Only skin deep: shared genetic response to the deadly chytrid fungus in susceptible frog species
Ontology highlight
ABSTRACT:
ORGANISM(S): Rana muscosa Rana sierrae
PROVIDER: GSE34235 | GEO | 2012/05/01
SECONDARY ACCESSION(S): PRJNA149799
REPOSITORIES: GEO
Similar Datasets
Project description:Amphibian populations around the world are threatened by an emerging infectious pathogen, the chytrid fungus Batrachochytrium dendrobatidis (Bd). How can a fungal skin infection kill such a broad range of amphibian hosts? And why are certain species particularly susceptible to the impacts of Bd? Here we use a genomics approach to understand the genetic response of multiple susceptible frog species to Bd infection. We characterize the transcriptomes of two closely-related endangered frog species (Rana muscosa and Rana sierrae) and analyze whole genome expression profiles from frogs in controlled Bd-infection experiments. We integrate the Rana results with a comparable dataset from a more distantly-related susceptible species (Silurana tropicalis). We demonstrate that Bd-infected frogs show massive disruption of skin function and show no evidence of a robust immune response. The genetic response to infection is shared across the focal susceptible species, suggesting a common effect of Bd on susceptible frogs. A total of five (12-plex) chips were analyzed from 60 samples comprising 2 conditions (control and infected), 3 tissues (skin, liver and spleen) and 2 timepoints (early and late). Three biological replicates were used for each condition and tissue at each time point. Twentyfour arrays were analyzed for skin samples, 24 for liver, and 12 for spleen. The same dye, Cy5, was used for all samples.
2012-04-30 | E-GEOD-34235 | biostudies-arrayexpress
Project description:This experiment examined the transcriptional response of juvenile amphibian hosts (common frog, Rana temporaria) to two important amphibian pathogens: Batrachochytrium dendrobatidis (Bd) and Ranavirus. Common frogs are non-model organisms which do not have a reference genome.
2015-07-10 | E-MTAB-3632 | biostudies-arrayexpress
Project description:Emerging infectious diseases are of great concern for both wildlife and humans. Several highly virulent fungal pathogens have recently been discovered in natural populations, highlighting the need for a better understanding of fungal-vertebrate host-pathogen interactions. Because most fungal pathogens are not fatal in the absence of other predisposing conditions, host-pathogen dynamics for deadly fungal pathogens are of particular interest. The chytrid fungus Batrachochytrium dendrobatidis (hereafter Bd) infects hundreds of species of frogs in the wild. It is found worldwide and is a significant contributor to the current global amphibian decline. However, the mechanism by which Bd causes death in amphibians, and the response of the host to Bd infection, remain largely unknown. Here we use whole-genome microarrays to monitor the transcriptional responses to Bd infection in the model frog species, Silurana (Xenopus) tropicalis, which is susceptible to chytridiomycosis. To elucidate the immune response to Bd and evaluate the physiological effects of chytridiomycosis, we measured gene expression changes in several tissues (liver, skin, spleen) following exposure to Bd. We detected a strong transcriptional response for genes involved in physiological processes that can help explain some clinical symptoms of chytridiomycosis at the organismal level. However, we detected surprisingly little evidence of an immune response to Bd exposure, suggesting that this susceptible species may not be mounting efficient innate and adaptive immune responses against Bd. The weak immune response may be partially explained by the thermal conditions of the experiment, which were optimal for Bd growth. However, many immune genes exhibited decreased expression in Bd-exposed frogs compared to control frogs, suggesting a more complex effect of Bd on the immune system than simple temperature-mediated immune suppression. This study generates important baseline data for ongoing efforts to understand differences in response to Bd between susceptible and resistant frog species and the effects of chytridiomycosis in natural populations.
2009-08-31 | GSE16852 | GEO
Project description:Chytridiomycosis is an emerging infectious disease of amphibians caused by the chytrid Batrachochytrium dendrobatidis (Bd). The disease has been associated with global amphibian declines and is driving the species in the wild to extinction. Using DNA microarray technology we have analysed transcriptional changes in Xenopus tropicalis during the course (7 and 42 days) of infection by Bd under warm (26oC) and cold (18oC) temperatures.
