Project description:Marine sponges are essential for coral reefs to thrive and harbour a diverse microbiome that is thought to contribute to host health. Although the overall function of sponge symbionts has been increasingly described, in-depth characterisation of each taxa remains challenging, with many sponge species hosting up to 3,000 distinct microbial species. Recently, the sponge Ianthella basta has emerged as a model organism for symbiosis research, hosting only three dominant symbionts: a Thaumarchaeotum, a Gammaproteobacterium, and an Alphaproteobacterium and a range of other minor taxa. Here, we retrieved metagenome assembled genomes (MAGs) for >90% of I. basta’s microbial community which allowed us to make a complete metabolic reconstruction of the sponge’s microbiome, identifying metabolic complementarity between microbes, as well as the importance of symbionts present in low abundance. We also mined the metagenomes for putative viral sequences, highlighting the contribution of viruses to the overall metabolism of the sponge, and complement this data with metaproteomic sequencing to identify active metabolic pathways in both prokaryotes and viruses. This data now allows us to use I. basta as a model organism for studying host-microbe interactions and provides a basis for future (genomic) manipulative experiments.
Project description:To investigate the activity of sponge enhancers in vertebrates transgenic experiments was performed where sponge enhancers were inserted into zebrafish embryos and stable lines generated abstract: Transcription factors (TFs) bind DNA enhancer sequences to regulate gene transcription in animals. Unlike TFs, the evolution of enhancers has been difficult to trace because of their fast evolution. Here, we take enhancers in the sponge Amphimedon queenslandica and test their activity in zebrafish and mouse. Of the five sponge enhancers assessed, three were located in conserved syntenic gene regions that are unique to animals (Islet–Scaper, Ccne1–Uri, Tdrd3–Diaph3). Despite diverging over 700 million years ago and a dearth of sequence identity, sponge enhancers are able to drive cell type-specific reporter gene expression in vertebrates. Analysis of the type and frequency of TF binding motifs in the sponge Islet enhancer allowed for the identification of homologous enhancers in human and mouse, which show remarkably similar reporter expression patterns to the sponge enhancer. These findings uncover an unexpected deep conservation of enhancers and suggest that enhancers established early in metazoan evolution can remain functional through retention of combinations of transcription factor binding motifs despite substantial sequence divergence.
Project description:Opioids such as morphine have many beneficial properties as analgesics, however, opioids may induce multiple adverse gastrointestinal symptoms. We have recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. However, it is unclear how opioids modulate the gut homeostasis. By using a mouse model of morphine treatment, we studied effects of morphine treatment on gut microbiome. We characterized phylogenetic profiles of gut microbes, and found a significant shift in the gut microbiome and increase of pathogenic bacteria following morphine treatment when compared to placebo. In the present study, wild type mice (C57BL/6J) were implanted with placebo, morphine pellets subcutaneously. Fecal matter were taken for bacterial 16s rDNA sequencing analysis at day 3 post treatment. A scatter plot based on an unweighted UniFrac distance matrics obtained from the sequences at OTU level with 97% similarity showed a distinct clustering of the community composition between the morphine and placebo treated groups. By using the chao1 index to evaluate alpha diversity (that is diversity within a group) and using unweighted UniFrac distance to evaluate beta diversity (that is diversity between groups, comparing microbial community based on compositional structures), we found that morphine treatment results in a significant decrease in alpha diversity and shift in fecal microbiome at day 3 post treatment compared to placebo treatment. Taxonomical analysis showed that morphine treatment results in a significant increase of potential pathogenic bacteria. Our study shed light on effects of morphine on the gut microbiome, and its role in the gut homeostasis.