Valentina Serra

University of Pisa

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Co-Authors

Giulio Petroni

University of Pisa

Letizia Modeo

University of Pisa

Leandro Gammuto

University of Pavia

Sergei I. Fokin

North-West Institute of Management

Michele Castelli

University of Pavia

B. V. Sandeep

Andhra University

Venkatamahesh Nitla

University of Pisa

Franco Verni

University of Pisa

Charan Kumar Basuri

Ministry of Earth Sciences

Michela Balestri

Oxford Brookes University

Cooperative Institutions

Centre National de la Recherche Scientifique

Natural History Museum

American Museum of Natural History

Chinese Academy of Sciences

Real Jardín Botánico

Consejo Superior de Investigaciones Científicas

University of Pisa

Weatherford College

École Pratique des Hautes Études

Czech Academy of Sciences, Institute of Botany

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Bacterial symbiosis in ciliates (Alveolata, Ciliophora): Roads traveled and those still to be taken

Journal of Eukaryotic Microbiology (2022)

Sergei I. Fokin Valentina Serra

The diversity of prokaryotic symbionts in Ciliophora and other protists is fascinatingly rich; they may even include some potentially pathogenic bacteria. In this review, we summarize currently available data on biodiversity and some morphological and biological peculiarities of prokaryotic symbionts mainly within the genera Paramecium and Euplotes. Another direction of ciliate symbiology, neglected for a long time and now re-discovered, is the study of epibionts of ciliates. This promises a variety of interesting outcomes. Last, but not least, we stress the new technologies, such as next generation sequencing and the use of genomics data, which all can clarify many new aspects of relevance. For this reason, a brief overview of achievements in genomic studies on ciliate's symbionts is provided. Summing up the results of numerous scientific contributions, we systematically update current knowledge and outline the prospects as to how symbiology of Ciliophora may develop in the near future.

10.1111/jeu.12886

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Citations (26)

Morphology, ultrastructure, genomics, and phylogeny of Euplotes vanleeuwenhoeki sp. nov. and its ultra-reduced endosymbiont “Candidatus Pinguicoccus supinus” sp. nov.

Scientific Reports (2020)

Valentina Serra Leandro Gammuto Venkatamahesh Nitla Michele Castelli Olivia Lanzoni

Taxonomy is the science of defining and naming groups of biological organisms based on shared characteristics and, more recently, on evolutionary relationships. With the birth of novel genomics/bioinformatics techniques and the increasing interest in microbiome studies, a further advance of taxonomic discipline appears not only possible but highly desirable. The present work proposes a new approach to modern taxonomy, consisting in the inclusion of novel descriptors in the organism characterization: (1) the presence of associated microorganisms (e.g.: symbionts, microbiome), (2) the mitochondrial genome of the host, (3) the symbiont genome. This approach aims to provide a deeper comprehension of the evolutionary/ecological dimensions of organisms since their very first description. Particularly interesting, are those complexes formed by the host plus associated microorganisms, that in the present study we refer to as "holobionts". We illustrate this approach through the description of the ciliate Euplotes vanleeuwenhoeki sp. nov. and its bacterial endosymbiont "Candidatus Pinguicoccus supinus" gen. nov., sp. nov. The endosymbiont possesses an extremely reduced genome (~ 163 kbp); intriguingly, this suggests a high integration between host and symbiont.

Morphology

Candidatus

10.1038/s41598-020-76348-z

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Citations (48)

Ciliate communities and hidden biodiversity in freshwater biotopes of the Pistoia province (Tuscany, Italy)

European Journal of Protistology (2015)

Alessia Rossi Vittorio Boscaro Daniela Carducci Valentina Serra Letizia Modeo

Biotope

10.1016/j.ejop.2015.12.005

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Citations (28)

Host association and intracellularity evolved multiple times independently in the Rickettsiales

Nature Communications (2024)

Michele Castelli Tiago Nardi Leandro Gammuto Greta Bellinzona Elena Sabaneyeva

The order Rickettsiales (Alphaproteobacteria) encompasses multiple diverse lineages of host-associated bacteria, including pathogens, reproductive manipulators, and mutualists. Here, in order to understand how intracellularity and host association originated in this order, and whether they are ancestral or convergently evolved characteristics, we built a large and phylogenetically-balanced dataset that includes de novo sequenced genomes and a selection of published genomic and metagenomic assemblies. We perform detailed functional reconstructions that clearly indicates "late" and parallel evolution of obligate host-association in different Rickettsiales lineages. According to the depicted scenario, multiple independent horizontal acquisitions of transporters led to the progressive loss of biosynthesis of nucleotides, amino acids and other metabolites, producing distinct conditions of host-dependence. Each clade experienced a different pattern of evolution of the ancestral arsenal of interaction apparatuses, including development of specialised effectors involved in the lineage-specific mechanisms of host cell adhesion and/or invasion.

