistance to bonamiosis was cultured with wild oysters injected with the parasite, leading to 20% cumulative mortality. Selective genotyping of 92 out of a total of 550 F(2) progeny (i.e., 46 heavily infected oysters that died and 46 parasite-free oysters that survived) was performed using 20 microsatellites and 34 amplification fragment length polymorphism primer pairs. Both a two-stage testing strategy and QTL interval mapping methods were used. The two-stage detection strategy had a high power with a low rate of false positives and identified nine and six probable markers linked to genes of resistance and susceptibility, respectively. Parent-specific genetic linkage maps were built for the family, spanning ten linkage groups (n = 10) with an observed genome coverage of 69-84%. Three QTL were identified by interval mapping in the first parental map and two in the second. Good concordance was observed between the results obtained after the two-stage testing strategy and QTL mapping.
authors.affiliation: Laboratoire Génétique et Pathologie, Ifremer, Ronce-les-bains, 17390, La Tremblade, France. d.lallias@bangor.ac.uk
authors.forename: D
authors.initials: D
authors.lastname: Lallias
authors.forename: L
authors.initials: L
authors.lastname: Gomez-Raya
authors.forename: C S
authors.initials: CS
authors.lastname: Haley
authors.forename: I
authors.initials: I
authors.lastname: Arzul
authors.forename: S
authors.initials: S
authors.lastname: Heurtebise
authors.forename: A R
authors.initials: AR
authors.lastname: Beaumont
authors.forename: P
authors.initials: P
authors.lastname: Boudry
authors.forename: S
authors.initials: S
authors.lastname: Lapègue
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D041602:Haplosporida / Q000502:physiology*; D006790:Host-Parasite Interactions / Q000235:genetics*; D049895:Ostrea / Q000235:genetics* / Q000469:parasitology*; D040641:Quantitative Trait Loci; D016019:Survival Analysis