Description of two new species of Euplotes and Euplotes rariseta from Antarctica

Valbonesi, Alessandro; Luporini, Pierangelo

doi:10.1007/bf00236521

Cited by 52 publications

(49 citation statements)

References 12 publications

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“…(1989) and four populations of E. rariseta (Curds et at, 1974;Wilbert & Kahan, 1981;Dallai et al, 1981;Valbonesi & Luporini, 1990), which are the species most closely related to E. margherensis.…”

Section: Discussionmentioning

confidence: 97%

Description ofEuplotes margherensisnov. spec. (Ciliophora, Hypotrichida) from the Lagoon of Venice

Coppellotti

Cisotto

1996

Italian Journal of Zoology

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Section: Discussionmentioning

confidence: 97%

Description ofEuplotes margherensisnov. spec. (Ciliophora, Hypotrichida) from the Lagoon of Venice

Coppellotti

Cisotto

1996

Italian Journal of Zoology

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“…These strains were initially analyzed morphologically to assign their species status, by measuring and counting common diagnostic parameters such as cell body dimensions, number and positional patterns of ciliary organelles, and number and geometry of cortical alveoli. Only a minority of strains have been found to represent known Euplotes species, such as E. rariseta and E. kahli (Valbonesi and Luporini 1990a;unpublished data), whereas the large majority appeared to represent new Euplotes species of which, however, only few have received official taxonomic designations so far (Valbonesi and Luporini 1990a, b).…”

Section: Collection Sites and Polar Euplotes Speciesmentioning

confidence: 95%

“…Analyses of mating interactions, initially restricted to the Antarctic strains which were the first to be collected and morphologically diagnosed as representative of E. nobilii (Valbonesi and Luporini 1990a), provided evidence that, like other Euplotes species (Dini and Nyberg 1993), E. nobilii is represented in nature by multiple mating types that mediate their activity through diffusible, cell type-specific signaling pheromones (Felici et al 1999). With the extension of the study of mating interactions to Fuegian and Arctic strains it was first shown that some pheromones structurally characterized from Antarctic and Arctic strains were represented by helical proteins in all members of the same homologous family (Alimenti et al 2009;Di Giuseppe et al 2011).…”

Section: Mating and Breeding Interactionsmentioning

confidence: 99%

Pole-to-Pole Gene Flow in Protozoan Ciliates

et al. 2012

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Microorganisms represent the smallest but arguably most important component of the ocean life. They are essential to all nutrient cycles because they form the bottom of the marine food chain and outnumber all other marine species by orders of magnitude. Sampling of remote and inaccessible habitats and large-scale genomic analysis have shown how little we know about the microbial life in the oceans, and how our poor knowledge of the marine chemistry and biology is preventing us from foreseeing the detrimental effects that a too rapidly changing world has on the oceans’ ecosystems. In this context, polar microorganisms are attracting particular interest because of their role in global-scale biogeochemical cycles, in particular the carbon dioxide exchange with the atmosphere (Falkowski et al. 2008). Considering this interest, planktonic and benthic microbial communities from Arctic and Antarctic areas have become the focus of more systematic samplingand rigorous analyses for their taxonomic, prokaryotic (bacterial) and eukaryotic (protist), biodiversity. A relevant result of these analyses was the finding of microbial species that, like a diverse range of plant and animal species (Lindberg 1991; Crame 1993), warrant the definition ‘‘bipolar’’ (or ‘‘anti-tropical’’), i.e. species represented by high-latitude populations physically separated in distribution across the tropics (Darling et al. 2000; Montresor et al. 2003; Brandt et al. 2007; Pawlowski et al. 2007). This concept of species bipolarity has inherently raised the intriguing question whether co-specific Antarctic and Arctic populations evolved independently since the effective separation (approximately 10–15 million years ago) between the Arctic and Antarctic cold-water provinces, or whether a trans-tropical gene flow ensures that these polar populations maintain genetic continuity (Darling et al. 2000). Morphological studies alone are clearly insufficient to address this question, due to recurrent phenomena of parallel or convergent morphological evolution that take place under similar environmental forces. Therefore, more solid grounds supporting the concept of species bipolarity have been obtained in some species of foraminifera and dinozoans from analysis of genetic variation in sequences of the small subunit (SSU) rRNA nuclear gene (Darling et al. 2000; Montresor et al. 2003; Brandt et al. 2007; Pawlowski et al. 2007). Nevertheless, unless the calibration of a molecular clock is supported by abundance in fossil records, as is the case in foraminifera (Pawlowski et al. 1997), also this genetic approach is impaired by the fact that the same DNA regions may evolve at different rates among closely related organisms. A solution to overcoming this challenge is provided by the well-defined, monophyletic group of ciliates which are ideal organisms for the analysis of the breeding structure of natural microbial populations and, therefore, for obtaining data which satisfy the interbreeding criterion on which the biological (Darwinian) concept of species is founded...

