Publications by authors named "Marie Gilet"
Meiotic recombination is a key biological process in plant evolution and breeding, as it generates genetic diversity in each generation through the formation of crossovers (COs). However, due to their importance in genome stability, COs are highly regulated in frequency and distribution. We previously demonstrated that this strict regulation of COs can be modified, both in terms of CO frequency and distribution, in allotriploid Brassica hybrids (2n = 3x = 29; AAC) resulting from a cross between Brassica napus (2n = 4x = 38; AACC) and Brassica rapa (2n = 2x = 20; AA).
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- Meiosis drives genetic diversity in sexual organisms, but recombination is tightly regulated, mostly occurring in areas with low DNA methylation.
- Researchers studied two Brassica napus hybrids to identify large regions lacking recombination and explored the role of DNA methylation and structural variations in this absence.
- Findings suggest that hypermethylated or inverted regions can hinder recombination and may affect important agronomic traits, highlighting the need for breeders to consider these factors when combining beneficial alleles in crop varieties.
Meiotic recombination is the main tool used by breeders to generate biodiversity, allowing genetic reshuffling at each generation. It enables the accumulation of favorable alleles while purging deleterious mutations. However, this mechanism is highly regulated with the formation of one to rarely more than three crossovers, which are not randomly distributed.
View Article and Find Full Text PDFSeveral plastid macromolecular protein complexes are encoded by both nuclear and plastid genes. Therefore, cytonuclear interactions are held in place to prevent genomic conflicts that may lead to incompatibilities. Allopolyploidy resulting from hybridization and genome doubling of two divergent species can disrupt these fine-tuned interactions, as newly formed allopolyploid species confront biparental nuclear chromosomes with a uniparentally inherited plastid genome.
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- * Researchers created advanced hybrids by cross-pollinating oilseed rape with wild radish and analyzed the genomic integration of oilseed rape regions in the hybrids over generations.
- * Results showed that certain genomic regions of oilseed rape are more susceptible to being incorporated into the wild radish’s genome and this gene transfer could affect plant traits like height and seed production, suggesting that transgene insertion should consider gene stability to prevent unwanted gene flow.
Article Synopsis
- Meiotic recombination through crossovers (COs) is crucial for genetic diversity, but typically occurs in a limited and uneven manner on chromosomes.
- Research indicates that using allotriploid hybrids from Brassica species can disrupt these patterns, leading to a significant increase in COs—1.7 to 3.4 times more than in diploids.
- This increase results in altered recombination landscapes and decreased CO interference, particularly noticeable in male allotriploid hybrids, which could greatly benefit geneticists and plant breeders by enhancing genetic diversity in Brassica species.
Allopolyploidy, which results from the merger and duplication of two divergent genomes, has played a major role in the evolution and diversification of flowering plants. The genomic changes that occur in resynthesized or natural neopolyploids have been extensively studied, but little is known about the effects of the reproductive mode in the initial generations that may precede its successful establishment. To truly reflect the early generations of a nascent polyploid, two resynthesized allotetraploid populations were obtained for the first time by open pollination.
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- Allopolyploid species' genomes change over time, but the long-term effects on the relationship between the original genomes are still unclear.
- The study extracted the diploid AA component from Brassica napus, showing that only one method was successful and the resulting plants had less of the expected A subgenome.
- The research suggests that during coevolution over about 7,500 years, subgenome interdependency can arise due to structural changes, with some gene losses compensated by genes from related species.