2009-10-22 | E-MEXP-1936 | biostudies-arrayexpress
Project description:Determining the mechanisms of host-pathogen interaction is critical for understanding and mitigating infectious disease. Mechanisms of fungal pathogenicity are of particular interest given the recent outbreaks of fungal diseases in wildlife populations. Our study focuses on Batrachochytrium dendrobatidis (Bd), the chytrid pathogen responsible for amphibian declines around the world. Previous studies have hypothesized a role for several specific families of secreted proteases as pathogenicity factors in Bd, but the expression of these genes has only been evaluated in laboratory growth conditions. Here we conduct a genome-wide study of Bd gene expression under two different nutrient conditions. We compare Bd gene expression profiles in laboratory growth media and in host tissue (i.e., frog skin). A large proportion of genes in the Bd genome show increased expression when grown in host tissue, indicating the importance of studying pathogens in their infection environment. A number of gene classes show particularly high levels of expression in host tissue, including three families of secreted proteases (metallo-, serine- and aspartyl-proteases), adhesion genes, lipase-3 encoding genes, and a group of phylogenetically unusual crinkler-like effectors. We discuss the roles of these different genes as putative pathogenicity factors and discuss what they can teach us about Bd's metabolic targets, host invasion, and pathogenesis. One 12-plex chip was analyzed from 12 RNA samples extracted from Batrachochytrium dendrobatidis grown in 2 substrates. Six biological replicates were used for each substrate - sterile frog skin and tryptone nutrient broth. The same dye, Cy5, was used for all samples.
2012-11-01 | E-GEOD-37135 | biostudies-arrayexpress
Project description:Global amphibian declines and extinction events are currently occurring at an unprecedented rate. While various factors are influencing these declines, one factor that is readily identifiable is disease. Specifically, the fungal pathogen Batrachochytrium dendrobatidis is thought to play a major role in amphibian declines in tropical and neotropical regions of the globe. While the effects of this chytrid fungus have been shown to be devastating, certain individuals and relict populations have shown resistance. This resistance has been attributed in part to the cutaneous microbiome. Many identified bacterial species that make up the microbiome have shown anti-B. dendrobatidis activity in vitro. One bacteria that is commonly associated as being a member of the amphibian microbiome across amphibian species and shows such anti-B. dendrobatidis activity is Serratia marcescens. Here, we look at transcriptomic shifts in gene expression of S. marcescens (high homology to strain WW4) in response to both live and heat-killed B. dendrobatidis.
2016-07-11 | GSE84057 | GEO
Project description:Determining the mechanisms of host-pathogen interaction is critical for understanding and mitigating infectious disease. Mechanisms of fungal pathogenicity are of particular interest given the recent outbreaks of fungal diseases in wildlife populations. Our study focuses on Batrachochytrium dendrobatidis (Bd), the chytrid pathogen responsible for amphibian declines around the world. Previous studies have hypothesized a role for several specific families of secreted proteases as pathogenicity factors in Bd, but the expression of these genes has only been evaluated in laboratory growth conditions. Here we conduct a genome-wide study of Bd gene expression under two different nutrient conditions. We compare Bd gene expression profiles in laboratory growth media and in host tissue (i.e., frog skin). A large proportion of genes in the Bd genome show increased expression when grown in host tissue, indicating the importance of studying pathogens in their infection environment. A number of gene classes show particularly high levels of expression in host tissue, including three families of secreted proteases (metallo-, serine- and aspartyl-proteases), adhesion genes, lipase-3 encoding genes, and a group of phylogenetically unusual crinkler-like effectors. We discuss the roles of these different genes as putative pathogenicity factors and discuss what they can teach us about Bd's metabolic targets, host invasion, and pathogenesis.
2012-11-01 | GSE37135 | GEO
Project description:Boreal toads (Anaxyrus boreas boreas) of the Southern Rocky Mountain population are declining due to the introduction of the chytrid fungus Batrachochytrium dendrobatidis (Bd). Boreal toads in Colorado are generally susceptible to Bd infection, but some Bd-tolerant populations persist in parts of the Southern Rocky Mountain and broader Eastern boreal toad population. We conducted a Bd challenge with lab-reared sibling toads from Bd-susceptible Colorado and purportedly Bd-tolerant Utah populations and report on transcriptomic responses to Bd during late infection in skin and liver tissue. Fewer immune genes were expressed in response to Bd in Colorado toads, but with greater upregulation compared to Utah toads, indicating a dysregulated immune response. Signatures of Bd-tolerance in Utah toads included more moderate upregulation in immune gene expression and a significantly enriched suite of gene functions related to innate and adaptive immune responses. Our transcriptomic results support the notion that Utah toads are tolerant to Bd, rather than resistant, carrying Bd loads similar to Colorado yet having a unique transcriptomic profile and presenting minimal clinical signs of chytridiomycosis. We conclude that closely related populations have divergent transcriptomic responses to Bd with a dysregulated immune response in Bd-susceptible toads.
