Seminaire de Maximilien ADAM @cbgpmontpellier.bsky.social

▶️Interactions among hosts, #microorganisms and #parasitoids

📅Vendredi 23 mai à 12h

▶️ www.ideev.universite-paris-saclay.fr/seminaires/2...

@inrae-france.bsky.social #ideev #semideev

Début du projet Butterfly de Horizon Europe!
www.egce.universite-paris-saclay.fr?p=20556
#IDEEV

Les personnels de @ideevl.bsky.social mobilisés pour l'évènement Stand Up For Science le 7 mars 2025.

#standupforscience #insolidarity #ideev

Défendons les sciences Défendons les sciences Les sciences et les humanités, la liberté académique et l’université sont des piliers d’une société démocratique (1). Dans de nombreux pays, dont la France, la démarche scientif...

Défendons les sciences !

Les personnels et les étudiant.e.s de #IDEEV déclarent leur inquiétude face à la remise en cause de la science et appellent à la mobilisation pour la journée du 7 mars

@standupforscifr.bsky.social #standupforscience #ideev

▶️ En savoir plus : tinyurl.com/mrzy2cuc

Genetic differentiation in the MAT-proximal region is not sufficient for suppressing recombination in Podospora anserina 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.

Happy to see our last preprint online! We show that a mysterious recombination inhibition persists even with identical sequences on both mating-type chromosomes in our favorite fungus #Podospora anserina.

www.biorxiv.org/content/10.1...

#universiteparissaclay #i2bc #ideev #cnrs