Biology subjects

Kolasa, M.

Publications and source records attributed to Kolasa, M..

5 recordsLinked to original sources

bioRxiv2026

Whole forest in a pouch? Methods converge in uncovering wood ants fungal and bacterial microbiota

Despite their importance for individual fitness and population processes, the microbiota of many ecologically significant insects remains poorly explored. Even less is known about the interactions between microbial communities inhabiting insects and their surrounding environment. Ant infrabuccal pockets (IBPs), representing the interface between the digestive tract and the external environment, provide an opportunity to study these interactions. Here, we aimed to characterize ant-microbial interaction networks in the forest floor by profiling fungal and bacterial communities associated with the IBP of Formica polyctena ants, known as ecosystem engineers in temperate forests. We used direct microscopy, culturing, and sequencing amplicons of ITS1, ITS2, 18S rRNA marker regions to describe fungal communities, and 16S rRNA metabarcoding to characterize bacterial communities. Classical methods combined with a multi-marker amplicon sequencing allowed for a comprehensive description of the IBP microbiota. Fungal communities consistently contained representatives of 15 ecologically diverse genera, including insect-associated yeasts and primarily saprotrophic or endophytic fungi. Bacterial communities were dominated by genera previously reported from ant guts, mainly Bacilli and Alphaproteobacteria, and showed greater stability among ant colonies than fungal communities. Further studies on red wood ants IBP microbiota would enhance our understanding of their role in shaping ecological networks in forest ecosystems.

ecology↗

bioRxiv2025

Deletion of Murine Endothelial Bag3 Alters the Cellular Proteome Among Organs of Origin

BAG3 (Bcl-2 associated athanogene 3) is a multifunctional protein with pleiotropic effects in multiple cell types. Despite our knowledge of its role in cardiovascular disease, its specific role in endothelial cells (ECs) is unknown. The purpose of this study was to identify differences in the EC proteome of multiple tissues before and after cell specific deletion of Bag3. We hypothesized that BAG3 loss would uniquely alter the baseline proteome landscape of ECs in each tissue. Cdh5(PAC)-CreERT2;Bag3f/f mice received tamoxifen (KO; n=18) or vehicle (WT; n=18) and tissues (brain, heart, lung, and peripheral skeletal muscle-skm) were collected for FACS sorting of ECs from equal numbers of male and female mice at >22 weeks of age, followed by LC-MS/MS label-free proteomics. Initial comparisons of the WT proteomes between tissues revealed differential abundance of EC proteins (p<0.05), including: 379 brain v heart; 325 brain v lung; 501 brain v skm; 354 heart v lung; 107 heart v skm; and 442 lung v skm. Additionally, the EC mitochondrial proteome was unique to each tissue of origin, with significantly (p<0.05) higher proportions dedicated to complexes I, III, IV and V, in heart compared to the other tissues. KO demonstrated the largest effect on skm ECs, increasing 30 proteins (Mybpc2 L2FC=4.81; PFKM L2FC=3.02) and decreasing 65 (CDC42 L2FC=-2.44; Prpf8 L2FC=-2.24). Overall, these results demonstrate that the EC proteome of different tissues is unique and that the loss of BAG3 in these cells differentially alters a small proportion of the EC specific proteome.

physiology↗

bioRxiv2024

Cold and lonely: low-abundance microbiota and no core microbiome across a broad geographic sampling of a mosquito species in Greenland

Microbial symbionts are key players in insect ecology and evolution, but microbiota vary widely across and within host species. The microbiota of insect clades such as high-latitude mosquitoes remain understudied, despite their abundance and potential economic and medical relevance. Here, we resolve temporal and spatial variation in the abundance and diversity of bacteria and fungi associated with Ochlerotatus mosquitoes in Greenland. To this aim, we apply a comprehensive workflow combining the simultaneous characterization of host, bacterial, and fungal marker regions, contamination filtering, as well as bacterial quantification and joint species distribution modelling. We find that 573 mosquitoes collected in five regions of Greenland between 2009 and 2024 represented two species (O. nigripes and O. impiger). Their microbial communities were low-abundance, highly diverse, and dominated by environmentally versatile taxa, showing high individual-to-individual-rather than spatio-temporal variation, although taxa such as Pseudomonas and Serratia exhibited sex-specific associations. DNA from local vertebrates and potential vertebrate pathogens (e.g., Bartonella) was detected, likely reflecting blood meals. These findings suggest that Greenland Ochlerotatus mosquitoes do not rely on core microbiota, but engage in flexible associations with diverse, low-abundance microbial communities. They also point to mosquitoes as likely vectors of bacterial and fungal pathogens in the Arctic.