2023-10-04 | GSE244617 | GEO
Project description:Along with the prevalence of edible frog farming in China, the outbreak of a deadly infectious frog diseased, called frog meningitis (or cataracts and torticollis), has increased in frequency and geographical range dramatically. More than 10 bacterial species, belonging to 8 genera, has been reported as its potential pathogens. Diseased frogs typically manifest as torticollis, cataracts, edema and finally death, resulting in huge economic loss. Currently, the pathogenesis of this disease has not been investigated systematically. Here, we summarized the pathological stages of infected black-spotted frogs (Pelophylax nigromaculata) in Sichuan province according to their symptoms, typically progressing of pathological stage with only torticollis to stage with both torticollis and cataracts. On the basis, we analyzed the pathogenesis by a combination of comparative environmental analysis, microbiomics and transcriptomics. Results showed that more severely infected frog ponds tended to have lower water alkalinity. Elizabethkingia miricola was the only bacteria, whose abundance was positively correlated with the disease degree, and it has absolute dominance in the eyeball and brain of some torticollis-cataracts frogs. E. miricola and several other bacterial species, which belonged to pathogenic genera of meningitis, might be constitutively existed in the resident microbiome in frogs or their environment. Activations of infectious processes and immune responses related pathways were the major difference between health and diseased frogs at transcriptional level. Despite transcriptional activation of immunoglobulins was observed in both torticollis-only and torticollis-cataracts frogs, transcriptional activation of innate immune system (including MHC, toll-like receptor, and cathelicidins) in brain, inflammation system (including interleukins and receptors) in brain, and acute phase proteins (including transferrins and fibrinogens) in both liver and brain was only observed in torticollis-cataracts frogs. Activation of inflammation and the resulting higher vascular permeability in torticollis-cataracts frogs could explain the severe brain infection, cooccurrence of torticollis and cataracts, and systemic edema in torticollis-cataracts frogs. In addition, meningitis could also result in reduction in energy production in liver, and this was more severe in torticollis-cataracts frogs. In conclusion, our results suggested environment might have a role in susceptibility of frog meningitis. E. miricola was the most likely pathogen of meningitis of black-spotted frogs in Sichuan. Refer to the pathogenesis of human meningitis, excessive inflammation likely played a critical role in the progress of frog meningitis, and its resulted sepsis and organ failure might be the direct cause of infected frogs.
2020-06-05 | GSE132282 | GEO
Project description:The Global Pandemic Lineage (GPL) of the amphibian pathogen Batrachochytrium dendrobatidis (Bd) has been described as a main driver of amphibian extinctions on nearly every continent. Near complete genome of three Bd-GPL strains have enabled studies of the pathogen but the genomic features that set Bd-GPL apart from other Bd lineages is not well understood due to a lack of high-quality genome assemblies and annotations from other lineages. We used long-read DNA sequencing to assemble high-quality genomes of three Bd-BRAZIL isolates and one non-pathogen outgroup species Polyrhizophydium stewartii (Ps) strain JEL0888, and compared these to genomes of previously sequenced Bd-GPL strains. The Bd-BRAZIL assemblies range in size between 22.0 and 26.1 Mb and encode 8495-8620 protein-coding genes for each strain. Our pan-genome analysis provided insight into shared and lineage-specific gene content. The core genome of Bd consists of 6278 conserved gene families, with 202 Bd-BRAZIL and 172 Bd-GPL specific gene families. We discovered gene copy number variation in pathogenicity gene families between Bd-BRAZIL and Bd-GPL strains though none were consistently expanded in Bd-GPL or Bd-BRAZIL strains. Comparison within the Batrachochytrium genus and two closely related non-pathogenic saprophytic chytrids identified variation in sequence and protein domain counts. We further test these new Bd-BRAZIL genomes to assess their utility as reference genomes for transcriptome alignment and analysis. Our analysis examines the genomic variation between strains in Bd-BRAZIL and Bd-GPL and offers insights into the application of these genomes as reference genomes for future studies.
2024-01-31 | GSE253912 | GEO