ARN non codants, épigénétique et stabilité génomique

Dynamique du génome


The sequencing of many different eukaryotic genomes revealed that genes represent only a small part of each genome compared with intergenic and repeated sequences (e.g. satellites, microsatellites, transposable elements). For instance, up to 45% of the human genome consists of transposable elements (TEs). Active TEs are able to replicate by inserting new copies elsewhere in the host genome, which can dramatically impact genome structure and function. However, diverse defense mechanisms (including piRNA-mediated transcriptional silencing) restrain mobilization of integrated TEs to low levels compatible with host survival. Indeed, depending on their insertion site, TEs can lead to the destruction, inactivation, or deregulation of coding genes. TEs can also affect the epigenetic landscape in the vicinity of the insertion site and the three-dimensional (3D) chromatin structure. Moreover, TE sequences are able to recruit the host transcription machinery to express their own products and promote transposition. This capacity is kept long after they have lost the ability to transpose, suggesting that TEs have significantly contributed to the evolution of transcription regulation. Indeed, selection tends to co-opt positive insertions and eliminate harmful insertions. Altogether, this gives rise to a delicate equilibrium which, when disrupted, leads to pathologies or sterility (when germ cells are concerned by transposition). 

piRNAs and PIWI proteins: 03-05 April 2024 @GENOPOLYS - MONTPELLIER, FR

PIWI proteins and PIWI-interacting RNAs (piRNAs) are essential for silencing mobile genetic elements like transposons in the animal germline and are essential for fertility in animals and humans. This meeting aims to bring the community to discuss the recent advances in the field and will cover a broad range of techniques and animal models. Speakers at this meeting will illustrate the unprecedented molecular insights into piRNA biogenesis machinery provided by structural biology investigations and explore the use of new animal model systems. While the role of piRNAs in gene regulation within the germline and in soma is now firmly established, the molecular insights are only starting to be uncovered. We will provide ample opportunities for young scientists in our community and aim to share mostly latest unpublished data. This meeting will foster new collaborations across model systems and exchange of reagents and tools.

The three following projects aim to understand these genetic conflicts and their eventual resolution at both the lab and evolutionary time scales

Project 1 : What are the impacts of TE insertions on the genome structure and function?

Project 2 : What are the transcriptional roles of piRNAs on TEs and piRNA source loci ?

Project 3 : What are the chromatin effectors of TE transcriptional repression ?


Charlotte GRIMAUD


Marion Varoqui

Margaux Gilbert

Maelys Lemoine

Gestionnaire parc binoculaires et injection


Publications de l'équipe

A Transposon Story: From TE Content to TE Dynamic Invasion of Drosophila Genomes Using the Single-Molecule Sequencing Technology from Oxford Nanopore

Mourdas Mohamed, Nguyet Thi-Minh Dang, Yuki Ogyama, Nelly Burlet, Bruno Mugat, Matthieu Boulesteix, Vincent Mérel, Philippe Veber, Judit Salces-Ortiz, Dany Severac, Alain Pélisson, Cristina Vieira, François Sabot, Marie Fablet, Séverine Chambeyron

en savoir plus

The Mi-2 nucleosome remodeler and the Rpd3 histone deacetylase are involved in piRNA-guided heterochromatin formation

Bruno Mugat, Simon Nicot, Carolina Varela-Chavez, Christophe Jourdan, Kaoru Sato, Eugenia Basyuk, François Juge, Mikiko C. Siomi, Alain Pélisson & Séverine Chambeyron

en savoir plus

The somatic piRNA pathway controls germline transposition over generations.

Barckmann B, El-Barouk M, Pélisson A, Mugat B, Li B, Franckhauser C, Fiston Lavier AS, Mirouze M, Fablet M, Chambeyron S

Transposable Element Misregulation Is Linked to the Divergence between Parental piRNA Pathways in Drosophila Hybrids

Romero-Soriano V, Modolo L, Lopez-Maestre H, Mugat B, Pessia E, Chambeyron S, Vieira C, Garcia Guerreiro MP

Piwi Is Required during Drosophila Embryogenesis to License Dual-Strand piRNA Clusters for Transposon Repression in Adult Ovaries

Akkouche, A., Mugat, B., Barckmann, B., Varela-Chavez, C., Li, B., Raffel, R., Pelisson, A., Chambeyron, S.

Identification of misexpressed genetic elements in hybrids between Drosophila-related species

Lopez-Maestre H, Carnelossi EA, Lacroix V, Burlet N, Mugat B, Chambeyron S, Carareto CM, Vieira C

Aubergine iCLIP Reveals piRNA-Dependent Decay of mRNAs Involved in Germ Cell Development in the Early Embryo

Barckmann,B., Pierson,S., Dufourt, J., Papin, C., Armenise, C., Port, F., Grentzinger, T., Chambeyron, S., Baronian, G., Desvignes, JP., Curk, T., Simonelig, M.

+ Régulation des ARNm et Développement

MicroRNA-Dependent Transcriptional Silencing of Transposable Elements in Drosophila Follicle Cells

Mugat B, Akkouche A, Serrano V, Armenise C, Li B, Brun C, Fulga TA, Van Vactor D, Pélisson A, Chambeyron S

A user-friendly chromatographic method to purify small regulatory RNAs

Grentzinger T, Armenise C, Pelisson A, Brun C, Mugat B, Chambeyron S.

Fast and Accurate Method to Purify Small Noncoding RNAs from Drosophila Ovaries

Grentzinger T, Chambeyron S.

A user-friendly chromatographic method to purify small regulatory RNAs

Grentzinger T, Armenise C, Pelisson A, Brun C, Mugat B, Chambeyron S

Epigenetics and transgenerational inheritance

Brasset E, Chambeyron S.

Maternally deposited germline piRNAs silence the tirant retrotransposon in somatic cells

Akkouche A, Grentzinger T, Fablet M, Armenise C, Burlet N, Braman V, Chambeyron S. §, Vieira C§ (co-dernier auteur)

piRNA-mediated transgenerational inheritance of an acquired trait

Grentzinger T, Armenise C, Brun C, Mugat B, Serrano V, Pelisson A, Chambeyron S.

Thèses et hdr

Étude de l'impact de la perte de répression des rétrovirus endogènes sur l'intégrité du génome chez la drosophile 16/12/2016