shape of chloroplast in zygnema

The investigated genotypes were evenly distributed among genotypes of non-polar origin, and did not form any monophyletic polar clusters. & Delwiche C.F. Two parallel Markov chain Monte Carlo runs were carried out for 3 000 000 generations, each with one cold and three heated chains. They may be cup shaped (Volvox, chlamydomanas), H-shaped (Chlamydomonas biciliata), girdle shaped (Ulothrix), spiral (Spirogyra), reticulate (Oedogonium), stellate (Zygnema) but normally discoid in most of the other groups. 36. Pichrtová M., Kulichová J. From each mat several individual filaments were isolated and cultured (Table 1). 32. & Kim S.J. ). & McCourt R.M. Click here👆to get an answer to your question ️ 1. & Wang J.-C. (1986). Unrelated genotypes may possess a similar chloroplast type and, conversely, genotypes from one lineage (e.g. When algal nutrients are widely available and the environment is suitable, Zygnema frequently fragment as a means of vegetative reproduction. The number of strains isolated for each Zygnema/Zygnemopsis genotype and their geographic origin are given in parentheses. The concern may be greatest during the winter months in temperate regions when algal mats die and decompose, producing a substantial biological oxygen demand caused by respiring bacteria feeding on the decaying organic material. Generally, within the studied Zygnema strains, four groups of plastids were recognized: (i) chloroplasts with very delicate and thin lobules as shown for genotypes N (Fig. Genotype A; Fig. Supplementary material 2. Conjugation and zygospore formation were recorded in a natural sample. 29. In another filamentous conjugating green algal genus, Spirogyra, molecular diversity analysis of sterile strains from Germany and Austria revealed 53 different SSU rDNA genotypes within 130 isolated strains, and the genus was split into eight independent lineages (Chen et al., 2012). Describe this and its shape. Genotypes that do not significantly differ from each other share at least one letter, while those significantly different from each other do not share any letters (p < 0.05; Kruskal–Wallis test with multiple comparisons). Elster J. Drummond et al., 2005; Gontcharov & Melkonian, 2005; Stancheva et al., 2014). Vegetative Body of Zygnema (Fig. Similarly, Stancheva et al. Species Primers RH1 and 1385R (McCourt et al., 2000), and newly designed primers ZygF (5’TATGTCAACCACAAAC3’) and ZygR (5’GTATCAAATTCAAATTTA3’), were used for amplification of the rbcL gene in reactions containing 13.9 µl of sterile Milli-Q water, 2 µl of MgCl2 (25 mM), 2 µl of AmpliTaq Gold 360 Buffer (Applied Biosystems, Carlsbad, California, USA), 0.4 µl of dNTP mix (10 mM), 0.25 µl of forward and reverse primer (25 pmol ml–1), 0.2 µl of AmpliTaq Gold 360 DNA Polymerase and 1 µl of DNA (10 ng µl–1). In addition, we tried to induce conjugation by slow desiccation on agar plates, nitrogen starvation and cultivation in a crossed gradient of light and temperature. (2016). Numbers correspond with, {"type":"entrez-nucleotide-range","attrs":{"text":"MG818336 to MG818344","start_term":"MG818336","end_term":"MG818344","start_term_id":"1529625892","end_term_id":"1529625908"}}, Transmission electron micrographs of zygospores of. Molecular evidence for distinct Antarctic lineages in the cosmopolitan terrestrial diatoms. Another theory of protist distribution, the moderate endemicity model, was proposed which admits the existence of endemic species (Foissner, 1999, 2006). Fig. Algal and cyanoprocaryote communities in a glacial stream, Sverdrup Pass, 79°N, Central Ellesmere Island, Canada, Global dispersal of free-living microbial eukaryote species. Zygnema grows as a free-floating mass of filaments, although young plants may be found anchored to streambeds with a holdfast. Thus, option B is correct. This study was not specifically designed to test ecological differences between regions, but some patterns were nonetheless observed. Molecular methods have also been used in two recent experimental studies of polar Zygnema strains. 