Project description:We analyzed gene expression in the American black bear, Ursus americanus, using a custom 12,800 cDNA probe (BA02) microarray to detect differences in expression that occur in heart and liver during winter hibernation in comparison to summer active animals. We identified 245 genes in heart and 319 genes in liver that were differentially expressed between winter and summer. The expression of 24 genes was significantly elevated during hibernation in both heart and liver. These genes are mostly involved in lipid catabolism and protein biosynthesis and include RNA binding protein motif 3 (Rbm3), which enhances protein synthesis at mildly hypothermic temperatures. Elevated expression of protein biosynthesis genes suggests induction of translation that may be related to adaptive mechanisms reducing cardiac and muscle atrophies over extended periods of low metabolism and immobility during hibernation in bears. Coordinated reduction of transcription of genes involved in amino acid catabolism suggests redirection of amino acids from catabolic pathways to protein biosynthesis. We identify common for black bears and small mammalian hibernators transcriptional changes in the liver that include induction of genes responsible for fatty acid β oxidation and carbohydrate synthesis and depression of genes involved in lipid biosynthesis, carbohydrate catabolism, cellular respiration and detoxification pathways. Our findings show that modulation of gene expression during winter hibernation represents molecular mechanism of adaptation to extreme environments. Black bears sampled during winter hibernation were compared with the animals sampled during summer. Two tissue types, liver and heart, were hybridized on a custom 12,800 cDNA probe nylon membrane microarray platform . Six hibernating and five summer active bears were studied in experiments with liver tissue, six hibernating and five summer active animals were tested with heart tissue.
Project description:We analyzed gene expression in the American black bear, Ursus americanus, using a custom 12,800 cDNA probe (BA02) microarray to detect differences in expression that occur in heart and liver during winter hibernation in comparison to summer active animals. We identified 245 genes in heart and 319 genes in liver that were differentially expressed between winter and summer. The expression of 24 genes was significantly elevated during hibernation in both heart and liver. These genes are mostly involved in lipid catabolism and protein biosynthesis and include RNA binding protein motif 3 (Rbm3), which enhances protein synthesis at mildly hypothermic temperatures. Elevated expression of protein biosynthesis genes suggests induction of translation that may be related to adaptive mechanisms reducing cardiac and muscle atrophies over extended periods of low metabolism and immobility during hibernation in bears. Coordinated reduction of transcription of genes involved in amino acid catabolism suggests redirection of amino acids from catabolic pathways to protein biosynthesis. We identify common for black bears and small mammalian hibernators transcriptional changes in the liver that include induction of genes responsible for fatty acid β oxidation and carbohydrate synthesis and depression of genes involved in lipid biosynthesis, carbohydrate catabolism, cellular respiration and detoxification pathways. Our findings show that modulation of gene expression during winter hibernation represents molecular mechanism of adaptation to extreme environments.
Project description:The class Dothideomycetes (along with Eurotiomycetes) includes numerous rock-inhabiting fungi (RIF), a group of ascomycetes that tolerates surprisingly well harsh conditions prevailing on rock surfaces. Despite their convergent morphology and physiology, RIF are phylogenetically highly diverse in Dothideomycetes. However, the positions of main groups of RIF in this class remain unclear due to the lack of a strong phylogenetic framework. Moreover, connections between rock-dwelling habit and other lifestyles found in Dothideomycetes such as plant pathogens, saprobes and lichen-forming fungi are still unexplored. Based on multigene phylogenetic analyses, we report that RIF belong to Capnodiales (particularly to the family Teratosphaeriaceae s.l.), Dothideales, Pleosporales, and Myriangiales, as well as some uncharacterised groups with affinities to Dothideomycetes. Moreover, one lineage consisting exclusively of RIF proved to be closely related to Arthoniomycetes, the sister class of Dothideomycetes. The broad phylogenetic amplitude of RIF in Dothideomycetes suggests that total species richness in this class remains underestimated. Composition of some RIF-rich lineages suggests that rock surfaces are reservoirs for plant-associated fungi or saprobes, although other data also agree with rocks as a primary substrate for ancient fungal lineages. According to the current sampling, long distance dispersal seems to be common for RIF. Dothideomycetes lineages comprising lichens also include RIF, suggesting a possible link between rock-dwelling habit and lichenisation.
Project description:We analyzed oxidized 5-methylcytosine derivatives 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine in nucleic acids of multicellular fungi Laccaria bicolor and Coprinopsis cinerea which have been used as models to study DNA methylation, developmental processes and symbiotic interactions. All three cytosine derivatives were detected in the genomes of both fungi, and importantly, we discovered 5carC in the RNA fractions, potentially including large non-coding, messenger RNAs and small RNA molecules, indicating gene regulatory functions of 5carC.