Obligate

Alphaproteobacteria

Lineage (genetic)

Horizontal Gene Transfer

10.1038/s41467-024-45351-7

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Citations (5)

Life in a fragment: Evolution of foraging strategies of translocated collared brown lemurs, Eulemur collaris, over an 18‐year period

American Journal of Primatology (2020)

Giuseppe Donati Marco Campera Michela Balestri Marta Barresi Kristina Kesch

Abstract While the drivers of primate persistence in forest fragments have been often considered at the population level, the strategies to persist in these habitats have been little investigated at the individual or group level. Considering the rapid variation of fragment characteristics over time, longitudinal data on primates living in fragmented habitats are necessary to understand the key elements for their persistence. Since translocated animals have to cope with unfamiliar areas and face unknown fluctuations in food abundance, they offer the opportunity to study the factors contributing to successful migration between fragments. Here, we illustrated the evolution of the foraging strategies of translocated collared brown lemurs ( Eulemur collaris ) over an 18‐year period in the Mandena Conservation Zone, south‐east Madagascar. Our aim was to explore the ability of these frugivorous lemurs to adjust to recently colonized fragmented forests. Although the lemurs remained mainly frugivorous throughout the study period, over the years we identified a reduction in the consumption of leaves and exotic/pioneer plant species. These adjustments were expected in frugivorous primates living in a degraded area, but we hypothesize that they may also reflect the initial need to cope with an unfamiliar environment after the translocation. Since fragmentation is often associated with the loss of large trees and native vegetation, we suggest that the availability of exotic and/or pioneer plant species can provide an easy‐to‐access, nonseasonal food resource and be a key factor for persistence during the initial stage of the recolonization.

Frugivore

Habitat Fragmentation

Insectivore

10.1002/ajp.23106

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Citations (11)

Critical revision of the family Plagiopylidae (Ciliophora: Plagiopylea), including the description of two novel species, Plagiopyla ramani and Plagiopyla narasimhamurtii, and redescription of Plagiopyla nasuta Stein, 1860 from India

Zoological Journal of the Linnean Society (2018)

Venkatamahesh Nitla Valentina Serra Sergei I. Fokin Letizia Modeo Franco Verni

10.1093/zoolinnean/zly041

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Citations (39)

Holospora-like bacteria “Candidatus Gortzia yakutica” and Preeria caryophila: Ultrastructure, promiscuity, and biogeography of the symbionts

European Journal of Protistology (2023)

Sergei I. Fokin N. Lebedeva А. А. Потехин Leandro Gammuto Giulio Petroni

Two already known representatives of Holospora-like bacteria, "Candidatus Gortzia yakutica" from Paramecium putrinum and Preeria caryophila, originally retrieved from the Paramecium aurelia complex, were found in new hosts: Paramecium nephridiatum and Paramecium polycaryum, respectively. In the present study, these bacteria were investigated using morphological and molecular methods. For "Ca. G. yakutica", the first details of the electron microscopic structure in the main and new hosts were provided. Regarding Pr. caryophila, the ultrastructural description of this species was implemented by several features previously unknown, such as the so called "membrane cluster" dividing periplasm from cytoplasm and fine composition of infectious forms before and during its releasing from the infected macronucleus. The new combinations of these Holospora-like bacteria with ciliate hosts were discussed from biogeographical and ecological points of view. Host specificity of symbionts as a general paradigm was critically reviewed as well.

Macronucleus

Paramecium aurelia

Candidatus

Prokaryote

10.1016/j.ejop.2023.125998

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Citations (1)

Parablepharisma (Ciliophora) is not a Heterotrich: A Phylogenetic and Morphological Study with the Proposal of New Taxa

Protist (2020)

Pedro H. Campello‐Nunes Noemi M. Fernandes Franziska Szokoli Sergei I. Fokin Valentina Serra

Sister group

Phylogenetic relationship

10.1016/j.protis.2020.125716

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Citations (14)

“Candidatus Hafkinia simulans” gen. nov., sp. nov., a Novel Holospora-Like Bacterium from the Macronucleus of the Rare Brackish Water Ciliate Frontonia salmastra (Oligohymenophorea, Ciliophora): Multidisciplinary Characterization of the New Endosymbiont and Its Host

Microbial Ecology (2019)

Sergei I. Fokin Valentina Serra Filippo Ferrantini Letizia Modeo Giulio Petroni

Candidatus

Sister group

Monophyly

10.1007/s00248-018-1311-0

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Citations (39)

Characterization of a Pseudokeronopsis Strain (Ciliophora, Urostylida) and Its Bacterial Endosymbiont “Candidatus Trichorickettsia” (Alphaproteobacteria, Rickettsiales)

Diversity (2022)

Michele Castelli Valentina Serra Leandro Gammuto Marcus Vinicius Xavier Senra Letizia Modeo

Symbiotic associations between bacteria and ciliate protists are rather common. In particular, several cases were reported involving bacteria of the alphaproteobacterial lineage Rickettsiales, but the diversity, features, and interactions in these associations are still poorly understood. In this work, we characterized a novel ciliate protist strain originating from Brazil and its associated Rickettsiales endosymbiont by means of live and ultrastructural observations, as well as molecular phylogeny. Though with few morphological peculiarities, the ciliate was found to be phylogenetically affiliated with Pseudokeronopsis erythrina, a euryhaline species, which is consistent with its origin from a lagoon with significant spatial and seasonal salinity variations. The bacterial symbiont was assigned to “Candidatus Trichorickettsia mobilis subsp. hyperinfectiva”, being the first documented case of a Rickettsiales associated with urostylid ciliates. It resided in the host cytoplasm and bore flagella, similarly to many, but not all, conspecifics in other host species. These findings highlight the ability of “Candidatus Trichorickettsia” to infect multiple distinct host species and underline the importance of further studies on this system, in particular on flagella and their regulation, from a functional and also an evolutionary perspective, considering the phylogenetic proximity with the well-studied and non-flagellated Rickettsia.

Alphaproteobacteria

Candidatus

Prokaryote

Protist

Lineage (genetic)

10.3390/d14121032

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Citations (1)