Biology subjects

Csernetics, A.

Publications and source records attributed to Csernetics, A..

6 recordsLinked to original sources

bioRxiv2026

Interaction Patterns of Mucormycotina Fungi with Professional Phagocytes and Amoebae: A Comparative Phylogenetic and Geographic Survey on Clinical and Environmental Species

Mucormycosis is among the most lethal fungal infections in clinical medicine, with crude mortality rates between 50 and 90% that have improved little over decades of antifungal development. Alveolar macrophages constitute the primary cellular defense against inhaled Mucorales spores, yet quantitative comparative data on phagocytic outcomes across the taxonomic breadth of this fungal order are absent from the literature. We co-incubated 62 Mucorales strains drawn from nine phylogenetic groups and 12 countries with MH-S murine alveolar macrophages and with Dictyostelium discoideum amoeba, at multiplicities of infection (MOI) of 1 and 5 and at incubation times of 1.5 and 3 hours. Automated phagocytic index quantification was combined with spore morphometric measurements and geographic metadata. Macrophage phagocytic indices differed highly significantly among the nine phylogenetic groups across all experimental conditions (Kruskal-Wallis H = 394-780; p = 10^-163 to 10^-74). Group 1 (Absidia and Cunninghamella species) showed the lowest phagocytic index; Groups 5 (Rhizopus arrhizus) and 6 (Gilbertella persicaria and Mycotypha species) showed the highest. Larger spore area correlated negatively with macrophage phagocytic index. In the central comparative finding, Spearman rank correlations between macrophage and D. discoideum phagocytic indices were near zero across all four conditions (r = -0.07 to +0.11; all p > 0.8), demonstrating that protozoan phagocytosis does not predict the mammalian macrophage phagocytic hierarchy. Kinetic analysis further revealed, for the first time in any Mucorales or Mucormycotina species, evidence of vomocytosis in MH-S macrophages challenged with Group 8 (Mucor clade II) spores at MOI 1, and in D. discoideum across four groups at MOI 5 after 3 hours. These findings establish a quantitative, phylogenetically resolved framework for Mucorales innate immune recognition, demonstrate that the evolutionary training ground hypothesis does not hold at the order level for Mucorales, and identify vomocytosis as a previously unrecognised immune evasion mechanism in Mucormycotina.

microbiology↗

bioRxiv2026

Functionally dark genes and the transcriptomic landscape of sporulation in a model mushroom-forming fungus

Spores are the primary means of fungal reproduction, contributing to genetic diversity, colonization, and adaptation. Although spore formation is a pivotal part of the fungal life cycle, its genetic underpinnings remain poorly known. In this study, we characterize transcriptomic changes from late meiosis to early basidiospore formation in the mushroom-forming fungus Coprinopsis cinerea, decipher several cellular processes, and identify novel genes involved in this process. We identify distinct trajectories of gene expression, each of which display different functional signals, corresponding to meiotic and morphogenetic processes and transitions between these. Our analyses identify diverse arrays of fungal cell wall modifying carbohydrate-active enzymes, ferritins, a putative catechol-melanin synthesis pathway, as well as components of the mitotic/meiotic apparatus. We present twelve highly conserved genes with roles specific to sexual sporulation in both budding yeast and C. cinerea, indicating deep conservation of the gene networks driving sexual spore formation. Reverse genetics identified three conserved but functionally poorly characterized genes conferring sporeless and spore-poor phenotypes that result from postmeiotic developmental arrests stemming from spore inflation and nuclear migration problems. Overall, this study provides novel insight into basidiomycete spore formation and highlights the cornucopia of novel functions encoded by functionally dark genes.

microbiology↗

bioRxiv2024

A new regulator of sporulation sheds light on spore morphogenesis and ballistospory in mushroom-forming fungi

