Project description:In this work we took 9 samples from brain and 6 samples from muscle of the African turquoise killifish (Nothobranchius furzeri) at 3.5, 8.5 and 14 weeks. Total RNA was sequenced and circRNAs were detected.
Project description:Suspended animation (e.g. hibernation, diapause) allows organisms to survive extreme environments. But the mechanisms underlying the evolution of suspended animation states are unknown. The African turquoise killifish has evolved diapause as a form of suspended development to survive the complete drought that occurs every summer. Here, we show that gene duplicates – paralogs – exhibit specialized expression in diapause compared to normal development in the African turquoise killifish. Surprisingly, paralogs with specialized expression in diapause are evolutionarily very ancient and are present even in vertebrates that do not exhibit diapause. To determine if evolution of diapause is due to the regulatory landscape rewiring at ancient paralogs, we assessed chromatin accessibility genome-wide in fish species with or without diapause. This analysis revealed an evolutionary recent increase in chromatin accessibility at very ancient paralogs in African turquoise killifish. The increase in chromatin accessibility is linked to the presence of new binding sites for transcription factors, likely due to de novo mutations and transposable element (TE) insertion. Interestingly, accessible chromatin regions in diapause are enriched for lipid metabolism genes, and our lipidomics studies uncover a striking difference in lipid species in African turquoise killifish diapause, which could be critical for long-term survival. Together, our results show that diapause likely originated by repurposing pre-existing gene programs via recent changes in the regulatory landscape. This work raises the possibility that suspended animation programs could be reactivated in other species for long-term preservation via transcription factor remodeling and suggests a mechanism for how complex adaptations evolve in nature.
Project description:Protein aggregation is a hallmark of age-related neurodegeneration. Yet whether aggregation drives age-related dysfunction and disease in other tissues is poorly understood. Here, we leverage the African turquoise killifish to obtain a systematic understanding of protein aggregation in seven tissues in an aging vertebrate.
Project description:In order to understand molecular basis of cardiac ageing in killifish, we have performed RNA Seq on the ventricular regions of young and aged killifish. Experiment was performed in biological triplicates.
Project description:With advancing age, senescent cells accumulate as they are not efficiently cleared by the immune system anymore. Via a senescence-associated secretory phenotype, chronic senescent cells alter the microenvironment, creating an unfavorable milieu for neurogenesis and neurorepair. Using an innovative and rapid aging model, the African turquoise killifish, we have previously demonstrated a dramatic decline in neurogenic potential of non-glial progenitors with age. Even after traumatic brain injury, progenitor proliferation and neuron production was very low in aged killifish in comparison to young adult killifish, and overall neurorepair was incomplete. In the present study, we validated if the senolytic cocktail dasatinib and quercetin (D+Q) could reboot the neurogenic output by clearing chronic senescent cells from the aged killifish brain to re-create the necessary supportive environment. Our results confirm that the aged killifish telencephalon holds a very high senescent cell burden, which we could diminish by short-term systemic D+Q treatment. As a consequence of D+Q administration, proliferation of non-glial progenitors increased and more new neurons were generated and migrated into the parenchyma after injury. Injury-induced inflammation and glial scarring, a phenomenon only seen in aged killifish, remained unaltered. Senolytic treatment with D+Q might thus hold promise for improving brain function in aged populations, and is especially interesting for reviving the neurogenic potential of an already aged central nervous system.
Project description:To study the effect of dietary restriction on killifish, we generated transcriptomes (RNA-seq) for the livers and brains of male and female killifish that had been subjected to different dietary treatements.
Project description:The RNA-seq data contain 3 tissues (brain, liver, skin) of N. furzeri strains MZM-0410 and GRZ plus 2 biological replicates of brain of 6 other killifish species. Jena Centre for Systems Biology of Ageing - JenAge (www.jenage.de)
Project description:Purpose: We are using the illumina sequencing to compare the false positive and true positive circular RNA findings to confine the method to detect the true circular RNAs Methods: The testis whole transcriptome profiling was generated from 4-week mouse testis using illumina Nextseq, duplicated. The sequence reads that passed quality filters were analyzed at the transcript isoform level with TopHat followed by Cufflinks. Results: our data suggest that circular RNAs identified based on junction sequences in the RNA-seq reads, especially those from Illumina Hiseq sequencing, mostly result from template-switching events during reverse transcription by MMLV-derived reverse transcriptases. It is critical to employ reverse transcriptases lacking terminal transferase activity (e.g., MonsterScript) to construct sequencing library or perform RT-PCR for identification and quantification of true circular RNAs. Conclusions: Our study represents the first detailed analysis of retinal transcriptomes, with biologic replicates, generated by RNA-seq technology. The optimized data analysis workflows reported here should provide a framework for comparative investigations of expression profiles. Our results show that NGS offers a comprehensive and more accurate quantitative and qualitative evaluation of mRNA content within a cell or tissue. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions. The wild type mouse testis RNAs were constructed NGS library by two different enzyme, then parallel sequenced in illumina Nextseq