Researchers from Israel and Japan describe ties between circadian rhythms, gut microbiome features, and metabolome patterns. The team took an integrated multi-omics approach, including 16S ribosomal RNA sequencing, metagenomic sequencing, host RNA sequencing, to track microbe community membership in mucosal-associated colon sites at different times of day, in relation to host gene expression, histone modifications, and more. In the process, it detected diurnal oscillations in gut microbe composition, location, and metabolism — shifts that appeared to impact host epigenetics, gene expression, and metabolism in the gut and other tissues.
An Austrian team takes a look at the processes at play as paternal DNA lesions introduced by DNA methylation during zygotic reprogramming are repaired in mice. With the help of DNA labeling and mutant mouse zygote models, the team found that zygotic reprogramming spurred on by the DNA methylation player Tet3 prompts DNA lesions in paternal DNA. Those repairs, it reports, are followed by surveillance mechanisms that repaired by cohesin-dependent processes, activating a Chk1-regulated checkpoint if these repairs are not completed by the time cells are set to divide. "We propose the zygotic checkpoint senses DNA lesions generated during paternal DNA demethylation and ensures reprogrammed loci are repaired before mitosis to prevent chromosome fragmentation, embryo loss, and infertility," the authors say.
Finally, researchers from the Genome Institute of Singapore, the University of California, Los Angeles, and elsewhere report on a shared epigenetic signature identified in genetically diverse autism spectrum disorder cases. Using an acetylation-wide association study approach, the team compared histone marks — measured by chromatin immunoprecipitation sequencing — in hundreds of post-mortem brain samples from prefrontal cortex, temporal cortex, and cerebellum brain regions in 45 individuals with ASD and 49 unaffected controls. In the prefrontal and temporal cortex, the investigators saw apparent acetylome signatures associated with ASD, including differences in histone marks falling near genes related to synapse formation, neuronal migration, and brain development. GenomeWeb has more on the study, here.