Biology subjects

Kolasa, M. R.

Publications and source records attributed to Kolasa, M. R..

6 recordsLinked to original sources

bioRxiv2025

Dissecting multitrophic interactions: the relationships among Entomophthora, their dipteran hosts, and associated bacteria

Interactions with microorganisms from across a range of mutualism-to-pathogenicity spectrums shape the biology of insects at all levels - from individual traits to populations and communities. However, the understanding of pathogens attacking non-model insect species in natural ecosystems, or their interactions with other insect-associated microorganisms, is fragmentary. Here, we tested a conceptually novel approach - the simultaneous sequencing of insect, fungal, and bacterial marker gene amplicons - as a means of dissecting interactions among entomopathogenic fungi in the genus Entomophthora and their dipteran hosts in South Greenland. We aimed to describe the taxonomic diversity of Entomophthora-killed flies, their pathogens, and the bacterial diversity within a set of field-collected dead insects exhibiting signs of Entomophthora infection. Across nine collected dipteran species, we identified multiple Entomophthora genotypes, with strong but not perfect patterns of host-specificity across the five targeted marker regions. Additionally, we found consistent differences in bacterial community composition among fungus-killed fly species and sampling sites. Our results substantially expand the knowledge of Entomopthora diversity and host associations while providing the very first insights into associated bacteria and their potential roles. We also conclude that multi-target amplicon sequencing can be a powerful tool for addressing broad questions about biological interactions in diverse natural communities.

ecology↗

bioRxiv2024

Peasants at the queen's table?: The microbiome's dynamics throughout swarming preparation in honey bees (Apis mellifera)

The intricate relationship between hosts and bacterial symbionts was crucial for the evolution of multiple insect clades. Western honey bees (Apis mellifera) have distinctive and highly stable microbiomes in terms of bacterial taxonomic composition. However, despite the significant development of molecular techniques observed in recent decades, we still are far from understanding much about the dynamics of honey bees microbiomes in terms of their strain diversity and quantities. The overall stable composition of their microbiome and complex behavior make honey bees a perfect model species for studying the gut-brain axis, where the gut microbiome can efficiently influence the hosts behavior. Here, by implementing high-throughput amplicon sequencing of bacterial 16S rRNA V4 and V1V2 hypervariable regions alongside a cutting-edge quantification approach, we aimed to describe the dynamic in honey bee young workers microbiome composition and quantity throughout swarming preparation. Our results show no changes in microbial absolute abundances throughout the swarming preparation among young worker bees. The V4 and V1V2 datasets congruently reconstructed microbial composition with some notable exceptions, and differential abundance analysis indicated that Bombella and Bartonella significantly changed over batches.

evolutionary biology↗

bioRxiv2024

A new tool in a toolbox: Addressing challenges in high-throughput microbiota surveys across diverse wild insects

With their significant effects on the biology of higher organisms, host-associated microbiota has attracted the research communitys attention. The rapid progress in sequencing techniques has greatly facilitated microbial community characterization. However, the most popular surveying technique, marker gene amplicon sequencing, has multiple caveats that are not often addressed satisfactorily, including the uncertainty about the identity of the surveyed wild-caught specimens, variable and sometimes very low abundance of microbes in some samples, or reagent- and cross-contamination. As a result, researchers often obtain incomplete, biased, and sometimes totally incorrect microbial community profiles. Here, we present a versatile, cost-effective, and high-throughput quantitative multi-target amplicon sequencing workflow for the characterization of host-associated microbial communities, combining laboratory and bioinformatic steps and addressing most of the known methodological issues. Optimized for the study of the microbiota of wild insects, it can be easily adapted for other sample types. Outputs include contamination-controlled data on the absolute abundance and identity of microbes present in insect samples, both at genotype- and OTU-level, as well as host barcodes alongside information on parasite infections. Using 1384 samples from Zackenberg Valley, NE Greenland, we demonstrate the potential of the workflow to study insect and symbiont diversity patterns across a large portion of a diverse natural community.

ecology↗

bioRxiv2024

Implementing high-throughput insect barcoding in microbiome studies: impact of non-destructive DNA extraction on microbiome reconstruction

