Proteomic analysis of germ-free Drosophila melanogaster
Ontology highlight
ABSTRACT: A method for the long-term maintenance of germ-free flies was established using aseptic isolators. The methodology effectively and reliably yields large numbers of germ-free flies in homogeneous cultures. Germ-free flies exhibited increased lifespan (only female flies) and decreased egg production, markedly reduced fat storage, less midday sleep, and enhanced aggressiveness (male flies). Fructilactobacillus—a species of fly intestinal microbes—was re-colonized in germ-free flies, and these gnotobiotic flies were successfully maintained for numerous generations. The proteome of those flies were analyzed.
Project description:To understand the effect of microbes on microRNAs in aorta, in this study, we examined expression of microRNA in the aorta of male (10 weeks old) germ-free mice and pathogen-free mice (control).
Project description:Innate immune responses contributed to the containment of intestinal microbes. We used microarrays to examine transcriptional profiles of imflamed guts raised in convential or germ-free conditions. We found that gut inflammation and the gut microbiome regulate the expression of several hundred host genes.
Project description:We identified Elf3 as a conserved microbially responsive transcription factor and generated an elf3 mutant zebrafish allele to test whether it mediates host responses to microbes. We performed bulk RNA-sequencing of elf3 wildtype and mutant larvae reared without (germ-free) or with (conventionalized) the presence of microbes. We found that elf3 does mediate host-microbiota interactions in zebrafish and has an important role in the induction of many immune responsive genes.
Project description:Conventionally raised and germ-free newly weaned male Sprague-Dawley rats were fed a basal diet or a diet supplemented with digestion resistant carbohydrates in the form of inulin, resistant starch or konjac flour. Gene expression in colon tissue was measured to characterise interaction between food, microbes and host.
Project description:We performed RNA-seq, H3K27ac ChIP-seq, and HNF4a ChIP-seq on jejunal intestinal epithelial cells, which are primarily responsible for the absorption of fatty acids, in four conditions: Germ-free (GF), Germ-free plus high fat meal (GF+HFM), ex-GF colonized with a conventional microbiota for 2 weeks (Colonized, CV), and Colonized plus high fat meal (CV+HFM). We, for the first time, map genomewide HFM responsive regulatory regions in the intestine. We identify that in the absence of microbes the HNF4a transcriptional program supports a FAO program in enterocytes while suppressing a proliferation program.
Project description:We report that adhesion of microbes to intestinal epithelial cells is a critical cue for Th17 induction. SFB colonized in the intestine of mice can adhere to mouse small intestinal epithelial cells and induce intestinal Th17 cells. However, SFB colonized in rats cannot adhere to mouse intestinal epithelial cells and induce Th17 cells. Likewise, Citrobacter rodentium (WT) can adhere to mouse colonic epithelial cells and induce Th17 cells, but non-adherent mutant of C. rodentium (Δeae) cannot induce Th17 cells. To examine the influence of adherent bacteria on intestinal epithelial cells, we performed RNA seq. Germ free mice were orally inoculated with M-SFB or R-SFB and total RNA was isolated from small intestinal epithelial cells 1 week after inoculation. Alternatively, germ free mice were orally inoculated with C. rodentium WT or eae mutant and total RNA was isolated from colonic epithelial cells 5 days after inoculation. The gene expression of small intestinal epithelial cells isolated from small intestine of germ free mice (2 mice), mice monocolonized with M-SFB (2 mice) or R-SFB (3 mice), and colon of germ free mice (3 mice), mice monocolonized C. rodentium WT (3 mice) or eae mutant (3 mice).
Project description:We hypothesized that there were genes involved in the maintenance of intestinal tolerance to commensal bacteria. These genes should meet the following criteria: expressed in intestines, upregulated in the presence of commensal bacteria and downregulated in absence of microbes. To find these genes, we collected small intestines from postnatal mice that neither affected by the bacteria nor by the food, adult mice bred in germ-free or specific pathogen-free conditions, and adult SPF mice treated with antibiotics. We therefore performed bulk RNA sequencing using these cells.
Project description:Conventionally raised and germ-free newly weaned male Sprague-Dawley rats were fed a basal diet or a diet supplemented with digestion resistant carbohydrates in the form of inulin, resistant starch or konjac flour. Gene expression in colon tissue was measured to characterise interaction between food, microbes and host. 2 colour microarray, reference design. Biological replicates: 6 for all groups except for conventionally raised rats fed inulin, which consisted of 5 biological replicates
Project description:The circadian clock and associated feeding rhythms have a profound impact on metabolism and the gut microbiome. To what extent microbiota reciprocally affect daily rhythms of physiology in the host remains elusive. Here, we analyzed transcriptome and metabolome profiles of male and female germ-free mice. While mRNA expression of circadian clock genes revealed subtle changes in liver, intestine, and white adipose tissue, germ-free mice showed considerably altered expression of genes associated to rhythmic physiology. Strikingly, absence of microbiome severely compromised liver sexual dimorphism, showing strongly attenuated sex-specific rhythmicity. The resulting feminization of male and masculinization of female germ-free animals is likely caused by altered sexual development and growth hormone secretion, associated to differential activation of xenobiotic receptors. This defines a novel mechanism by which the microbiome regulates host metabolism.
Project description:Transcriptomics (using DNA microarrays) was used to quantitatively compare the terminal ileum from conventional and germ-free mice (female and male; C57BL/10A and BALB/c strains).