Project description:This SuperSeries is composed of the following subset Series: GSE11944: Mucosal Glycan Foraging Enhances the Fitness and Transmission of a Saccharolytic Human Distal Gut Symbiont GSE11953: Mucosal Glycan Foraging Enhances the Fitness and Transmission of a Saccharolytic Human Distal Gut Symbiont: ECF mutant GSE11962: Growth of B. thetaiotaomicron on purified host mucosal glycans and glycan fragments Refer to individual Series
Project description:Host-derived factors are sucked into midgut of mosquitoes during natural malaria transmission, but their influence on malaria transmission is largely unknown. We reported that mouse complement C3 taken into mosquitoes significantly promoted malaria transmission either in laboratory or in field. This effect was attributed to the reduction of microbiota abundance in mosquito midgut by host-derived C3 through direct lyses the predominant symbiont bacteria Elizabethkingia anopheles. Elizabethkingia anopheles symbiont bacteria were demonstrated to be detrimental to malaria sexual stages in mosquitoes. Strikingly, the promoted effect of host C3 on malaria transmission was confirmed by laboratory mosquitoes membrane-feeding on Plasmodium falciparum. Therefore, we reveal a novel strategy of malaria parasite to utilize host complement C3 to promote its transmission, and the administration of C3 inhibitor would provide us a novel strategy to control malaria transmission.
Project description:Symbiosis is a ubiquitous phenomenon in nature, and these inter-species interactions have a massive impact on organisms, shaping the world around us today. The relationship between the partners in microbial symbioses have been described as existing along a parasitism-mutualism continuum, and the dynamics of this continuum are dependent upon numerous genotypic and environmental factors. Theoretical and experimental studies show that vertical transmission (VT) leads to the evolution of mutualistic traits, whereas horizontal transmission (HT) facilitates the emergence of parasitic features. However, these studies focused on phenotypic data, and we know little about underlying molecular changes at the genomic level. Here we show that a dramatic shift in the frequency of genetic variants, coupled with major changes in gene expression, allow an obligate intracellular bacterial symbiont to alter its position in the mutualism-parasitism continuum depending on the mode of between-host transmission. We found that increased virulence in horizontally transmitted chlamydiae residing in amoebae was a result of processes occurring at the infectious stage of the chlamydia’s developmental cycle. Specifically, genes involved in energy production required for extracellular survival as well as the type III secretion system (T3SS) - the symbiont’s primary virulence mechanism - were significantly upregulated. Our results identify the genomic and transcriptomic dynamics sufficient to favor parasitic or mutualistic strategies.
2020-01-20 | GSE138099 | GEO
Project description:Intracellular symbiont with vertical transmission that is widespread across insect orders
Project description:Bacterial outer-membrane vesicles (OMVs) and the cargo they carry are increasingly recognized as a means of communication between microbial symbionts and the cells of their host. However, few studies have focused on the biochemical and molecular mechanisms underlying OMV-signaling during symbiosis onset and development. We show here that SypC, an OMV protein of the bioluminescent symbiont Vibrio fischeri, is taken up by cells of the squid host Euprymna scolopes where it assumes a new function, i.e., the facilitation of symbiont-induced light-organ morphogenesis. SypC is a Wza-like outer-membrane protein found in host-associated Vibrionaceae, and is essential for V. fischeri biofilm formation. Colonization or direct treatment with V. fischeri OMVs triggers host development, which is reduced or delayed if the host is instead exposed to a sypC mutant or its OMVs. RNA-seq analyses comparing light-organs colonized by the mutant versus its parent strain revealed differential expression of host genes involved in immune responses and tissue morphogenesis. Immunocytochemical imaging revealed that, within the light-organ crypts, SypC-bearing OMVs are taken up by the host’s macrophage-like cells, revealing the mechanism by which SypC travels throughout the tissue to trigger morphogenesis. Taken together, the data show that, in addition to its role in biofilm formation, SypC has a second function promoting colonization and the induction of symbiotic-tissue development. These findings provide a critical piece of a puzzle whereby a rich array of host and symbiont molecules work in concert to orchestrate normal symbiont colonization and host development within the first hours to days of symbiosis.
Project description:In order to understand host responses to symbiont strains with and without an intact symbiotic type 6 secretion system, we infected Dictyostelium discoideum with wildtype vs. ∆tssH Paraburkholderia bonniea and collected samples in a time series to capture the early stages of symbiotic association.
Project description:To investigate the potential vertical transmission of chronic stress to the unexposed larvae, to report novel consequences of paternally inherited chronic stress at molecular level
Project description:We subjected three inshore and four offshore genotypes of the coral Orbicella faveolata to 30, 31, 32, or 33ºC for 31 days and measured photochemical efficiency (Fv/Fm), the types and relative abundance of dinoflagellate endosymbionts, and gene expression of the host and symbiont. All inshore coral genotypes, regardless of symbiont type, were significantly more thermotolerant than offshore genotypes based on declines in Fv/Fm. The most heat-tolerant inshore genotype (In1) was dominated by Durusdinium trenchii; all other genotypes were Breviolum-dominated, suggesting local adaptation or acclimatization contributes to the heat tolerance of inshore genotypes. After 31 days of heat stress, all coral genotypes (except In2) had lost most of their Breviolum and became dominated by D. trenchii. Host genotype In1 presented unique expression patterns of genes involved in heat shock response, immunity, and protein degradation. There were few changes in the symbiont transcriptomes of inshore corals under heat stress, but significant changes in symbiont gene expression from the offshore colonies, including increases in ribosomal and photosynthetic proteins. These data show that the differential thermotolerance between inshore and offshore O. faveolata in the Florida Keys is associated with statistically significant differences in both host and symbiont gene expression that provide insights into the mechanisms underlying holobiont heat tolerance.