Project description:Understanding natural defence mechanisms against parasites can be a valuable tool for the development of innovative therapies. In this study, we investigated the interplay between the gill mucus metabolome and microbiome of Chaetodon lunulatus, a butterflyfish known to avoid gill monogeneans whilst living amongst closely related parasitized species. In an attempt to identify metabolites and OTUs potentially involved in parasite defence mechanisms, we studied the metabolome (LC-MS/MS) and microbiome of several sympatric butterflyfish species, including the only non-parasitized species C. lunulatus. After observing significant differences between the metabolome and microbiome of parasitized versus non-parasitized fish (PCoA, ANOSIM), we obtained the discriminant metabolites and OTUs using a supervised analysis. Some of the most important discriminant metabolites were identified as peptides, and three new β-subunit haemoblogin-derived peptides from C. lunulatus (CLHbβ-1, CLHbβ-2 and CLHbβ-3) were purified, characterised and synthesised. We also identified specific bacterial families and OTUs typical from low-oxygen habitats in C. lunulatus gill mucus. By using a correlation network between the two datasets, we found a Fusobacteriaceae strain exclusively present in C. lunulatus highly correlated to the peptides. Finally, we discuss the possible involvement of these peptides and Fusobacteriaceae in monogenean avoidance by this fish species.
2020-11-25 | PXD018867 | Pride
Project description:The Beta-Diversity of Siganus fuscescens-Associated Microbial Communities from Different Habitats Increases with Body Weight
Project description:Studying how different genotypes respond to environmental variation is essential to understand the genetic basis of adaptation. The Mexican tetra, Astyanax mexicanus, has cave and surface‐dwelling morphotypes that have adapted to entirely different environments in the wild, and are now successfully maintained in lab conditions. While this has enabled the identification of genetic adaptations underlying a variety of physiological processes, few studies have directly compared morphotypes between lab‐reared and natural populations. Such comparative approaches could help dissect the varying effects of environment and morphotype, and determine the extent to which phenomena observed in the lab are generalizable to conditions in the field. To this end, we take a transcriptomic approach to compare the Pachón cavefish and their surface fish counterparts in their natural habitats and the lab environment. We identify key changes in expression of genes implicated in metabolism and physiology between groups of fish, suggesting that morphotype (surface or cave) and environment (natural or lab) both alter gene expression. We find gene expression differences between cave and surface fish in their natural habitats are much larger than differences in expression between morphotypes in the lab environment. However, lab‐raised cave and surface fish still exhibit numerous gene expression changes, supporting genetically encoded changes in livers of this species. From this, we conclude that a controlled laboratory environment may serve as an ideal setting to study the genetic underpinnings of metabolic and physiological differences between the cavefish and surface fish.
Project description:We combined an experimental microbiome of 11 bacterial strains isolated from the gut of native Caenorhabditis elegans. C. elegans were maintained on the experimental microbiome, Escherichia coli OP50 (control food source), or OP50 supplemented with cell-free media (CFM) from the experimental microbiome. For each of the three feeding conditions, RNA-seq was performed for wildtype (N2) worms or transgenic worms expressing amyloid beta 1-42 in their body wall muscle (GMC101).
Project description:In rodents, brown adipose tissue (BAT) contributes to whole body energy expenditure and low BAT activity is related to hepatic fat accumulation, partially attributable to the gut microbiome. Little is known of these relationships in humans. In adults (n=60), we assessed hepatic fat and cold-stimulated BAT activity utilizing magnetic resonance imaging and the gut microbiome with 16S sequencing. We transplanted gnotobiotic mice with feces from humans to assess the transferability of BAT activity and NAFLD through the microbiome. Individuals with NAFLD (n=29) had lower BAT activity than those without and BAT activity was inversely related to hepatic fat. Although the fecal microbiome was different in those with NAFLD, no differences were observed in relation to BAT activity and neither of these phenotypic traits were transmissible through fecal transplant to gnotobiotic mice. Thus, low BAT activity is associated with hepatic steatosis but this is not mediated through the gut microbiota.