Ce qui se passe ces derniers jours à l’université Paris-Saclay mérite l’attention de toutes les universités et de tou·tes les universitaires. On peut, en effet, le voir comme un épisode de cristallisa...

Recombination is advantageous over the long-term, as it allows efficient selection and purging deleterious mutations. Nevertheless, recombination suppression has repeatedly evolved in sex chromosomes and mating-type chromosomes. The evolutionary causes for recombination suppression and the proximal mechanisms preventing crossing overs are still poorly understood. Several hypotheses have recently been suggested based on theoretical models, and in particular, that divergence could accumulate neutrally around a sex-determining region and reduce recombination rates, a self-reinforcing process that could foster progressive extension of recombination suppression. The ascomycete fungus Podospora anserina is an excellent model for investigating these questions. A 0.8 Mb region around the mating-type locus is non-recombining, despite being collinear between the two mating types. This fungus is mostly selfing, so that strains are highly homozygous, except in the non-recombining region around the mating-type locus that displays differentiation between mating types. Here, we generated a mutant to test the hypothesis that sequence divergence alone is responsible for recombination cessation. We replaced the mat- idiomorph by the sequence of the mat+ idiomorph, to obtain a strain that is sexually compatible with the mat-reference strain and isogenic to this strain in the MAT-proximal region. Crosses showed that recombination was still suppressed in the MAT-proximal region in the mutant strains, indicating that other proximal mechanisms than inversions or mere sequence divergence are responsible for recombination suppression in this fungus. This finding suggests that selective mechanisms likely acted for suppressing recombination, as the neutral model does not seem to hold, at least in this fungus. ### Competing Interest Statement The authors have declared no competing interest.

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Créé en 2018, le Baromètre français de la Science Ouverte mesure chaque année l’évolution de l’accès ouvert aux publications scientifiques en France. Développé par le ministère de l’Enseignement supér...

Lors de cette vidéo, les élèves ingénieurs de CentraleSupélec de troisième année ont préparer un outil de vulgarisation scientifique sur le sujet de recherche de Pietro FERREIRA, Maître de Conférences HDR au GeePs, UMR 8507. Cette activité pédagogique fait partie de la « Semaine Communication et Recherche Durable. #engineering #mediationscientifique #electronics #iot_centralesupelec #edgeai #lowpower #research #educational #universiteparissaclay #centralesupélec For more information of my work, you can follow me on https://twitter.com/DrPi314159265 https://www.linkedin.com/in/pietro-maris-ferreira/ https://www.twitch.tv/drpiblacksmith #microelectronics #research #universiteparissaclay #centralesupélec #AIedge #lowpower #engineering #geeps