The abilities of an organism to cope with extrinsic stresses and activate cellular stress responses decline during aging. The signals that modulate stress responses in aged animals remain to be elucidated. Here, we discover that feeding Caenorhabditis elegans (C. elegans) embryo lysates to adult worms enabled the animals to activate the mitochondrial unfolded protein response (UPR
N6-Methyldeoxyadenine (6mA) has been rediscovered as a DNA modification with potential biological function in metazoans. However, the physiological function and regulatory mechanisms regarding the establishment, maintenance and removal of 6mA in eukaryotes are still poorly understood. Here we show that genomic 6mA levels change in response to pathogenic infection in Caenorhabditis elegans (C. elegans). We further identify METL-9 as the methyltransferase that catalyzes DNA 6mA modifications upon pathogen infection. Deficiency of METL-9 impairs the induction of innate immune response genes and renders the animals more susceptible to pathogen infection. Interestingly, METL-9 functions through both 6mA-dependent and -independent mechanisms to transcriptionally regulate innate immunity. Our findings reveal that 6mA is a functional DNA modification in immunomodulation in C. elegans.
With the rapid development of new and innovative applications for mobile devices like smart phones, advances in battery technology have not kept pace with rapidly growing energy demands. Thus energy consumption has become a more and more important issue of mobile devices. To meet the requirements of saving energy, it is critical to monitor and analyze the energy consumption of applications on smart phones. For this purpose, we develop a smart energy monitoring system called SEMO for smart phones using Android operating system. It can profile mobile applications with battery usage information, which is vital for both developers and users.
ABSTRACT While N 6 -methyldeoxyadenine (6mA) modification has been linked to fundamental regulatory processes in prokaryotes, its prevalence and functional implications in eukaryotes are controversial. Here, we report 6mA-Sniper to quantify 6mA sites in eukaryotes at single-nucleotide resolution. With 6mA-Sniper, we delineated an accurate 6mA profile in C. elegans with 2,034 sites, significantly enriched on sequences of [GC]G A G motif. Twenty-six of 39 6mA events with MnlI restriction endonuclease sites were experimentally verified, demonstrating the feasibility of this method. Notably, the enrichment of these 6mA sites on a specific sequence motif, their within-population conservation and the combinatorial patterns, and the selective constrains on them jointly support an active model for the shaping of the profile by some undiscovered methyltransferases. In a joint study ( Cell Research , in revision), Ma et al. reported METL-9 as a new methyltransferase in shaping the basal and stress-dependent 6mA profile in C. elegans . Notably, with the 6mA profile identified by 6mA-Sniper at single-nucleotide resolution, we found that the levels of 6mAs are significantly decreased in strains with the removal of METL-9 (METL-9 KO-OP50), while generally increased after P. aeruginosa infection, further verified the efficiency of 6mA-Sniper in accurately pinpointing 6mA sites. Moreover, for the regions marked by 998 6mA sites emerged specifically after the infection, we identified an enrichment of the upregulated genes after the infection. The gene upregulations are likely mediated through a mutual exclusive crosstalk between 6mA and H3K27me3 modification, as supported by their co-occurrence, and the signal of increased H3K27me3 at regions marked by 6mAs depleted in METL-9 KO-OP50 strains. Notably, in different C. elegans strains, the cross-strain genetic variants removing 6mA sites are associated with the decreased expression of their host genes, and the removal of two randomly-selected 6mA events with genome editing directly decreased the expression of their host genes. We thus highlight 6mA regulation as a previously-neglected regulator of transcriptome in eukaryotes.
While N 6 -methyldeoxyadenine (6mA) modification is a fundamental regulation in prokaryotes, its prevalence and functions in eukaryotes are controversial. Here, we report 6mA-Sniper to quantify 6mA sites in eukaryotes at single-nucleotide resolution, and delineate a 6mA profile in Caenorhabditis elegans with 2034 sites. Twenty-six of 39 events with Mnl I restriction endonuclease sites were verified, demonstrating the feasibility of this method. The levels of 6mA sites pinpointed by 6mA-Sniper are generally increased after Pseudomonas aeruginosa infection, but decreased in strains with the removal of METL-9, the dominant 6mA methyltransferase. The enrichment of these sites on specific motif of [GC]G A G, the selective constrains on them, and their coordinated changes with METL-9 levels thus support an active shaping of the 6mA profile by methyltransferase. Moreover, for regions marked by 6mA sites that emerged after infection, an enrichment of up-regulated genes was detected, possibly mediated through a mutual exclusive cross-talk between 6mA and H3K27me3 modification. We thus highlight 6mA regulation as a previously neglected regulator in eukaryotes.