Skip to Main content Skip to Navigation
Journal articles

Homeologous recombination plays a major role in chromosome rearrangements that occur during meiosis of Brassica napus haploids

Abstract : Chromosomal rearrangements have played a major role in the evolution and speciation of plants and animals and can be triggered by recombination between distinct but related regions. Brassica napus (AACC; 2n=38) is a recent allopolyploid species resulting from multiple independent hybridization events between ancestors of the modern diploid B. oleracea (CC) and B. rapa (AA), whose genomes are widely replicated. In this paper, we use molecular markers spanning 4 linkage groups to genotype progenies of haploid B. napus (AC, n=19) and analyze the extent to which chromosomal rearrangements originate from homeologous exchanges during meiosis. We show that duplications and losses of chromosomal regions frequently occur during meiosis of B. napus haploids and provide genetic evidence that at least 51 to 65% of them are due to recombination between regions of primary homeology. This represents a 10 to 100 fold increase compared to the frequency of homeologous recombination measured in euploid lines. We also observed that an average of 0.7 and 0.8 autosyndetic bivalents form at Metaphase I within C or A chromosomes, respectively, which indicates that recombination might also occur between regions showing intragenomic homology (paralogues). These results are discussed in the context of genome evolution of B. napus.
Document type :
Journal articles
Complete list of metadata

https://hal.inrae.fr/hal-02668271
Contributor : Migration Prodinra <>
Submitted on : Sunday, May 31, 2020 - 12:27:52 PM
Last modification on : Tuesday, September 14, 2021 - 3:20:02 PM

Links full text

Identifiers

Citation

Stephane Nicolas, Guillaume Le Mignon, Frederique Eber, Olivier Coriton, Hervé Monod, et al.. Homeologous recombination plays a major role in chromosome rearrangements that occur during meiosis of Brassica napus haploids. Genetics, Genetics Society of America, 2007, 175 (2), pp.487-503. ⟨10.1534/genetics.106.062968⟩. ⟨hal-02668271⟩

Share

Metrics

Record views

54