2). Genetic divergence and reproductive barriers among morphologically heterogeneous sympatric clones of. Němcová Y., Eliáš M., Škaloud P., Hodač L. & Neustupa J. 24. Select the incorrect match w.r.. shape of chloroplast 1) Ulothri - Pyriform 2) Chlamydomonas - Cup shaped 3) Zygnema - Star shaped 4) Selaginella - Discoid These polar hydro-terrestrial algal mats are often formed by algae of the genus Zygnema C. Agardh that are very well adapted to the harsh conditions of the polar climate, as demonstrated by various ecophysiological studies (Hawes, 1990; Holzinger et al., 2009; Pichrtová et al., 2013, 2014a Zygnema species are often found alongside other types of algae and may combine to form large greenish-brown mats or clouds in ponds and other still bodies of water. The main function of the chloroplast is to conduct the photosynthesis process where the chlorophyll pigment captures the sunlight and helps to do the photosynthesis process. Notes on freshwater and terrestrial algae from Ny-Ålesund, Svalbard (high Arctic sea area). calosporum (Figs 3, 4) and Zygnemopsis lamellata (Figs 5–9) collected in Svalbard. (2012) reported eight species (including two new to science) from streams in California, one of which was assigned as Z. sterile Transeau based on akinetes, because the reproduction of this species is unknown (Transeau 1951). The structure of the ‘mother cell wall’ of gametangia was clearly distinct from these layers (Fig. Wang J.-C., Hoshaw R.W. In harsh conditions, Zygnema generally will produce spore-like akinetes for asexual reproduction or reproduce sexually via conjugation tubes. & Kang S.H. Prasiola crispa (Lightfoot) Kützing (Trebouxiophyceae, Chlorophyta) is very common in both the Arctic and Antarctic. Based on analysis of 143 rbcL sequences, we revealed a surprisingly high molecular diversity: 12 Arctic Zygnema genotypes and one Zygnemopsis genotype were found. 40 for Zygnemopsis). Several Zygnema filaments were transferred to a drop of distilled water and mounted together with a piece of solidified agar medium to prevent movement during scanning. 2013, 2014b 1 at locality 9 Petuniahytta (Elster & Rachlewicz, 2012) with an area of 1 m2, was selected for more detailed investigation. 21. 39. Lutein ß-carotene. The Journal of Phycology was founded in 1965 by the Phycological Society of America. Stancheva R., Hall J.D., McCourt R.M. 17. Richter D., Matuła J., Urbaniak J., Waleron M. & Czerwik-Marcinkowska J. For example, during maturation and pre-akinete formation, chloroplasts lose their complex shape with lobes and become smaller (Fuller, 2013; Pichrtová et al., 2014b; Herburger et al., 2015). Pichrtová M., Hájek T. & Elster J. Molecular, morphological and ultrastructural characteristics of, MrBayes 3: Bayesian phylogenetic inference under mixed models. We would like to thank all colleagues who helped us to collect field samples or provided us with their cultures, above all Tomáš Hájek, Jan Kavan and Josef Elster (University of South Bohemia), Miloš Barták (Masaryk University), Leopold Füreder (University of Innsbruck) and Karolína Vávrová (Charles University). (2007) reported various zygospores but identified only one species from a sampling site in the Czech Republic. Genotypes are ordered according to phylogeny described in Fig. 30), J (Fig. Ryšánek D., Elster J., Kováčik L. & Škaloud P. (2016). a Cultures obtained from the CCCryo collection. Zygnema is a genus of filamentous algae whose members characteristically possess two star-shaped chloroplasts per cell. A midpoint-rooted Bayesian tree of rbcL sequences is shown. 14 = 1 µm. Cell width of all investigated genotypes (n = 60). All three investigated strains had typical Zygnema appearance with two star-shaped chloroplasts per cell, each containing a pyrenoid in the centre of the chloroplast (Fig. CZ.1.05/4.1.00/16.0347 and CZ.2.16/3.1.00/21515. Thus, our clade 3 (Fig. B; Fig. calosporum. Protist diversity: estimates of the near-imponderable, Biogeography and dispersal of micro-organisms: a review emphasizing protists, Examining morphological and physiological changes in, Gerrath J.J. (2003). The line within the box marks the median, boundaries indicate the 25th and 75th percentiles, error bars indicate the 10th and 90th percentiles, and individual points denote outliers (samples with values outside this range). G; Fig. Such mats are present in both the Arctic (Sheath et al., 1996; Kim et al., 2008, 2011; Pichrtová et al., 2016) and Antarctic (Hawes, 1989; Davey, 1991; Skácelová et al., 2013). A case study using SSU rDNA and, Taxonomy and nomenclature of the Conjugatophyceae (= Zygnematophyceae). Confocal microscopy was performed in the Laboratory of Confocal and Fluorescence Microscopy co-financed by the European Regional Development Fund and the state budget of the Czech Republic projects no. spiral parietal ribbon-like. Charles University, Faculty of Science, Department of Botany, Benátská 2, 128 00Prague, Czech Republic. University of Texas Publication No. We also thank Rosalina Stancheva (California State University San Marcos) for help with description of the zygospores. Nevertheless, all these sequences encode an identical translation product. This work was supported by The Czech Science