Section: New Results

Modelling the influence of karyotype on the distribution of meiotic recombination

Given the important evolutionary role of recombination, recent work has focused on understanding the dynamics of this molecular process. We analysed the variation of recombination rate among species in relation to their karyotype. Specifically, we developed a non-linear model between the total genetic and physical lengths of chromosomes. Our model incorporates important biological knowledge of the recombination process. It further allows the estimation of two main parameters of recombination: the additional recombination rate per Mb and the per-species average strength of interference. Since the model is defined on data from genetic maps, at the global level of the karyotype, it can be applied even on low-resolution data and, hence, can result in the exploration of multiple species. By analysing the variability of our models recombination parameters among species, we showed that the recombination rate and the interference strength are regulated at the Mb scale of the genomes. We found that the genome size is a strong predictor of the recombination rate, while the average physical length of chromosomes is positively correlated with the interference parameter of our model. These relations represent valuable tools for the estimation of recombination parameters even for species lacking genetic maps. This work is in submission. This work was done in collaboration with D. Mouchiroud.