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“…DA dorsal alveoli, DK dorsal kinety, AM adoral membranelles, FVC fronto-ventral cirri, TC transverse cirri, CC caudal cirri, LK lateral kinety. After Valbonesi & Luporini (1990a), modified…”

Section: Genetic Relationshipsmentioning

confidence: 98%

“…Here we update and describe new data on the genetic relationships of high-latitude populations of three Euplotes species, namely E. euryhalinus, E. nobilii, and E. petzi, which are well distinct on morphological, eco-physiological, and phylogenetic grounds (Valbonesi & Luporini, 1990a;Achilles-Day et al, 2008;Chen et al, 2013;Di Giuseppe et al, 2014). These relationships were deduced from comparisons of small-subunit ribosomal RNA (SSUrRNA) gene sequences and analyses of mating interactions.…”

Section: Introductionmentioning

confidence: 96%

Genetic relationships in bipolar species of the protist ciliate, Euplotes

et al. 2015

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Protists thrive in polar oceans, where they\ud represent a major driving force for globally important\ud biogeochemical cycles and a key food-web component.\ud Their biogeography is frequently associated to\ud bipolar patterns of distribution. Although conceptually\ud well supported by apparently unrestricted migration\ud rates, the experimental certification of these patterns\ud copes with the protist paucity of morphological\ud characters with taxonomic value and difficulties in\ud applying conventional species concepts. We studied\ud three marine species of the ciliate Euplotes, E.\ud euryhalinus, E. nobilii, and E. petzi, for their bipolar\ud distribution by comparing the SSU-rRNA gene sequences\ud and mating interactions of Antarctic,\ud Patagonian, and Arctic strains. Each species was\ud analogously found not to carry significantly varied\ud SSU-rRNA gene sequences, implying a common\ud occurrence of trans-equatorial genetic mixing. However,\ud mating analyses revealed significant interspecies\ud differences. Scarce Antarctic 9 Arctic strain\ud mating compatibility distinguished E. petzi from E.\ud euryhalinus and E. nobilii, in which mating pairs\ud between Antarctic and Arctic strains were successfully\ud induced. Yet, E. nobilii was the only one of the two\ud species to show cross-fertilizing and fertile mating\ud pairs. Taking the biological concept of species as\ud discriminatory, it was thus concluded that only E.\ud nobilii warrants the definition of genuine bipolar\ud species

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Description of two new species of Euplotes and Euplotes rariseta from Antarctica

Cited by 52 publications

References 12 publications

Description ofEuplotes margherensisnov. spec. (Ciliophora, Hypotrichida) from the Lagoon of Venice

Description ofEuplotes margherensisnov. spec. (Ciliophora, Hypotrichida) from the Lagoon of Venice

Pole-to-Pole Gene Flow in Protozoan Ciliates

Genetic relationships in bipolar species of the protist ciliate, Euplotes

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