Fabrice, F. | Search bioRxiv

bioRxiv2021

AAV-delivery of diacylglycerol kinase kappa achieves long-term rescue of Fmr1-KO mouse model deficits of fragile X syndrome

Fragile X syndrome (FXS) is the most frequent form of familial intellectual disability. It results from the lack of the RNA binding protein FMRP and is associated with the overactivation of signaling pathways downstream of mGluRI receptors and upstream of mRNA translation. We previously found that diacylglycerol kinase kappa (DGKk) is a main mRNA target of FMRP in cortical neurons. Here we show that diacylglycerol kinase kappa (DGKk), when modified as to become FMRP-independent and delivered into the brain of adolescent mice using adeno-associated viral vectors, corrects brain diacylglycerol and phosphatidic acid homeostasis and the main phenotypic behaviors of the Fmr1-KO mouse model of FXS. Thus, DGKk appears as a key triggering factor of FXS pathomechanism while providing a possible means of intervention for FXS gene therapy. One sentence summaryDGKk gene therapy in Fmr1-KO mouse model

neuroscience↗

bioRxiv2020

Extinct species identification from Upper Pleistocene bone fragments not identifiable from their osteomorphological studies by proteomics analysis

The ancient preserved molecules offer the opportunity to gain a better knowledge on the biological past. In recent years, bones proteomics has become an attractive method to study the animal biological origin, extinct species and species evolution as an alternative to DNA analysis which is limited by DNA amplification present in ancient samples and its contamination. However, the development of a proteomic workflow remains a challenge. The analysis of fossils must consume a low quantity of material to avoid damaging the samples. Another difficulty is the absence of genomic data for most of the extinct species. In this study, a proteomic methodology was applied to mammalian bones of 130,000 years old from the earlier Upper Pleistocene site of Scladina Cave (Belgium). Starting from 5 milligram samples, our results show a large majority of detected peptides matching collagen I alpha 1 and alpha 2 proteins with a sequence coverage up to 60%. Using sequence homology with modern sequences, a biological classification was successfully achieved and the associated taxonomic ranks to each bone were identified consistently with the information gained from osteomorphological studies and palaeoenvironmental and palaeodietary data. Among the taxa identified are the Felidae family, Bovinae subfamily, Elephantidae family and the Ursus genus. Amino acid substitutions on the collagens were identified providing new information on extinct species sequences and also helping in taxonomy-based clustering. Considering samples with no osteomorphological information, such as two bone retouchers, proteomics successfully identified the bovidae and ursidae families providing new information to the paleontologists on these objects. Combining osteomorphology studies and amino acid variations identified by proteomics, one retoucher was identified to be potentially from the Ursus spelaeus species.

paleontology↗