Project description:Bdelloid rotifers are part of the restricted circle of multicellular animals that can withstand a wide range of genotoxic stresses at any stage of their life cycle. In this study, bdelloid rotifer Adineta vaga was used as a model to decipher the molecular basis of their extreme tolerance. Proteomic analysis showed that a specific DNA ligase, different from those usually involved in DNA repair in eukaryotes, is strongly over-represented upon ionizing radiation. A phylogenetic analysis revealed its orthology to prokaryotic DNA ligase E, and its horizontal acquisition by bdelloid rotifers and plausibly other eukaryotes. The fungus Mortierella verticillata, having a single copy of this DNA Ligase E homolog, also exhibits an increased radiation tolerance with an over-expression of this DNA ligase E following X-ray exposure. We also provide evidence that A. vaga ligase E is a major contributor of DNA breaks ligation activity, which is a common step of all important DNA repair pathways. Consistently, its heterologous expression in human cell lines significantly improved their radio-tolerance. Overall, this study highlights the potential of horizontal gene transfers in eukaryotes, and their contribution to the adaptation to extreme conditions.
Project description:CSF-1R is recruited on EGR1 motifs in monocytes where it colocalizes with EGR1. To address if EGR1 required for CSF-1R recruitment on chromatin, THP-1 monocytic cell line has been deleted for EGR1 by CRISPR-Cas9 approach. 3 clones were generated by single cell cloning and CSF-1R localization on chromatin was compared to two unmodified THP-1 clones by ChIP-sequencing. Since the read number was strongly decreased in the EGR1-deleted clones, the three clones were pooled for the comparison with wild-type clones. ChIPseq of CSF-1R (Nter Antibody) in monocytes of two CMML patients (CMML2130 and CMML2609)