Polyploidy and aneuploidy phenomenon by conjugates - a study focused on genus Spirogyra

Knowledge of nuclear cytology in algae remains to be much improved, compared to that in higher plants and animals. Especially, The Euglenophyceae, the Cryptophyceae, the Dinophyceae and the Zygnematophyceae contain many species with ectremely high chromosome numbers of over one hundred (Sarma 1982). Since Strasburger’s (1875) first report for the process of cell division in Spirogyra orthospira, studies on the nuclear cytology (Godward 1954, 1961; Godward and Newnham 1965) and the cytototaxonomy of Spirogyra were carried out (Tatuno and Iiyama 1971, Vedajanani and Sarma, 1978, Abhayavardhani and Sarma, 1983). However, chromosome numbers of this genus were determined for only forty-four identified species (Chaudhary and Agrawal 1996, Kim et al. 2009). Chromosome numbers in Spirogyra ranged from n = 2 in three Japanese species (Tatuno and Iiyama, 1971) to n = 94 in S. nitida (Abhayavardhani and Sarma, 1983). Polyploidization (endomitosis) is a major evolutionary process in plants where hybridization and chromosome doubling induce enormous genomic stress and can generate genetic and epigenetic modifications (Stebbins, 1971), in which it promotes rapid speciation (Levin, 1983). In contrast, ploidal changes in algae have been studied, i.e. Nichols (1980) reported that polyploidization is known in most major algal taxa, especially in the green algae (chlorophyta). In this study was used culture collections from various habitats. These cultures provided ecological preferences of single taxa and ploidal variants. Cell morphology was obtained from both field material and cultures. In this context, the traditional characters was compared with cellular DNA-contents and chromosome numbers. We supposed that additional species complexes will be delimited and that polyploidy is widespread among Spirogyra. Special attention was paid to the different karyological methods

Differences in the ultrastructure of two selected taxa of phytoplankton in a thermally stratified Lake Holzmaar (Germany)

This paper presents the results of ultrastructural studies and ecological aspects of some phytoplankton species belongingto the groups of cyanobacteria (Planktothrix rubescens, Synechocystis aquatilis) and green algae (Desmodesmus grahneisii). Specimens were collected during summertime from the mesotrophic and stratified Lake Holzmaar (Western Germany) as planktonic from the pelagic zone. The highest cyanobacterium P. rubescens concentration was detected in the metalimnion where the alkaline pH, low phosphorus and high nitrogen contents were recorded. It was characterized by straight filaments up to 1000 um long and 5.4-8 um wide and numerous aerotopes in cells. The accompanying algae were identified by ultrastructuralanalysis and photographic documentation was provided. In the case of D. grahneisii, chloroplast was concentrated in the parietal part of cell with one large, oval pyrenoid and, in addition, the granular and spiny cell wall clearly showed important taxonomical criteria for Desmodesmus genera. This is in contrast with cyanobacterium S. aquatilis where the presence of a homogeneous content with visible chromatoplasma was mostly distributed through the cell. This algal association was stable in the epilimnion characterized by the presence of high temperature, pH values, nitrate nitrogen and oxygen concentrations

Morphological and ultrastructural studies on Ulva flexuosa subsp. pilifera (Chlorophyta) from Poland

Ulva flexuosa subsp. pilifera (Kütz.) M. J. Wynne 2005 (= Enteromorpha pilifera Kützing 1845) was previously found in Argentina, the Czech Republic, Germany, Hungary, Romania, Slovakia and Sweden, recently also in Poland. The genus Ulva was first time described as Enteromorpha. Interestingly, Enteromorpha is used nowadays as a synonym for Ulva, a development which is based on molecular data. The morphologies of both young and mature specimens were studied, and most life cycle stages could be observed. Further, the formation of calcium carbonate crystals on the surface of Ulva thalli seems to influence the arrangement of the cells. A detailed ultrastructural (TEM) analysis of cell walls is presented. The TEM reveals in great details highly complex, irregular structures with stratification lines.The project was supported by funding from the Polish Ministry of Science, grant No. NN 304 013 437 and partially funded by the project GDWB-07/ 2011.822157163Acta Societatis Botanicorum Polonia

Ulva flexuosa subsp. pilifera (Chlorophyta, Ulvophyceae) from the Wielkopolska region (West Poland): a new observation of the ultrastructure of vegetative cells

