Biology subjects

Modeo, L.

Publications and source records attributed to Modeo, L..

6 recordsLinked to original sources

bioRxiv2025

Description of three new predator species of Litostomatea (Alveolata, Ciliophora), including sequencing and annotation of their mitochondrial genomes

Three new species of haptorian ciliates Lacrymaria venatrix sp. nov., Phialina famelica sp. nov., and Chanaea vermicularis sp. nov., recovered from water bodies of Tuscany, Italy, are described according to the standards of the Next Generation Taxonomy, which include morphology, ultrastructure, phylogeny, and associated microbial consortium analysis plus mitochondrial genome sequencing and annotation. Lacrymaria venatrix is a species with a small spindle-shaped trunk, a highly contractile neck that equals the trunk in length at its full extension, and a macronucleus consisting of two nodules; it is mostly similar to L. songi but diverges in the denser ciliature, the closer macronuclear nodules, and the single micronucleus. Phialina famelica has a blunter spindle-shaped trunk with a shallow oral bulge and an elongated macronucleus; it is mostly similar to P. salinarum and P. serranoi, but differs in the freshwater habitat, and by having fewer but denser kineties. Chaenea vermicularis differs from its congenerics by a modest contractility combined with a greater elongation ability, the mucocysts organized into multiple rows forming stripes, and the several hundreds of macronuclear nodules. The 18S rDNA-based phylogenetic analysis supports previous observations of the paraphyly of the genera Lacrymaria and Phialina, that need a deep systematics revision. The genus Chaenea seems not to be challenged, though its position within Haptoria remains not fully clear, and C. vermicularis sp. nov. appears rather divergent from its congeners.

zoology↗

bioRxiv2025

Reprogramming of Osimertinib-Resistant EGFR-mutant NSCLC: The Pyruvate-Acetaldehyde-Acetate Pathway As a Key Driver of Resistance

Osimertinib (Osi) resistance remains a significant challenge in EGFR mutant non-small-cell lung cancer (NSCLC). This study investigates the metabolic reprogramming associated with Osi resistance, identifying key metabolic vulnerabilities that may be targeted for therapeutic intervention. Employing the EGFR-mutant H1975 parental (Par) cell line and its Osi-resistant (OsiR) counterpart, we integrated transcriptomics, metabolomics, nuclear and mitochondrial genomics, functional assays and bioanalytical techniques, as well as advanced 3D imaging to comprehensively define the resistant phenotype. We found that OsiR cells exhibit mitochondrial dysfunction, including impaired oxidative phosphorylation (OXPHOS), mitochondrial DNA mutations, and altered mitochondrial gene expression. To describe this systems-level characterization, we introduce the concept of mitochondromics, a comprehensive profiling of mitochondrial genomic, transcriptomic, structural, and functional changes contributing to therapeutic resistance. Metabolomic profiling revealed a significant accumulation of glycolytic intermediates (lactate, pyruvate, acetate, and acetaldehyde) in the extracellular medium, indicating a shift toward glycolysis and activation of alternative metabolic pathways, including the Warburg effect. Notably, we identified the pyruvate-acetaldehyde-acetate (PAA) pathway as a functionally repurposed metabolic route that facilitates NADPH production, which is critical for antioxidant defense and anabolic processes in OsiR cells. Additionally, although the pentose phosphate pathway (PPP) is not the primary source of NADPH in OsiR cells, it plays a supporting role in biosynthesis, contributing to the production of amino acids, nucleotides, and vitamins. Altered expression of enzymes involved in glycolysis, the TCA cycle, and both oxidative and non-oxidative arms of the PPP further supports an adaptive metabolic network promoting cell growth and resistance to Osi. This study reveals a complex metabolic reprogramming in Osi-resistant EGFR-mutant NSCLC, where a newly identified role for the PAA pathway, alongside integrated mitochondromic alterations emerges as key driver of resistance. These insights uncover potential metabolic vulnerabilities of Osi-resistant tumors and provide a foundation for developing therapeutic strategies to counteract resistance and improve osimertinib efficacy. Targeting these metabolic pathways may offer promising avenues for overcoming resistance in clinical settings.

cancer biology↗

bioRxiv2021

Ciliated protozoa from industrial WWTP activated sludge: a biodiversity survey including trophic interactions and redescription of Bakuella subtropica (Spirotrichea, Hypotrichia) according to Next Generation Taxonomy

Optimization of wastewater treatment with biological processes is a fundamental challenge of modern society. During past years new technologies have been developed for the purpose and prokaryotic organisms involved in the process extensively investigated. Nevertheless, relatively few studies so far analysed the protozoan community in these systems using modern integrative approaches, despite its obvious role in shaping ecological dynamics and, possibly, process efficiency. In the present study, we characterized the ciliate community in biological reactors of an Italian industrial (tannery) wastewater treatment plant (WWTP) applying modified Ludzack-Ettinger (MLE) process. This plant is characterized by moderate salinity, high solids retention time and high concentration of organic compounds, including a significant recalcitrant fraction. We performed the morphological and 18S rDNA characterizations of almost all the 21 ciliates retrieved along a one-year sampling period, and provided preliminary data on species occurrence, community dynamics, and trophic interactions. Only 16 species were observed on the sample collection day and most of them had an occurrence higher than 50%. The most frequently occurring and highly abundant organisms were Aspidisca cf. cicada, Euplotes spp., Paramecium calkinsi, and Phialina sp. Cyclidium cf. marinum was only found on a single date and its presence was possibly related to a summer break-induced perturbation. All the species showed the capability to survive the short oxic/anoxic cycling typical of the studied WWTP process. Intriguingly, some of them (i.e., Bakuella subtropica and Trochiliopsis australis) turned out to be species isolated from brackish natural environment rich in organic load as well. As for B. subtropica, we provided an emended redescription according to the most recent taxonomy standards that include also mitogenomic sequencing.

