raphmercier.bsky.social

raphmercier.bsky.social

@raphmercier.bsky.social

#Meiosis4ever. #ChromosomeBiology. Max Planck for Plant Breeding Research.

1.5K followers288 following71 posts

raphmercier.bsky.social reposted

Polina Novikova
@pnovik.bsky.social

I am happy to present our work @liverworks.bsky.social @robinburns.bsky.social @alisondawnscott.bsky.social on centromeric repeat turnovers, of which we counted three in the Arabidopsis genus:

biorxiv.orgThe Nature of Centromeric Repeat Turnovers in the genus ArabidopsisCentromeres are critical for accurate segregation of chromosomes and are often composed of megabases of tandemly arranged satellite repeats. Yet, despite their conserved function, the DNA sequence of ...

raphmercier.bsky.social reposted

André Marques
@amarques.bsky.social

Out today in Nature: sex without crossovers. Rhynchospora tenuis makes pollen, fertilises and sets seed, yet 0 crossovers in 10,997 pollen nuclei. Chromosome drive and ~87% seed abortion rebuild the mother's genotype, so the offspring are clones. doi.org/10.1038/s415...

André Marques@amarques.bsky.social

A new extreme of meiotic evolution: ✔️ 𝗻𝗼 crossovers ✔️ 𝗻𝗼 gene conversion ✔️ 𝗻𝗼𝗿𝗺𝗮𝗹 meiosis & fertility Sex mimics clonality without becoming asexual, in the holocentric multicellular eukaryote 𝘙𝘩𝘺𝘯𝘤𝘩𝘰𝘴𝘱𝘰𝘳𝘢 𝘵𝘦𝘯𝘶𝘪𝘴. more about it: www.biorxiv.org/content/10.6...

raphmercier.bsky.social reposted

Max Planck Institute for Plant Breeding Research
@mpipz.bsky.social

📣📣Paper Alert! New paper @nature.com from the Marques group @amarques.bsky.social and colleagues on Rhynchospora tenuis - 🌿a plant that reproduces sexually but has completely lost the reshuffling of DNA🧬 Congratulations! 👏 🥳 Read more👉 www.mpipz.mpg.de/pr-marques-2... www.nature.com/articles/s41...

nature.comSex without crossovers mimics clonal reproduction in Rhynchospora tenuis - NatureRhynchospora tenuis undergoes obligate, genome-wide achiasmy in both male and female meiosis.
raphmercier.bsky.social
@raphmercier.bsky.social

and guess what, some did! The cohesion regulators CTF18 and SGO2, and the deSUMOylase SPF2 actively limit centromere proximal crossover. Their mutation allows both the formation of crossover where they were completely absent in the wild-type, and enhance their frequency where they were rare!

raphmercier.bsky.social
@raphmercier.bsky.social

The identification of the very conserved CTF18, SGO2 and SPF2 as suppressors of centromere-proximal crossovers highlights the importance of cohesin turnover in this process and opens up new possibilities for plant breeding. rdcu.be/fvHfe

rdcu.beThe deSUMOylase SPF2 and the cohesin regulators SGO2 and CTF18 suppress crossovers near centromeresNature Plants - Gamboa et al. identified three proteins that restrict meiotic crossovers near centromeres. This finding suggests that cohesion regulation plays a role in this suppression and...
raphmercier.bsky.social
@raphmercier.bsky.social

Meiotic crossover shuffle genetic information. But, they are non-uniformly distributed along chromosomes and almost universally suppressed in centromere-proximal regions. How crossover are prevented next to centromere is unclear.

raphmercier.bsky.social reposted

François Parcy
@flowerwhatelse.bsky.social

On mange des OGM tous les jours depuis plusieurs décennies (les plantes obtenues par mutagénèse chimique ou radiative) et ça ne pose aucun problème

POLLINIS@pollinis.org

Il est temps que les institutions européennes défendent l'intérêt général et le droit des consommateurs à savoir ce qu'ils mangent et à choisir librement. #NGT #NouveauxOGM

raphmercier.bsky.social reposted

Chloe Girard, PhD
@chloegirard.bsky.social

This is the work of a tremendous PhD student, Benoit Madec, who did everything in this study (genetics, molecular biology, all the bioinformatics analyses) He defended his PhD on Monday and is now Dr Madec! I am very proud of him and all the work he has accomplished!

Chloe Girard, PhD@chloegirard.bsky.social

🚨 First pre-print from my team !! TL;DR: presence of polymorphism (sequence differences between the homologous chromosomes) can *increase* the local rate of recombination in Arabidopsis thaliana, turning cold regions of the genome hot (purple v. grey) !

raphmercier.bsky.social reposted

Chloe Girard, PhD
@chloegirard.bsky.social

🚨 First pre-print from my team !! TL;DR: presence of polymorphism (sequence differences between the homologous chromosomes) can *increase* the local rate of recombination in Arabidopsis thaliana, turning cold regions of the genome hot (purple v. grey) !

raphmercier.bsky.social reposted

Maddy Seale
@maddyseale.bsky.social

Out First Release in @science.org this week: A large scale analysis of the epigenetics of transposable elements in Arabidopsis shows transgenerational stability www.science.org/doi/10.1126/... #PlantScience

science.orgTransposable elements are vectors of recurrent transgenerational epigenetic inheritanceDNA methylation loss at transposable elements (TEs) can affect neighboring genes and be epigenetically inherited in plants, yet the determinants and significance of this additional system of inheritan...

raphmercier.bsky.social reposted

wcrismani.bsky.social
@wcrismani.bsky.social

I feel incredibly privileged to share this study on Fanconi anaemia, based on a small but important cohort. This work describes the genetics and clinical outcomes of patients in Australia and New Zealand with a diagnosis of FA. www.sciencedirect.com/science/arti...

sciencedirect.comClinical and genetic spectrum of Fanconi anemia in Australia and New ZealandFanconi anemia (FA) is a rare genetic condition that predisposes to progressive bone marrow failure, a specific spectrum of malignancies, including he…

raphmercier.bsky.social reposted

Zwicker Group
@zwickergroup.bsky.social

This is a great opportunity to start an independent group in one of the best research environments you could think of!

Max-Planck-Gesellschaft@maxplanck.de

Springboard for an international scientific career! 🧬🧪🔭⚛️🧠🌱 Call for #MaxPlanckResearchGroups launched; applications are possible until October 14, 2025 www.mpg.de/max-planck-r... #ScienceCareer

raphmercier.bsky.social reposted

Schnittger Lab
@schnittger-lab.bsky.social

Replying to @schnittger-lab.bsky.social

Six more years—plus a lot of blood, sweat, and tears—later, we are thrilled to finally share it: a cytological framework of female meiosis in Arabidopsis! www.biorxiv.org/content/10.1...

biorxiv.orgA cytological framework of female meiosis in ArabidopsisFemale and male meiosis often differ in many aspects, such as their duration and the frequency as well as the positioning of crossovers. However, studying female meiosis is often very challenging and ...