Ulva flexuosa subsp. pilifera previously known from northern Poland, from the channel near Szczecin and ponds near Łódź, has recently been found in the Malta Reservoir in the Wielkopolska (West Poland) region. Specimens collected in the Wielkopolska region were examined in detail, also under a transmission electron microscope (TEM). The morphometric analysis of Ulva thalli (both young and mature specimens) was performed in order to study the differences in the ultrastructure of vegetative cells. Rectangular cells in young thalli measured from 32.21 - 55.81 μm to 20.24 – 35.12 μm, and they formed clear longitudinal rows, while cells in the mature specimens ranged from 25.09 – 47.66 μm to 18.90 – 31.56 μm. This study indicates that vegetative cells of the mature thalli show tendency towards distortions of both the longitudinal and transverse cells arrangement. This distortion is determined by the development of possible carbonate calcium crystals on the thalli surface. The ultrastructural analysis (TEM) confirmed that the structure and placement of thylakoids is genus/species specific.This work was supported by the grant NN 304 013 437.422209215Oceanological and Hydrobilogical Studie

Phenomenon Spirogyra - microevolution agents polyploidy and aneuploidy by conjugates

Isolation, cultivation and identification of Spirogyra morphotypes are fundamentals for a continued study on its infra- and interspecific relationships. The monographs published by Czurda (1932), Kolkwitz and Krieger (1941), Transeau (1951), Randhawa (1959) or Kadlubowska (1984) are based solely on morphological diacritical features of field collected material. However, Allen (1958) was the first to observe polyploidy in clonal cultures and therefore introduced the term “species complex” for derived groups with euploidal diffences and distinct morphology leading to multiple “traditional” species. A “species complex” in Spirogyra consists of a series of morphotypes of different ploidy emanating from a clonal morphotype. Hoshaw et al. (1985, 1987) confirmed polyploidy in Spirogyra and McCourt and Hoshaw (1990) focused on problems associated with species concepts in this genus. Richard et al. (1990) confirmed that polyploidy plays a major role in morphological diversity of Spirogyra filaments. Recently, cytological study of Kim et al. (2009) underlined the aneuploidy phenomenon in the genus. Summing up, the uncertain position of Spirogyra within the Zygnemataceae and its complex species structure can be resolved only by detailed studies of clonal cultures including traditional characters, karyology (Kim et al. 2009) and molecular markers as provided in this study. Knowledge of nuclear cytology in algae remains to be much improved, compared to that in higher plants and animals. We supposed that additional species complexes will be delimited and that polyploidy is widespread among Spirogyra. Special attention was paid to the different karyological methods

Cyanobacteria of several wells in Brno surroundings

Wet stones near the wells form a specific microhabitat for the occurrence of epilithic, benthic and epiphytic cyanobacteria and algae. In four wells (Prosba lesa, U sovy, Čertík, U památníku letců) 15 little known cyanobacteria species (namely from the group of Chroococcales) were identified. These microhabitats belong to oligosaprobic water sites

Macroinvertebrate herbivores and epilithon algae community of a stream affected by mineralized heated mining water inflow

The main aims of this study were to analyse the effect of a mineralized heated water inflow from a uranium ore processing plant on the abundance and diversity of epilithon and macroinvertebrate herbivores as well as to identify changes in functional feeding groups. In total, four sampling sites were selected. One site was on the mining water tributary and three sites in a recipient natural stream (the Nedvědička River, Czech Republic): one of them upstream and two downstream from the mining effluent. Samples were taken monthly during the period 2008–2009. The number of species in the epilithon was higher downstream from the tributary and we also recorded a small increase in density. We observed significant changes in the taxonomical composition of epilithon and macroinvertebrate communities downstream from the tributary. Taxa richness of macroinvertebrates was similar between sampling sites. A small drop in macroinvertebrate abundance immediately downstream from the tributary was followed by a significantly elevated number of herbivores, especially scraper-collectors, at the more downstream site. Alteration of the species composition and abundance of herbivorous macroinvertebrates in the Nedvědička River could be explained by a combination of a change in food availability and the physico-chemical properties of the water.The mining water altered abundance and taxa richness of herbivorous macroinvertebrates and their food – epilithic algae. Changes in community composition and function were recorded, scraper-collectors and invasive species became dominant in affected sites. Understanding the ecological effects of mining water effluent is useful for river protection management

Diatom species diversity and their ecological patterns on different substrates in two karstic streams in the Slovak Karst