zoology↗

bioRxiv2019

Outwitting planarians antibacterial defence mechanisms: Rickettsiales bacterial trans-infection from Paramecium multimicronucleatum to planarians

Most of the microorganisms belonging to genera responsible for vector-borne diseases (VBD) have hematophagous arthropods as vector/reservoir. Recently, many new species of microorganisms phylogenetically related to agents of VBD were found in a variety of aquatic eukaryotic hosts, in particular, numerous new bacterial species related to the genus Rickettsia (Alphaproteobacteria, Rickettsiales) were discovered in protist ciliates and other unicellular eukaryotes. Although their pathogenicity for humans and terrestrial animals is not known, these bacteria might act as etiological agents of possible VBD of aquatic organisms, with protist as vectors. In the present study, we characterized a novel strain of the Rickettsia-Like Organism (RLO) endosymbiont \"Candidatus (Ca.) Trichorickettsia mobilis\" in the macronucleus of the ciliate Paramecium multimicronucleatum through Fluorescence In Situ Hybridization (FISH) and molecular analyses. Ultrastructural investigations on the presence of flagella confirmed previous studies on the same bacterial species. The potential trans-infection per os of this bacterium to planarians (Dugesia japonica), a widely used model system able to eliminate a wide range of bacteria pathogenic to humans and other Metazoa, was further verified. Ciliate mass cultures were set up, and trans-infection experiments were performed by adding homogenized paramecia to food of antibiotic-treated planarians, performed. Treated and non-treated (i.e. control) planarians were investigated at day 1, 3, and 7 after feeding for endosymbiont presence by means of PCR and ultrastructural analyses. Obtained results were fully concordant and suggest that this RLO endosymbiont can be transferred from ciliates to metazoans, being detected up to day 7 in treated planarian enterocytes inside and, possibly, outside phagosomes.

microbiology↗

bioRxiv2019

Next generation taxonomy: integrating traditional species description with the holobiont concept and genomic approaches - The in-depth characterization of a novel Euplotes species as a case study

In 1991 Margulis defined holobionts as the assemblage of \"two or more organisms, members of different species\" which remain associate \"throughout a significant portion of the life history\". In recent times, holobionts have been described among many and far-related groups of living beings, such as plants, algae, insects, corals, and even humans. These studies have arisen an increasing interest in different contexts but, to our knowledge, the holobiont concept has not been applied in taxonomy. Here we propose a new approach to modern taxonomy, aimed to integrate the holobiont concept and genomic and bioinformatic analyses with the classical/morphological tools traditionally used in taxonomy. The inclusion of symbiont morphology, and of mitochondrial and symbiont genomes will allow the discipline to move toward what could become the \"next generation taxonomy\". As an example of this new paradigm in the characterization of holobionts, we herein provide the taxonomic description of the ciliate protist Euplotes vanleeuwenhoeki sp. nov. (Euplotia, Ciliophora) and its bacterial endosymbiont \"Candidatus Pinguicoccus supinus\" gen. nov., sp. nov. (Opitutae, Verrucomicrobia). Interestingly, we found that this endosymbiont has an extremely reduced genome (~163 Kbp), which is suggestive of a high integration with the host and represents the first case of such an extreme reduction in Verrucomicrobia, and the first case in a protist host.

zoology↗

bioRxiv2018

The extracellular association of the bacterium \"Candidatus Deianiraea vastatrix\" with the ciliate Paramecium suggests an alternative scenario for the evolution of Rickettsiales

Rickettsiales are a lineage of obligatorily intracellular Alphaproteobacteria, encompassing important human pathogens, manipulators of host reproduction, and mutualists. Here we report the discovery of a novel Rickettsiales bacterium associated with Paramecium, displaying a unique extracellular lifestyle, including the ability to replicate outside host cells. Genomic analyses show that the bacterium possesses a higher capability to synthesize amino acids, compared to all investigated Rickettsiales. Considering these observations, phylogenetic and phylogenomic reconstructions, and re-evaluating the different means of interaction of Rickettsiales bacteria with eukaryotic cells, we propose an alternative scenario for the evolution of intracellularity in Rickettsiales. According to our reconstruction, the Rickettsiales ancestor would have been an extracellular and metabolically versatile bacterium, while obligate intracellularity and genome reduction would have evolved later in parallel and independently in different sub-lineages. The proposed new scenario could impact on the open debate on the lifestyle of the last common ancestor of mitochondria within Alphaproteobacteria.

evolutionary biology↗