Project description:Ergosterol, a pivotal constituent of the fungal cell membrane, plays a crucial role in diverse cellular activities. Fungi inherently regulate ergosterol homeostasis, a process traditionally associated with the control of a major transcription factor, like SREBP, activated in response to ergosterol depletion, regardless of which ergosterol biosynthesis step is affected. Contrary to the established paradigm, our investigation demonstrates that the inhibition of ergosterol biosynthesis at specific steps triggers distinct transcriptional responses in erg genes across fungi, including Neurospora crassa, Aspergillus fumigatus, and Fusarium verticillioides. In N. crassa, the targeted responses are orchestrated by several transcription factors that have undergone functional rewiring. Specifically, ERG24 inhibition by amorolfine activates transcription factors SAH-2 and AtrR, resulting in the upregulation of erg24, erg2, erg25 and erg3. Additionally, ERG11 inhibition by azoles activates transcription factor NcSR, leading to the upregulation of erg11 and erg6. Our findings unveil a novel sophisticated regulation model of sterol biosynthesis in fungi which potentially enhances fungal survival in complex environments, thus providing new insights into sterol homeostasis maintenance and a deeper understanding of drug resistance mechanisms in fungi.
Project description:Powdery mildew (PM) is one of the most important and widespread plant diseases caused by obligate biotrophic Ascomycete fungi in the order of Erysiphales. Monocot PM fungi such as Blumeria graminis f.sp. hordei (Bgh) infectious on barley and B. graminis f.sp. tritici (Bgt) infectious on wheat exhibit high-level of host-specialization. By contrast, many dicot PM fungi display rather broad host ranges. To understand why different PM fungi adopt distinct modes of host-adaption, we sequenced the genomes of four dicot PM strains belonging to Golovinomyces cichoracearum (GcC1, GcM1, GcM3) or Oidium neolycopersici (OnM2) and conducted comparative sequence analyses. PM fungi have highly repetitive genomes that are difficult to perform gene prediction. By combing RNA-seq expression evidence with ab initio gene prediction, we successfully improved the number of predicted genes from 4000 to 6000. By comparing the transcriptional profiling from haustoria with mycelia in OnM2 and GcM3, we found that 86%-96% of the predicted genes are expressed in mycelia and/or haustoria, indicating an efficient expression system of PM fungi. Besides, our results showed that gene regulation mechanisms in haustorial cells maybe under gone a much higher level of diversification between OnM2 and GcM3, since they share only a small proportion (21%) of genes up-regulated in huastoria cells. Notably, a higher proportion of candidate effector genes are selectively up-regulated in haustorial cells, agreeing with their function in suppressing host defense and facilitating nutrient uptake.
Project description:The recent release of a large number of genomes from ectomycorrhizal, orchid mycorrhizal and root endophytic fungi have provided deep insight into fungal lifestyle-associated genomic adaptation. Comparative analyses of symbiotic fungal taxa showed that similar outcomes of interactions in distant related root symbioses are examples of convergent evolution. The order Sebacinales represents a sister group to the Agaricomycetes (Basidiomycota) that is comprised of ectomycorrhizal, ericoid-, orchid- mycorrhizal, root endophytic fungi and saprotrophs (Oberwinkler et al., 2013). Sebacinoid taxa are widely distributed from arctic to temperate to tropical ecosystems and are among the most common and species-rich groups of ECM, OM and endophytic fungi (Tedersoo et al., 2012, Tedersoo et al., 2010, Oberwinkler et al., 2013). The root endophyte Piriformospora indica and the orchid mycorrhizal fungus S. vermifera (MAFF 305830) are non-obligate root symbionts which were shown to be able to interact with many different experimental hosts, including the non-mycorrhizal plant Arabidopsis thaliana. These two fungi display similar colonization strategies in barley and in Arabidopsis and the ability to establish beneficial interactions with different hosts (Deshmukh et al., 2006). Colonization of the roots by P. indica and S. vermifera results in enhanced seed germination and biomass production as well as increased resistance against biotic and abiotic stresses in its experimental hosts, including various members of the Brassicaceae family, barley, Nicotiana attenuata and switchgrass (Ghimire, 2011, Ghimire et al., 2009, Ghimire et al., 2011, Waller et al., 2008, Barazani et al., 2007, Deshmukh et al., 2006). Microarray experiments were performed to identify and characterize conserved sebacinoid genes as key determinants in the Sebacinales symbioses.