Many karstic streams are threatened both by anthropogenic and climate changes, but little is known about their algal biodiversity and conservation value, especially in the Slovak Karst. Diatom assemblages occurring on seven substrates, including stones, mud, submerged mosses and filamentous algae: Cladophora glomerata, Vaucheria sp., Ulothrix zonata, Spirogyra sp. in two nameless karstic streams in the Krásnohorská Dlhá Lúka Village and the Gombasek Cottage Settlement (the Slavec Village) in the Košice Region of central-eastern Slovakia (the Silická Plateau) were studied. A total of 124 diatom taxa were found at four sites, where epilithic and epiphytic diatom assemblages dominated. Both species' richness and Shannon-Wiener indices showed congruent biotic integrity. The dominant taxa were alkaliphilous, halophobous-oligohalobous, requiring xeno-oligosaprobic and oligotrophic waters. Diatoms include: Diploneis krammeri, Encyonema ventricosum, Gomphonema acuminatum, Gyrosigma attenuatum, Navicula tripunctata, and Paraplaconeis cracoviensis. The latter species is a new report for Slovakia, reflecting the calcareous, geological nature of the Silická Plateau (the Slovak Karst). Diatom assemblages in two karstic streams consisted mainly of small-celled species of Achnanthidium, Amphora, Caloneis, Planothidium, and Stauroneis. Our results showed that the diatom assemblages were mostly structured by environmental factors of calcium and pH gradients, confirmed by canonical variates analysis (CVA) and Monte Carlo permutation tests. However, unique spatial and biological gradients, specific to different guilds related to each other, were also evident. The Slovak karstic streams should be especially protected and regularly monitored

X-ray Fluorescence Techniques in Determining the Habitat Preferences of Species—Ulva pilifera (Ulvales, Chlorophyta) from Montenegro Case Study

The paper presents four new sites where bright green Ulva thalli were found inhabiting freshwater (a river, a ditch, the Milet Canal) and marine (on the rocky shore of the Adriatic Sea) habitats in Montenegro. The aims of this study were to determine, for the first time, whether specimens of Ulva pilifera collected in Montenegro are phylogenetically and morphologically the same species as the one occurring in Europe. Using total reflection X-ray fluorescence (TXRF) and wavelength dispersive X-ray fluorescence (WDXRF) techniques it assessed the elemental composition of their thalli and its influence to colonise new habitats. Elements: Al, As, Ba, Br, Ca, Cl, Cr, Cu, Fe, Hf, I, K, Mg, Mn, Na, Ni, P, Pb, Rb, S, Si, Sr, Ti, V, and Zn were determined. The highest elemental concentrations were found for Ca = 16.3% (using WDXRF) and for Sr = 292 ppm (using TXRF) in the Ulva thalli. Ulva pilifera analysed from Montenegro, based on classical morphological methods and molecular techniques, are closely related to the same species from inland and coastal waters throughout Europe. The analysis of trace elements showed that the metal content in Ulva thalli is correlated with the trace elements in water and sediments. Ulva pilifera fits numerous features that make it one of the bioindicators of marine pollution, thanks to its worldwide distribution and capacity to accumulate trace elements

Analyse phylogénétique des cyanobactéries terrestres résistantes à la mise en culture et avec des larges gaines (Stigonema spp. et Petalonema alatum, Nostocales, Cyanobacterie) en utilisant le séquençage de cellules ou filaments isolés à partir d'échantillons environnementaux

peer reviewedMolecular assessment of a large portion of traditional cyanobacterial taxa has been hindered by the failure to isolate and grow them in culture. In this study, we developed an optimized protocol for single cell/filament isolation and 16S rRNA gene sequencing of terrestrial cyanobacteria with large mucilaginous sheaths, and applied it to determine the phylogenetic position of typical members of the genera Petalonema and Stigonema. A methodology based on a glass-capillary isolation technique and a semi-nested PCR protocol enabled reliable sequencing of the 16S rRNA gene from all samples analyzed. Ten samples covering seven species of Stigonema from Europe, North and Central America, and Hawaii, and the type species of Petalonema from Slovakia were sequenced. Contrary to some previous studies, which proposed a relationship with heteropolar nostocalean cyanobacteria, Petalonema appeared to belong to the family Scytonemataceae. Analysis of Stigonema specimens recovered a unique coherent phylogenetic cluster, substantially broadening our knowledge of the molecular diversity within this genus. Neither the uni- to biseriate species nor the multiseriate species formed monophyletic subclusters within the genus. Typical multiseriate species of Stigonema clustered in a phylogenetic branch derived from uni- to biseriate S. ocellatum Thuret ex Bornet & Flahault in our analysis, suggesting that species with more complex thalli may have evolved from the more simple ones. We propose the technique tested in this study as a promising tool for a future revision of the molecular taxonomy in cyanobacteria.Single cell sequencing of cyanobacteri