Research
Studies in plant meiosis have made and continue to make an important contribution to fundamental research aimed at the understanding of this complex division. Indeed plants appear to have relaxed meiotic checkpoints in comparison with other species. This makes plants powerful tools to analyze meiotic progression and allows plant breeding for the generation of new traits of agronomic, environmental and economic importance. Recent studies in the model species Arabidopsis thaliana have substantially improved our understanding of how meiotic recombination is controlled in plants. It allows molecular approaches to be combined with new developments in cytological methods. Nevertheless, in Arabidopsis thaliana, as in other model organisms, there are conspicuous gaps in the understanding of the mechanisms underlying in the first meiotic prophase: pairing, synapsis and recombination and the relationships between them. Our research in the last years has been focused to contribute in some way to fill some of these gaps, especially those related to meiotic recombination.
The factors that control meiotic recombination have the potential to provide the breeder with the means to make fuller use of the genetic variability that is available in crop species. For example, in cereal crops, the distribution of reciprocal genetic exchanges (crossovers, COs) is predisposed to the ends of the chromosomes, such that ~30-50% of the genes rarely recombine. Thus, the frequency and distribution of meiotic COs is a major constraint to future crop improvement.
In order to improve our knowledge on the effects of genes involved in the recombination process of Angiosperms we use the plant model species Arabidopsis thaliana, but also crop species such as tetraploid and hexaploid wheat. For this purpose, we have focused our research in the study of some of the cis and trans factors that affect homologous recombination (HR). The cis factors are related to the DNA itself or to the chromatin and the trans factors correspond to the machinery that regulates or catalyzes the HR reaction. Among the former ones, we have studied the effects of the protein complex CAF-1, which is involved in chromatin organization during DNA replication and DNA repair. We have also determined the role of inner nuclear envelope proteins (e.g. SUN proteins) that are part of complexes linking cytoskeletal elements with the nucleoskeleton, connecting telomeres to the force-generating mechanism in the cytoplasm. Among the trans factors, we have analyzed the role of the recombinase RAD51, one of the most important proteins in the HR process. Currently, we are also involved in a project on the role of meiotic recombination in auto- (Arabidopsis) and allopolypoid (wheat, Triticum turgidum) landscapes.
Media resources
Wheat field picture
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