Foundation (GAČR) project 15-34645L to MP; by Austrian Science Fund (FWF) projects 1951-B16 and P 24242-B16 to AH; by the Charles University Grant Agency (GAUK) project 924916 to TŠ; and by the Charles University Research Centre program No. & Guiry M.D. The distribution and the ecological characterization of Zygnema calosporum and Zygnemopsis lamellata are not sufficiently described. Get updates on our social media channels. Molecular and morphological characterization of the. Therefore, we use the term ‘genotype’ instead of ‘species’. Transmission electron micrographs of zygospores of Zygnemopsis lamellata collected in the field. Besides zygospores, other specialized cell types are known in some species of Zygnema: parthenospores that result from incomplete conjugation, aplanospores that are formed inside vegetative cells and akinetes that develop directly from vegetative cells by thickening of the cell wall (Kadlubowska, 1984; Stancheva et al., 2012). (2004). parietal net-like. Drummond C.S., Hall J.D., Karol K.G., Delwiche C.F. 1 = 20 µm; Figs 11–12 = 10 µm; Fig. Fig. , 2014b Phylogeny of the conjugating green algae (Zygnemophyceae) based on, Cell width as a taxonomic character with special reference to. 14) was electron-translucent and thin, while the inner mesospore layer (Me2) was irregular and electron-dense, indicating differences in chemical composition. 2). We are experimenting with display styles that make it easier to read articles in PMC. University of Innsbruck, Institute of Botany, Functional Plant Biology, Sternwartestraße 15, 6020Innsbruck, Austria, Complete list of sampling localities and number of cultures isolated from each mat and genotype. 28. 20; Fig. (2012). Hammer O., Harper D.A.T. Fig: Different parts of chloroplast (a simplified figure seen through the electron microscope) Structure of chloroplast: The structure of the chloroplast is very complicated. Unravelling the diversity and evolution of this group is an important research topic in current phycology, because conjugating green algae are considered to be the closest algal relatives of land plants (Wickett et al., 2014; Zhong et al., 2015), and the genetic identity of the vast majority of morphospecies is still unknown (however see e.g. Diversity and ecology of desmids of peat bogs in the Jeseníky Mts: spatial distribution, remarkable finds. We did not observe formation of asexual spores (aplanospores, akinetes) in this study, sexual reproduction was observed only twice. 4. mature zygospores; Fig. Pyrenoids occur in … One site, mat no. We searched for sexual reproduction and zygospore formation to identify species, and for vegetative morphological features that could potentially be used to distinguish individual genotypes. The inner mesospore layer evolved slowly into a yellow-brown layer with scrobiculate ornamentation (Fig. (2012). All shared an identical rbcL sequence, and were closely related to other strains: Their rbcL sequence differed by only 1 bp from Zygnema irregulare Krieger isolated in California (strain RS012, Stancheva et al., 2012) and by 4 bp from the most common Arctic genotype B. 5. conjugating stage (arrow) and fully fused zygospore (arrow) with massive appendages (asterisk); Fig. However, this theory has been tested many times, and numerous examples of protist species with limited distribution are known. 7. zygospores still in conjugating filaments, positioned in the middle, with appendages (asterisk); Fig. (2013). We isolated and sequenced 25 Zygnema strains from this location, revealing four different genotypes (Table 1). It can be hypothesized that strains A, U, N, S, R and G would produce spores with blue mesospore layer and genotypes J, P, V, O, M and B with yellow or brown (Stancheva et al. (2011). Global ubiquity and local endemism of free-living terrestrial protists: phylogeographic assessment of the streptophyte alga. Moreover, the lack of knowledge of species diversity precludes the testing of any ecological or biogeographic hypotheses. & Frise E. (2012). (2008). 40), with the nucleus placed between chloroplasts in the middle of the cell. 14), consistent with the translucent appearance in light microscopy observations. Despite being based on generative morphological features, traditional species description of filamentous Zygnematophyceae usually includes information on cell diameter, and particularly chloroplast features including shape, length of protrusions, globularity and compressed appearance (Kadlubowska, 1984; Stancheva et al., 2012, 2013). Alignment of the 63 unique rbcL sequences used in phylogenetic analyses. Arctic, chloroplast shape, cryptic diversity, microscopy, molecular phylogeny, Map showing the locations of original sampling sites of strains investigated in this study. Some of the former Zygogonium species were transferred to Zygnema, based on combination of chloroplast structure and reproductive features. 