Biology subjects

Borovicka, J.

Publications and source records attributed to Borovicka, J..

5 recordsLinked to original sources

bioRxiv2026

The one that abstained: Psilocybe fuscofulva genome suggests two recent origins of the psilocybin gene cluster in Psilocybe

Production of the psychoactive compound psilocybin is a defining feature of the genus Psilocybe, commonly referred to as "psychedelic mushrooms". However, Psilocybe fuscofulva is a striking exception within Psilocybe sensu stricto as it lacks the stereotypical blue bruising characteristic of the genus, and psilocybin has not been detected in the species.To investigate the evolutionary events leading to differential psilocybin production among Psilocybe species, we produced genome assemblies two P. fuscofulva strains, one Psilocybe polytrichoides strain, and one Psilocybe tampanensis strain, complemented by reannotated public genomes and metagenome-derived assemblies from fungarium specimens. This sample represents both major Psilocybe clades (Clade I and Clade II) and the most closely related genera. Phylogenomic analysis based on 100 single-copy orthologs curated for high branch support strongly placed P. fuscofulva as the earliest-diverging lineage in Psilocybe Clade I. No psilocybin gene cluster (PGC) homologs, whether clustered or dispersed, were identified in P. fuscofulva, whereas a single intact PGC was present in all other examined Psilocybe genomes. The PGC resides in two distinct, clade-specific genomic loci: one conserved in Clade I and another in Clade II, each displaying characteristic gene orders and orientations consistent with rearrangement through circular intermediates. Time-calibrated phylogenies estimated the Psilocybe crown group at approximately 28 million years ago, with major clade divergences occurring in the Miocene. The absence of the PGC in P. fuscofulva, together with clade-specific structural conservation and the lack of remnant sequences at alternate loci, supports two independent origins of the PGC within Psilocybe: one in the ancestor of Clade II and a subsequent origin in Clade I following divergence from P. fuscofulva, most likely via horizontal gene transfer (HGT). Gene phylogenies provide weak support for transfer from Clade I to Clade II, although broader sampling is required for confirmation. These results constrain the timeframe of PGC emergence and dispersal to the Miocene, implying rapid HGT events possibly driven by ecological pressures in expanding grassland ecosystems. This study challenges the assumption of an ancestral psilocybin pathway in Psilocybe and its close relatives and underscores multiple recent acquisitions of the PGC that suggest it is an ecologically important metabolic trait in psychoactive fungi.

evolutionary biology↗

bioRxiv2025

Neuronal Silencing and Protection in a Mouse Model of Demyelination

Damage to the myelin sheath that protects axons in the central nervous system is a hallmark pathology of demyelinating diseases like multiple sclerosis. Cuprizone-induced demyelination in mice is a common model for studying demyelination and remyelination. However, the relationship between myelin damage and recovery and neuronal function remains poorly understood. By monitoring hippocampal myelination and neuronal activity in the same mice, we assessed longitudinal changes following cuprizone consumption and remyelination treatment. Upon cuprizone consumption, a rapid decline in neuronal activity preceded slower demyelination. Female mice showed a more intense early decrease in brain activity and a stronger correlation with levels of myelin loss. Remyelination treatment led to increased myelination levels and recovery of neuronal activity compared to vehicle treatment. Changes in single-neuron firing rates during treatment were proportional to the pre-cuprizone firing rate in the same cells, highlighting a potential linkage between the status of myelin recovery and cellular activity.

neuroscience↗

bioRxiv2024

Systemic exposure to COVID-19 virus-like particles modulates firing patterns of cortical neurons in the living mouse brain

Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) causes a systemic infection that affects the central nervous system. We used virus-like particles (VLPs) to explore how exposure to the SARS-CoV-2 proteins affects brain activity patterns in wild-type (WT) mice and in mice that express the wild-type human tau protein (htau mice). VLP exposure elicited dose-dependent changes in corticosterone and distinct chemokine levels. Longitudinal two-photon microscopy recordings of primary somatosensory and motor cortex neurons that express the jGCaMP7s calcium sensor tracked modifications of neuronal activity patterns following exposure to VLPs. There was a substantial short-term increase in stimulus-evoked activity metrics in both WT and htau VLP-injected mice, while htau mice showed also increased spontaneous activity metrics and increase activity in the vehicle-injected group. Over the following weeks, activity metrics in WT mice subsided, but remained above baseline levels. For htau mice, activity metrics either remain elevated or decreased to lower levels than baseline. Overall, our data suggest that exposure to the SARS-CoV-2 VLPs leads to strong short-term disruption of cortical activity patterns in mice with long-term residual effects. The htau mice, which have a more vulnerable genetic background, exhibited more severe pathobiology that may lead to more adverse outcomes.

neuroscience↗

bioRxiv2024

Variation of carbon, nitrogen and phosphorus content in fungi reflects their ecology and phylogeny

Fungi are an integral part of the nitrogen and phosphorus cycling in trophic networks, as they participate in biomass decomposition and facilitate plant nutrition through root symbioses. Nutrient content varies considerably between the main fungal habitats, such as soil, plant litter or decomposing dead wood, but there are also large differences within habitats. While some soils are heavily loaded with N, others are limited by N or P. One way in which nutrient availability can be reflected in fungi is their content in biomass. In this study, we determined the C, N, and P content (in dry mass) of sporocarps of 214 fungal species to inspect how phylogeny and membership in ecological guilds (soil saprotrophs, wood saprotrophs, and ectomycorrhizal fungi) affect the nutrient content of fungal biomass. The C content of sporocarps (415 {+/-} 25 mg g-1) showed little variation (324-494 mg g-1), while the range of N (46 {+/-} 20 mg g-1) and P (5.5 {+/-} 3.0 mg g-1) contents was within one order of magnitude (8-103 mg g-1 and 1.0-18.9 mg g-1, respectively). Importantly, the N and P contents were significantly higher in the biomass of soil saprotrophic fungi compared to wood saprotrophic and ectomycorrhizal fungi. While the average C/N ratio in fungal biomass was 11.2, values exceeding 40 were recorded for some fungi living on dead wood, typically characterized by low N content. The N and P content of fungal mycelium also showed a significant phylogenetic signal, with differences in nutrient content being relatively low within species and genera of fungi. A strong correlation was found between N and P content in fungal biomass, while the correlation of N content and the N-containing fungal cell wall biopolymer - chitin showed only weak significance. The content of macronutrients in fungal biomass is influenced by the fungal life style and nutrient availability and is also limited by phylogeny.

microbiology↗

bioRxiv2022

Recording large-scale, cellular-resolution neuronal activity from freely-moving mice

Current methods for recording large-scale neuronal activity from behaving mice with single-cell resolution require either fixing the mouse head under a microscope or attachment of a recording device to the animals skull. Both of these options significantly affect the animal behavior and hence also the recorded brain activity patterns. Here, we introduce a new method to acquire snapshots of single-cell cortical activity maps from freely-moving mice using a calcium sensor called CaMPARI. CaMPARI has a unique property of irreversibly changing its color from green to red inside active neurons when illuminated with 400nm light. We capitalize on this property to demonstrate cortex-wide activity recording without any head fixation or attachment of a miniaturized device to the mouses head. Multiple cortical regions were recorded while the mouse was performing a battery of behavioral and cognitive tests. We identified task-dependent activity patterns across motor and somatosensory cortices, with significant differences across sub-regions of the motor cortex. This new CaMPARI-based recording method expands the capabilities of recording neuronal activity from freely-moving and behaving mice under minimally-restrictive experimental conditions and provides large-scale volumetric data that are not accessible otherwise.

neuroscience↗