Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions
Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions.
Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions. We were interested to study the global reactions of bacteria with biodegradative properties under near-environmental as compared to laboratory culture conditions. We compared here the genome-wide responses of RW1 between regular laboratory batch growth on the aromatic substrates DBF and salicylate with growth in sandy soil with or without the same aromatic compounds. We analysed the cellular reactions immediately after introduction into the sand, during exponential growth and at stationary phase, all in carefully controlled and replicated experimental conditions.
Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions We were interested to study the global reactions of bacteria with biodegradative properties under near-environmental as compared to laboratory culture conditions. we compared here the genome-wide responses of RW1 between regular laboratory batch growth on the aromatic substrates DBF and salicylate with growth in sandy soil with or without the same aromatic compounds. We analysed the cellular reactions immediately after introduction into the sand, during lag phase, all in carefully controlled and replicated experimental conditions.
Project description:We sought to evaluate the brain gene expression profiles of male courtship display. To assess male display and courtship behavior, we designed a courtship preference assay. We evaluated social interactions between males and females using a 40 gallon tank design with a ‘rock’ habitat at one end and ‘sand’ at the other, separated by glass bottom. When parental rock species (Petrotilapia nigra (TaxId 526958), Maylandia zebra (TaxId 106582), Labeotropheus feulliborni) are placed in this tank paradigm, males court females over the rocks. Males of sand species (Mchenga conophorus, Aulonocara baenschi (TaxId 143496), Tramitichromis intermedius (TaxId 323801)) court females over sand and construct species appropriate bowers. When single rock x sand F1 males were placed in this set up with F1 females, males invariably courted females over the ‘rock’ habitat, suggesting genetic dominance. When two rock x sand F1 males were allowed to compete for F1 females in this tank paradigm, something interesting happened. One male, typically the larger, courted females over the rock habitat, and the other simultaneously constructed bowers to court females in the sand. We detected no difference in GSI (gonadal somatic index) between F1 males behaving as ‘socially rock’ vs. ‘socially sand.’ This observation of divergent behavior among interacting F1 brothers suggests an interaction between the genome and the social environment in these males.
Project description:Arbovirus transmission by sand flies is a growing public health concern, yet the early skin events shaping infection outcomes remain undefined. We establish a new mouse model of Toscana virus (TOSV) infection that incorporates sand fly salivary factors to mimic natural transmission. Saliva from two distinct sand fly genera significantly enhanced infection and promoted neurological signs and joint inflammation, recapitulating key features of human TOSV disease. In the skin, dermal macrophages and fibroblasts were the main infected cell types, but only fibroblasts generated infectious virus. Saliva reprogrammed fibroblasts into a wound-healing state permissive to viral replication, driving local viral amplification, systemic spread, and thereby clinical disease. These findings identify skin fibroblasts as central determinants of host susceptibility and reveal that sand fly saliva actively remodels the skin to exacerbate viral pathogenesis. This work redefines the skin’s role in sand fly-transmitted infection and highlights new targets for therapeutic and vaccine development.