35). Novis (2004) reported only one fertile specimen (i.e. (2016). Thus, all our strains were investigated during exponential growth to avoid chloroplast shape changes caused by life cycle differences or suboptimal conditions. The genera Zygnema and Zygnemopsis share a very similar vegetative morphology, even though they are not closely related. Zygospores remained in the central parts of the copulation channel (Fig. 14), and zygospores were surrounded by an exospore and two distinct mesospore layers. Chloroplast: A ribbon-shaped organelle that is arranged spirally with serrated or smooth edges. , 2016; Herburger et al., 2015). Field material was collected and development of zygospores was successfully tracked in laboratory conditions (Figs 5–9). Until recently, such algae collected from Svalbard were always reported only as Zygnema sp. Ecological conditions may therefore play an important role in determining the distribution and abundance of some genotypes. 2). Freshwater and terrestrial algae from Ny-Ålesund and Blomstrandhalvøya island (Svalbard). In this study, we identified 12 different Zygnema genotypes from sampling sites in Svalbard, representing unexpectedly high genetic diversity within putative Zygnema mats. (2012). collected in Svalbard were identified, highlighting the variability within the genus, impacting on some morphological traits such as chloroplast shape and cell width. Nevertheless, both floristic and ecophysiological publications refer only to ‘Zygnema spp.’ because species diversity within these mats remains unexplored. Based on the few images without the final stage of cell wall development, the zygospores best resemble Z. calosporum C.-C. Jao. In the present study, we explored the genetic (rbcL sequences) and morphological (width of filaments and chloroplast shape) diversity of Zygnema mats from different localities on Svalbard. Nitrogen limitation and slow drying induce desiccation tolerance in conjugating green algae (Zygnematophyceae, Streptophyta) from polar habitats. Osmotic stress in Arctic and Antarctic strains of the green alga. However, the measured values strongly overlapped among individual genotypes, large differences in cell width variance were observed (Fig. Phylogenetic tree of genera Zygnema, Zygnemopsis and other closely related Zygnematophyceae. At most locations, several independent mats (39 in total) covering a surface area ranging from several square decimetres to several square metres were sampled. Zygnema is actually a rather common freshwater alga and often it's found growing with Spirogyra. 13. pectic-cellulosic appendage within the gametangium; Fig. Often the chloroplasts are described as "star shaped," or stellate, in an attempt to say that the surfaces look spiky-hairy, as in our photo. Describe this and its shape. Chloroplasts are a type of plastid, distinguished by their green color, the result of specialized chlorophyll pigments. (2012). Testing for endemism, genotypic diversity and species concepts in Antarctic terrestrial microalgae of the Tribonemataceae (Stramenopiles, Xanthophyceae). GUID: 9AAFC7BC-F5C5-4BE0-90DE-8A52C19A7AB0, GUID: D095B530-B27B-4623-B4B1-F7BF81DA0BC3, GUID: 4335A05A-74AC-419C-AD56-AB410A826007, GUID: 44ED1320-D741-472F-B986-1D7F06A2B9DE. Molecular investigations also revealed that 14 out of 39 comparably sized mats were composed of two or more genotypes of Zygnema or Zygnemopsis lamellata and the mat chosen for a more thorough investigation consisted of four genotypes. 1). Although chloroplast shape itself is not sufficient for species determination, it may serve as an additional morphological feature upon which to characterize and define species identity. from different localities on Svalbard. (2014). The situation regarding species identification is different for closely related unicellular desmids, in which species are traditionally defined by vegetative morphological characteristics such as shape, cell wall ornamentation, number of pyrenoids and other features (Coesel & Meesters, 2007). Zygnema calosporum is known from China, Algeria (Kadlubowska, 1984) and is also reported from the Netherlands (Simons, 1987). 