ecology↗

bioRxiv2024

What lurks beneath the humped back? - The patterns of bacterial abundance, diversity and distribution across communities of a dipteran family

Symbiotic microorganisms can profoundly impact insects, their life history traits, population dynamics, and evolutionary trajectories. However, microbiota remain poorly understood in natural insect communities, especially in dark taxa - i.e., hyperdiverse, yet understudied clades. Here, we implemented a novel multi-target amplicon sequencing approach to study microbiota in complex, species-rich communities. It combines four methodological innovations: (1) To establish a host taxonomic framework, we sequenced amplicons of the host marker gene (COI) and reconstructed barcodes alongside microbiota characterisation. (2) To assess microbiota abundance, we incorporated spike-in-based quantification. (3) To improve the phylogenetic resolution for the dominant endosymbiont, Wolbachia, we analysed bycatch data from the COI amplicon sequencing. (4) To investigate the primary drivers of host-microbe associations in massive multi-dimensional datasets, we performed HMSC modelling. Applying this approach to 1,842 wild-caught scuttle flies (Diptera: Phoridae) from northern Sweden, we organised them into 480 genotypes and 186 species and gained unprecedented insights into their microbiota. We found orders-of-magnitude differences in bacterial abundance and massive within-population variation in microbiota composition. Patterns and drivers differed among microbial functional categories: the distribution and abundance of facultative endosymbionts (Wolbachia, Rickettsia, Spiroplasma) were shaped by host species, genotype and sex. In contrast, many other bacterial taxa were broadly distributed across species and sites. This study highlights facultative endosymbionts as key players in insect microbiota and reveals striking variations in distributional patterns of microbial clades. It also demonstrates the power of integrative sequencing approaches in uncovering the ecological complexity and significance of symbiotic microorganisms in multi-species natural communities.

ecology↗

bioRxiv2019

The role of genetic diversity in the evolution and maintenance of environmentally-cued, male alternative reproductive tactics

BackgroundAlternative reproductive tactics (ARTs) are taxonomically pervasive strategies adopted by individuals to maximize reproductive success within populations. Even for conditionally-dependent traits, consensus postulates most ARTs involve both genetic and environmental interactions (GEIs), but to date, quantifying genetic variation underlying the threshold disposing an individual to switch phenotypes in response to an environmental cue has been a difficult undertaking. Our study aims to investigate the origins and maintenance of ARTs within environmentally disparate populations of the microscopic bulb mite, Rhizoglyphus robini, that express fighter and scrambler male morphs mediated by a complex combination of environmental and genetic factors. ResultsUsing never-before-published individual genetic profiling, we found all individuals across populations are highly inbred with the exception of scrambler males in stressed environments. In fact within the poor environment, scrambler males and females showed no significant difference in genetic differentiation (Fst) compared to all other comparisons, and although fighters were highly divergent from the rest of the population in both poor or rich environments (e.g., Fst, STRUCTURE), fighters demonstrated approximately three times less genetic divergence from the population in poor environments. AMOVA analyses further corroborated significant genetic differentiation across subpopulations, between morphs and sexes, and among subpopulations within each environment. ConclusionOur study provides new insights into the origin of ARTs in the bulb mite, highlighting the importance of GEIs: genetic correlations, epistatic interactions, and sex-specific inbreeding depression across environmental stressors. Asymmetric reproductive output, coupled with the purging of highly inbred individuals during environmental oscillations, also facilitates genetic variation within populations, despite evidence for strong directional selection. This cryptic genetic variation also conceivably facilitates stable population persistence even in the face of spatially or temporally unstable environmental challenges. Ultimately, understanding the genetic context that maintains thresholds, even for conditionally-dependent ARTs, will enhance our understanding of within population variation and our ability to predict responses to selection.

evolutionary biology↗