BackgroundSymbiotic relationships with diverse microorganisms are crucial for many aspects of insect biology. However, while our understanding of insect taxonomic diversity and the distribution of insect species in natural communities is limited, we know much less about their microbiota. In the era of rapid biodiversity declines, as researchers increasingly turn towards DNA-based monitoring, developing and broadly implementing approaches for high-throughput and cost-effective characterization of both insect and insect-associated microbial diversity is essential. We need to verify whether approaches such as high-throughput barcoding, a powerful tool for identifying wild insects, would permit subsequent microbiota reconstruction in these specimens. MethodsHigh-throughput barcoding ("megabarcoding") methods often rely on non-destructive approaches for obtaining template DNA for PCR amplification by leaching DNA out of insect specimens using alkaline buffers such as HotSHOT. This study investigated the impact of HotSHOT on microbial abundance estimates and the reconstructed bacterial community profiles. We addressed this question by comparing quantitative 16S rRNA amplicon sequencing data for HotSHOT-treated or untreated specimens of 16 insect species representing six orders and selected based on the expectation of limited variation among individuals. ResultsWe find that in 13 species, the treatment significantly reduced microbial abundance estimates, corresponding to an estimated 15-fold decrease in amplifiable 16S rRNA template on average. On the other hand, HotSHOT pre-treatment had a limited effect on microbial community composition. The reconstructed presence of abundant bacteria with known significant effects was not affected. On the other hand, we observed changes in the presence of low-abundance microbes, those close to the reliable detection threshold. Alpha and beta diversity analyses showed compositional differences in only a few species. ConclusionOur results indicate that HotSHOT pre-treated specimens remain suitable for microbial community composition reconstruction, even if abundance may be hard to estimate. These results indicate that we can cost-effectively combine barcoding with the study of microbiota across wild insect communities. Thus, the voucher specimens obtained using megabarcoding studies targeted at characterizing insect communities can be used for microbiome characterizations. This can substantially aid in speeding up the accumulation of knowledge on the microbiomes of abundant and hyperdiverse insect species.

microbiology↗

bioRxiv2024

Limited variation in microbial communities across populations of Macrosteles leafhoppers (Hemiptera: Cicadellidae)

Microbial symbionts play important roles in insect biology, but their diversity, distribution, and dynamics over time across host populations are poorly understood. We surveyed the spatio-temporal distribution of bacterial symbionts in the broadly distributed and economically significant leafhopper genus Macrosteles, with emphasis on Macrosteles laevis, using host and symbiont marker gene amplicon sequencing. The cytochrome oxidase I (COI) gene data revealed no strong genetic differentiation across M. laevis populations, significant levels of heteroplasmy, and multiple cases of parasitoid infections. 16S rRNA data confirmed the universal presence of the ancient nutritional endosymbionts Sulcia and Nasuia and a high prevalence of Arsenophonus. Interestingly, in contrast to most previously surveyed species, in M. laevis we found only occasional cases of infection with facultative endosymbionts and other bacteria. There was no significant variation in symbiont prevalence across populations, or among sampling years for the same population. Facultative endosymbionts including Rickettsia, Wolbachia, Cardinium, and Lariskella, were more common in other Macrosteles species. Combined, our data demonstrate that not all species show clear spatial and temporal variation in genetic structure and microbial prevalence. However, simultaneous characterization of host and symbiont marker gene amplicons in large insect collections can help understand the dynamics of host-microbe interactions.

evolutionary biology↗

bioRxiv2022

Till evolution do us part: The diversity of symbiotic associations across populations of Philaenus spittlebugs

Symbiotic bacteria have played crucial roles in the evolution of sap-feeding insects and can strongly affect host function. However, their diversity and distribution within species are not well understood; we dont know to what extent environmental factors or associations with other species may affect microbial community profiles. Here, we sequenced host and bacterial marker gene amplicons to survey the bacterial community composition across multiple populations of Philaenus spittlebugs. Host mitochondrial sequence data confirmed morphology-based identification of 6 species and revealed two divergent clades of Philaenus spumarius. All of them hosted the primary symbiont Sulcia that was almost always accompanied by Sodalis. Interestingly, populations and individuals often differed in the presence of Sodalis sequence variants, suggestive of intra-genome 16S rRNA variant polymorphism combined with rapid genome evolution and/or recent additional infections or replacements of the co-primary symbiont. The prevalence of facultative endosymbionts, including Wolbachia, Rickettsia, and Spiroplasma, varied among populations. Notably, COI amplicon data also showed that nearly a quarter of P. spumarius were infected by parasitoid flies (Verralia aucta). One of the Wolbachia OTUs was exclusively present in Verralia-parasitized specimens, suggestive of parasitoids as their source and highlighting the utility of host gene amplicon sequencing in microbiome studies.

ecology↗