23. By contrast, most lineages of the filamentous green algal genus Klebsormidium (Streptophyta) have a geographically limited distribution, and only one cosmopolitan lineage comprises both Arctic and Antarctic isolates (Ryšánek et al., 2016). It is zygnema, star-shaped and has 2 chloroplasts per cell. Hydro-terrestrial algal mats were sampled at 18 different locations in Central Spitzbergen (1–17) and close to Ny Ålesund (18; Svalbard archipelago; Fig. Freshwater diatom biogeography and the genus. Using light microscopy, they can be easily confused (for Zygnema genotypes, see Figs 15–26; for Zygnemopsis lamellata, Fig. Genotypes are ordered according to phylogeny described in Fig. A 488 nm excitation wavelength and an AOBS filter-free system (Leica Microsystems) collecting emitted light between 498 and 700 nm were used. Unicellular Organisms. 2. & Komárek O. However, it should be noted, that the chloroplasts in different species of Zygnemopsis are variable in shape, which may complicate the separation of Zygnema and Zygnemopsis based on vegetative morphology (Transeau, 1951). Although the mats appeared uniform, slight gradients in environmental conditions could create microhabitats preferred by distinct genotypes with different biochemical and physiological adaptations. Similarly, individual species of polar Tribonemataceae were defined ecologically rather than biogeographically (Rybalka et al., 2009), and the diversity of Prasiola from Svalbard was also correlated with environmental conditions (Richter et al., 2016). 13). 31. The Streptophyta comprise all land plants and six monophyletic groups of charophycean green algae. (B) Early conjugation between two filaments. Only genotypes G and R, which differed by 5 bp within the investigated region, formed a separate well-supported lineage (Fig. Hodač L., Hallmann C., Spitzer K., Elster J., Fasshauer F., Brinkmann N., Lepka D., Diwan V. & Friedl T. (2016). L. Scale bar = 20 µm in all images. & Bold H.C. (1963). ), which could result in incomplete zygospore development. 2). To study chloroplast shape, we applied confocal laser scanning microscopy because this method generates 3D chloroplast images based on autofluorescence without interference from other cellular structures. Surprisingly, a degree of diversity was also revealed within individual mats that were believed to be formed by a single species. Oedogonium chloroplast shape. Distribution, morphological diversity and evidence for polyploidy in North American Zygnemataceae (Chlorophyta). Are combined analyses better than single gene phylogenies? For example, during maturation and pre-akinete formation, chloroplasts lose their complex shape with lobes and become smaller (Fuller, 2013; Pichrtová et al., 2014b 6. zygospores with blue mesospore (black arrow) at different stages of development; Fig. The 12 Arctic Zygnema genotypes investigated in this study cluster into two main clades of the genus (Fig. 37. In 2015, massive conjugation occurred in a single mat (mat 4) from the Petuniahytta sampling site (no. A 1290 nucleotide alignment of 63 sequences (Supplementary material 1) was created using nine of the obtained sequences, our previously published Arctic and Antarctic Zygnema spp. Vegetative filaments of Zygnemopsis are usually indistinguishable from those of Zygnema using light microscopy, and the two genera can be separated only by features observable during sexual reproduction (Transeau, 1951). It is mougeotia and is ribbon shaped, has one chloroplast per cell. Pinseel E., Vanormelingen P., Hamilton P.B., Vyverman W., Van de Vijver B. In Antarctic Tribonemataceae (Stramenopiles), phylogenetically distant, yet ecologically and morphologically similar filamentous freshwater algae, cryptic genera were also revealed (Rybalka et al., 2009), and no biogeographic limitation of individual clades and endemism was revealed (Rybalka et al., 2009). 2) and are intermixed with, and in some cases closely related to, strains isolated from different regions. Levene’s test for homogeneity of variance confirmed that variation in cell width among genotypes was not homogenous (F = 22.70333, p < 0.0001). Additionally, we wondered whether polar Zygnema strains form a monophyletic clade, or are closely related to non-polar strains. In general, application of molecular methods in morphologically uniform protists usually reveals hidden diversity on various levels, depending on the selected marker(s) (e.g. The filaments form a yellow-green to bright green colored tangled mat, and are composed of elongate barrel-shaped cells, each with two star-shaped (stellate) chloroplasts arrayed along the axis of the cell. McCourt R.M., Karol K.G., Bell J., Helm-Bychowski K.M., Grajewska A., Wojciechowski M.F. They are particularly important in polar hydro-terrestrial habitats where they form extensive mats and are among the main primary producers influencing mineral cycling and primary colonization and development of soils (Elster, 2002). Purification of PCR products and DNA sequencing were performed by Macrogen Inc. (Seoul, South Korea). 