Sporulation is the most widespread means of reproduction and dispersal in fungi. In the Basidiomycota, sexual spores are produced on specialised cells known as basidia, from which they are discharged forcibly by a powered process called ballistospory, the highest known acceleration in nature. However, the genetics of sporulation, in particular postmeiotic events related to spore morphogenesis and ballistospory, remain poorly known. Here, we explore the genetics of these processes, based on a new, highly conserved transcription factor, Sporulation-Related Regulator 1 (SRR1), and its putative downstream regulatory network. Reverse genetics of Srr1 in the model mushroom Coprinopsis cinerea and commercially produced oyster mushroom indicated a conserved role of Srr1 in sporulation across Agaricomycetes. RNA-Seq analysis and motif-based inference of a hypothetical SRR1 gene regulatory network allowed delimiting putative targets regulated by SRR1 in a direct and indirect manner. Using this network and comparative genomics, we identified genes associated with ballistospory, including a putative SRR1-target chitinase, which was found to be required for normal spore production and morphology. Overall, our study offers new insights into the genetic mechanisms governing postmeiotic spore morphogenesis and ballistospory in the Agaricomycetes.

microbiology↗

bioRxiv2023

Snowball: a novel gene family required for developmental patterning in fruiting bodies of mushroom-forming fungi (Agaricomycetes)

The morphogenesis of sexual fruiting bodies of fungi is a complex process determined by a genetically encoded program. Fruiting bodies reached the highest complexity levels in the Agaricomycetes, yet, the underlying genetics is currently poorly known. In this work, we functionally characterized a highly conserved unannotated gene termed snb1, whose expression level increases rapidly during fruiting body initiation. According to phylogenetic analyses, orthologues of snb1 are present in almost all agaricomycetes and may represent a novel conserved gene family that plays a substantial role in fruiting body development. We disrupted snb1 using CRISPR/Cas9 in the agaricomycete model organism Coprinopsis cinerea. Snb1 deletion mutants formed unique, snowball-shaped, rudimentary fruiting bodies that could not differentiate caps, stipes and lamellae. We took advantage of this phenotype to study fruiting body differentiation using RNA-Seq analyses. This revealed differentially regulated genes and gene families that, based on wild-type RNA-Seq data, were upregulated early during development and showed tissue-specific expression, underscoring their potential role in differentiation. Taken together, the novel gene family of snb1 and the differentially expressed genes in the snb1 mutants provide valuable insights into the complex mechanisms underlying developmental patterning in the Agaricomycetes. ImportanceFruiting bodies of mushroom-forming fungi (Agaricomycetes) are complex multicellular structures, with a spatially and temporally integrated developmental program that is, however, currently poorly known. In this study we present a novel, conserved gene family, Snowball (snb), termed after the unique, differentiation-less fruiting body morphology of snb1 knockout strains in the model mushroom Coprinopsis cinerea. Snb is a hitherto unannotated gene that is highly conserved among agaricomycetes and encodes a protein of unknown function. A comparative transcriptomic analysis of the early developmental stages of differentiated wild-type and non-differentiated mutant fruiting bodies revealed conserved differentially expressed genes which may be related to tissue differentiation and developmental patterning fruiting body development.

developmental biology↗

bioRxiv2022

Pre-assembled Cas9 ribonucleoprotein-mediated gene deletion identifies the carbon catabolite repressor and its target genes in Coprinopsis cinerea

