title: Mapping PrBn and other quantitative trait loci responsible for the control of homeologous chromosome pairing in oilseed rape (Brassica napus L.) haploids.
abstract: In allopolyploid species, fair meiosis could be challenged by homeologous chromosome pairing and is usually achieved by the action of homeologous pairing suppressor genes. Oilseed rape (Brassica napus) haploids (AC, n=19) represent an attractive model for studying the mechanisms used by allopolyploids to ensure the diploid-like meiotic pairing pattern. In oilseed rape haploids, homeologous chromosome pairing at metaphase I was found to be genetically based and controlled by a major gene, PrBn, segregating in a background of polygenic variation. In this study, we have mapped PrBn within a 10-cM interval on the C genome linkage group DY15 and shown that PrBn displays incomplete penetrance or variable expressivity. We have identified three to six minor QTL/BTL that have slight additive effects on the amount of pairing at metaphase I but do not interact with PrBn. We have also detected a number of other loci that interact epistatically, notably with PrBn. Our results support the idea that, as in other polyploid species, metaphase I homeologous pairing in oilseed rape haploids is controlled by an integrated system of several genes, which function in a complex manner.
authors.affiliation: UMR INRA-Agrocampus Rennes, Amélioration des Plantes et Biotechnologies Végétales, Le Rheu, France.
authors.forename: Zhiqian
authors.initials: Z
authors.lastname: Liu
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Adamczyk
authors.forename: Maria
authors.initials: M
authors.lastname: Manzanares-Dauleux
authors.forename: Frédérique
authors.initials: F
authors.lastname: Eber
authors.forename: Marie-Odile
authors.initials: MO
authors.lastname: Lucas
authors.forename: Régine
authors.initials: R
authors.lastname: Delourme
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Chèvre
authors.forename: Eric
authors.initials: E
authors.lastname: Jenczewski
mesh_terms: D029688:Brassica napus / Q000235:genetics*; D023902:Chromosome Pairing; D032461:Chromosomes, Plant; D005819:Genetic Markers; D006238:Haploidy; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D020161:Physical Chromosome Mapping; D011110:Polymorphism, Genetic; D040641:Quantitative Trait Loci
chemical_list: D005819:Genetic Markers