Toxopsis calypsus gen. nov., sp. nov. (Cyanobacteria, Nostocales) from cave ‘Francthi’, Peloponnese, Greece: a morphological and molecular evaluation

Abstract

Representatives of a new cyanobacterial genus, Toxopsis Lamprinou & Pantazidou gen. nov., were found in fresh material from Cave ‘Francthi’ (Peloponnese, Greece) and isolated in cultures. Ecological data relating to the environmental parameters of the sampling sites are provided, such as the photosynthetically active radiation (PAR), temperature and relative humidity. Morphological characteristics and the life cycle of the type species Toxopsis calypsus Lamprinou & Pantazidou sp. nov. were studied using light microscopy and scanning and transmission microscopy. Molecular analysis based on the 16S rRNA gene sequence was also conducted. Toxopsis calypsus sp. nov. is a false-branched nostocalean cyanobacterium with both isopolar and heteropolar filaments bearing mono-pored and bi-pored heterocysts, and also hormogonia and akinetes. Isopolar filaments adhere by the centre to the substrate and are found mainly in fresh material and in young cultures; heteropolar filaments bearing a basic mono-pore heterocyst are dominant in aged (more than one-year-old) cultures. According to the revised taxonomic classification system of Komárek & Anagnostidis (1989) [Komárek, J. & Anagnostidis, K. (1989). Algol Stud, 56, 247–345] based mainly on morphological data, the new genus described here shares morphological characters with both nostocalean families Scytonemataceae and Microchaetaceae, showing similarities in particular to Scytonematopsis contorta [Vaccarino, M. A. & Johansen, J. R. (2011). Fottea 11, 149–161], Microchaetaceae. Molecular data from the 16S rRNA sequence determined in this paper showed that Toxopsis calypsus sp. nov. is more related to the family Microchaetaceae, and the five phylotypes analysed by PCR showed that the closest nostocalean relatives are Tolypothrix distorta SAG 93.79 (GenBank accession no. GQ287651) and Coleodesmium sp. ANT.L52B.5 (AY493596) with 95–96 % and 96 % similarity, respectively. In contrast, the five phylotypes showed a distant similarity to Scytonematopsis contorta (<91 %). The phenotypic and genetic traits strongly supported the classification of the five phylotypes as a new taxon for which the name Toxopsis calypsus Lamprinou & Pantazidou gen. nov., sp. nov. is proposed.

Distribution survey of Cyanobacteria in three Greek caves of Peloponnese

“…Iphinoe spelaeobios Lamprinou & Pantazidou (Lamprinou et al, 2011), Iphinoe cf. spelaeobios Lamprinou & Pantazidou (Lamprinou et al, 2012b), Toxopsis calypsus Lamprinou & Pantazidou (Lamprinou et al, 2012a), Phormidium melanochroun Lamprinou & Pantazidou (Lamprinou et al, 2012c), enhancing the view that hypogean environments in general may favor speciation or physiological adaptation (Lamprinou et al, 2009;Zammitt et al, 2011). Therefore, the species distribution in relation to cave morphology, lithic substrate, and microclimatic conditions still remain a challenge for further research.…”

“…Hoffmann, 2002) into three groups: a) 'troglobitic' species, obligatory cavernicoles that cannot survive outside the cave, b)'troglophilic' species, growing and reproducing in caves, and c) 'trogloxenic' species, accidentally reaching the cave environment. Concerning cyanobacteria, some species such as Loriella osteophila Borzi, Scytonema julianum (Kützing) Meneghini Richter can be considered as troglophiles (Hoffmann, 2002 et al, 1991), Israel (Friedmann, 1964;Vinogradova et al, 1998), Hungary (Claus, 1964Hajdu, 1966), France (Bourelly & Dupuy, 1973;Leclerc et al, 1983), Germany (Dobat, 1977), Italy (Borzi, 1917;Skuja, 1970;Abdelahad, 1989), Romania (Şerbānescu & Decu, 1962), Slovenia (Mulek & Kosi, 2008), Spain (Ariño et al, 1997;Ascencio & Aboal, 1996, 2000aMartinez & Asencio, 2010;Hernández-Mariné et al, 2001;Roldán et al, 2004), and Greece (Anagnostidis et al, 1982;Lamprinou et al, 2009Lamprinou et al, , 2011Lamprinou et al, , 2012a. Despite all the aforementioned mainly floristic studies, it is only recently that cave microbiology has been established as a new field combining aspects of microbial life, geology and chemistry that influence the natural cave processes (Mulek & Kosi, 2008).…”

Hassallia littoralis sp. nov. (Cyanobacteria, Microchaetaceae) from Mexico’s marine supralittoral based on morphological and molecular evidence

“…ANT and H. andreassenii have been isolated from Antarctica, therefore further studies are needed to compare these two strains. Komárek et al (2012), Lamprinou et al (2012) and Hauer et al (2013), the scarce number of sequences available in this group probably influences these values. According to Berrendero et al (2011) and Hauer et al (2013), the Microchaetaceae family needs a more detailed analysis of its members.…”

“…In the last decade the family Microchaetaceae has had important changes; the recent addition of new genericlevel taxa indicates a great activity derived from the study of new or not well known habitats, such as tropical or extreme ones (Flechtner et al 2002, Cassamata et al 2006, Sant'Anna et al 2010, Novis & Visnovsky 2011, Lamprinou et al 2012). These taxa were described mainly using a polyphasic approach including molecular methods, but when this was not possible new taxa description has been based on a detailed morphological and ecological characterization of populations (Sant'Anna et al 2010).…”

“…The family Microchaetaceae (Nostocales) has been under intensive revision, with several new species and even genera being described, such as Spirirestris Flechtner & Johansen in Flechtner et al (2002: 6), Rexia Casamatta, Gomez & Johansen (2006: 23), Streptostemon Sant'Anna, Azevedo, Kastovský & Komárek (2010: 220), Ophiotrhix Sant'Anna, Azevedo, Kastovský & Komárek (2010: 218), Godleya Novis & Visnovsky (2011: 14), Toxopsis Lamprinou & Pantazidou in Lamprinou et al (2012Lamprinou et al ( : 2872, and Calochaete Hauer, Bohunická & Mühlsteinová (2013: 38). Currently, the family Microchaetaceae contains 13 genera (Table 1).…”