Cre1 is an important transcription factor that regulates carbon catabolite repression (CCR) and is widely conserved across fungi. This gene has been extensively studied in several Ascomycota species, whereas its role in gene expression regulation in the Basidiomycota remains poorly understood. Here, we identified and investigated the role of cre1 in Coprinopsis cinerea, a basidiomycete model mushroom that can efficiently degrade lignocellulosic plant wastes. We used a rapid and efficient gene deletion approach based on PCR-amplified split-marker DNA cassettes together with in-vitro assembled Cas9-guide RNA ribonucleoproteins (Cas9-RNPs) to generate C. cinerea cre1 gene deletion strains. Gene expression profiling of two independent C. cinerea cre1 mutants showed significant deregulation of carbohydrate metabolism, plant cell wall degrading enzymes (PCWDEs), plasma membrane transporter-related and several transcription factor encoding genes, among others. Our results support the notion that, similarly to reports in the ascomycetes, Cre1 of C. cinerea orchestrates CCR through a combined regulation of diverse genes, including PCWDEs, transcription factors that positively regulate PCWDEs and membrane transporters which could import simple sugars that can induce the expression of PWCDEs. Somewhat paradoxically, though in accordance with other Agaricomycetes, genes related to lignin degradation were mostly downregulated in cre1 mutants, indicating they fall under different regulation than other PCWDEs. The gene deletion approach and the data presented in this paper expand our knowledge of CCR in the Basidiomycota and provide functional hypotheses on genes related to plant biomass degradation. ImportanceMushroom-forming fungi include some of the most efficient degraders of lignocellulosic plant biomass. They degrade dead plant materials by a battery of lignin-, cellulose-, hemicellulose- and pectin-degrading enzymes, the encoding genes of which are under tight transcriptional control. One of the highest-level regulation of these metabolic enzymes is known as carbon catabolite repression, which is orchestrates by the transcription factor Cre1, and ensures that costly lignocellulose-degrading enzyme genes are expressed only when simple carbon sources (e.g. glucose) are not available. Here, we identified the Cre1 ortholog in a litter-decomposer Agaricomycete, Coprinopsis cinerea, knocked it out and characterized transcriptional changes in the mutants. We identified several dozen lignocellulolytic enzyme genes as well as membrane transporters and other transcription factors as putative target genes. These results extend knowledge on carbon catabolite repression to litter decomposer Basidiomycota.

microbiology↗

bioRxiv2021

Lessons on fruiting body morphogenesis from genomes and transcriptomes of Agaricomycetes

Fruiting bodies of mushroom-forming fungi (Agaricomycetes) are among the most complex structures produced by fungi. Unlike vegetative hyphae, fruiting bodies grow determinately and follow a genetically encoded developmental program that orchestrates tissue differentiation, growth and sexual sporulation. In spite of more than a century of research, our understanding of the molecular details of fruiting body morphogenesis is limited and a general synthesis on the genetics of this complex process is lacking. In this paper, we aim to comprehensively identify conserved genes related to fruiting body morphogenesis and distill novel functional hypotheses for functionally poorly characterized genes. As a result of this analysis, we report 921 conserved developmentally expressed gene families, only a few dozens of which have previously been reported in fruiting body development. Based on literature data, conserved expression patterns and functional annotations, we provide informed hypotheses on the potential role of these gene families in fruiting body development, yielding the most complete description of molecular processes in fruiting body morphogenesis to date. We discuss genes related to the initiation of fruiting, differentiation, growth, cell surface and cell wall, defense, transcriptional regulation as well as signal transduction. Based on these data we derive a general model of fruiting body development, which includes an early, proliferative phase that is mostly concerned with laying out the mushroom body plan (via cell division and differentiation), and a second phase of growth via cell expansion as well as meiotic events and sporulation. Altogether, our discussions cover 1480 genes of Coprinopsis cinerea, and their orthologs in Agaricus bisporus, Cyclocybe aegerita, Armillaria ostoyae, Auriculariopsis ampla, Laccaria bicolor, Lentinula edodes, Lentinus tigrinus, Mycena kentingensis, Phanerochaete chrysosporium, Pleurotus ostreatus, and Schizophyllum commune, providing functional hypotheses for [~]10% of genes in the genomes of these species. Although experimental evidence for the role of these genes will need to be established in the future, our data provide a roadmap for guiding functional analyses of fruiting related genes in the Agaricomycetes. We anticipate that the gene compendium presented here, combined with developments in functional genomics approaches will contribute to uncovering the genetic bases of one of the most spectacular multicellular developmental processes in fungi.

evolutionary biology↗