Handler, A. M. | bioRxiv Science

bioRxiv2024

Gut Commensal Bacteria-Derived Methionine is Required for Host Reproduction by Modulating RNA m6A Methylation of the Insulin Receptor

Gut commensal bacteria promote host reproduction by modulating metabolism and nutrition, yet the molecular mechanisms by which microbes modulate reproduction remain unclear. Here, we show that gut commensal bacteria promote host reproduction by providing amino-acid methionine, which controls the RNA m6A modification level of insulin receptor (InR) in the ovary of the invasive insect Bactrocera dorsalis. RNA m6A levels and S-adenosyl-methionine (SAM) titers in the ovaries were sharply reduced in antibiotic treated B. dorsalis compared with untreated insects, resulting in arrested ovarian development and decreased fecundity. The intestinal commensal bacteria Enterobacter hormaechei or the E. hormaechei-derived metabolite methionine restored the decreased RNA m6A level and the reproductive defects. Notably, knockdown of METTL3 and METTL14, two genes encoding the RNA m6A methyltransferases, led to a decrease in the mRNA level of InR and underdevelopment of ovaries in B. dorsalis, and blocked the promoting effect of methionine on ovarian development and fecundity. Collectively, our study identifies an unrecognized role of RNA m6A methylation modification that underlies microbial control of host reproduction. Our findings further expand the functional landscape of m6A modification to include nutrient-dependent control of ovarian development and highlight the essential role of epigenetic regulation in microbe-host interactions.

microbiology↗

bioRxiv2018

The Genomic Basis of Arthropod Diversity

BackgroundArthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods.\n\nResultsUsing 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality and chemoperception.\n\nConclusionsThese analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity.

genomics↗