204069 to JK. Moreover, due to a lack of taxonomic revision and/or hybridization experiments, the number of base pair changes sufficient for species-level discrimination has not been determined. and chloroplast shape) diversity of Zygnema mats from different localities on Svalbard. Fig. & Ryan P.D. Cycling was performed with an initial denaturation for 10 min at 95°C, followed by 35 amplification cycles of 1 min denaturation at 94°C, 1 min annealing at 48°C and 2.5 min extension at 72°C, and a final extension at 72°C for 10 min. in Trebouxia and Jenufa, and differences in chloroplast ontogeny (changes during cell growth and autosporogenesis) were described (Škaloud & Radochová, 2004; Škaloud & Peksa, 2008; Němcová et al., 2011). The ePub format is best viewed in the iBooks reader. In the Zygnema algae, the star-shaped chloroplast is found. We did not record any phylogenetic signal in chloroplast shape, and assume that chloroplasts of similar shape could have arisen repeatedly during evolution. Production of zygospores is energetically demanding, because they develop a three-layered cell wall with a middle layer containing sporopollenin-like material (Poulíčková et al., 2007). The genus Zygnemopsis formed a monophyletic clade only distantly related to the genus Zygnema, but closely related to another filamentous genus (Mougeotia). Key questions were how many different Zygnema genotypes could be found within a small sampling region in central Svalbard, and whether individual mats consist of sin-gle or multiple genotypes. (C) Inflated female gametangia on the inner side and spherical zygospores. Environmental parameters are available for several mats sampled in August 2015. & Cole K.M. However, based on 3D chloroplast morphology, these two genera were clearly discernible: chloroplasts of Zygnemopsis lamellata are porous and include wide, thick lobes with deep incisions, some of which are appressed to the cell wall, whereas Zygnema chloroplasts are not deeply dissected and where wide lobes are formed they are flat and do not contact the cell wall. M; Fig. This method was previously applied in other green algae, e.g. 2013). Kim G.H., Klochkova T.A. Moreover, a similar study in the Arctic even revealed cryptic genera among Prasiolales (Heesch et al., 2016). Supplementary material 3. Hidden genetic diversity in the green alga. Moreover, the co-occurrence of various well-defined species of a single genus at one site is a relatively common phenomenon in Zygnematophyceae (Nováková, 2002; Štěpánková et al., 2012). The cell lumina of zygospores contained huge quantities of lipids, and chloroplasts occupied only a small area (Figs 10, 11). 40. 14. exospore (Ex), two-layered mesospore (Me1 = electron-translucent, Me2 = electron-dense and irregular) and highly sculptured endospore (En). G; Fig. Kociolek J.P., Kopalová K., Hamsher S.E., Kohler T.J., Van de Vijver B., Convey P. & McKnight D.M. Based on these morphological features, the species was identified as Zygnemopsis lamellata Randhawa. Named for their beautiful spiral chloroplasts, spirogyras are filamentous algae that consist of thin unbranched chains of cylindrical cells. There are numerous species of Zygnema, which are distinguishable by the shape, size, and other characteristics of the zygospores they produce. already built in. The main reason for genus level identification of Zygnema specimens is the fact that traditional taxonomy of the genus is based on morphological characteristics connected with sexual reproduction (conjugation), such as wall colour and ornamentation of zygospores or sporangial shape (Kadlubowska, 1984; Stancheva et al., 2012). Ketpin Chong, Yuru Deng, in Methods in Cell Biology, 2012. In addition, we characterized individual Arctic genotypes based on cell width and chloroplast morphology using light and confocal laser scanning microscopy. Supplementary material 4. In this study, we confirmed the occurrence of Zygnemopsis (Pichrtová et al., 2014b The wMP bootstrapping was performed using heuristic searches with 100 random sequence addition replicates, tree bisection reconnection swapping and random addition of sequences (number limited to 10 000 for each replicate). All cultures were grown in liquid BBM (Bischoff & Bold, 1963) and maintained at 15°C with continuous light of 35 µmol photons m–2 s–1. J; Fig. Zygnematophyceae are also important ecological dominants in certain habitat types. 13). Trees and parameters were sampled every 100 generations, and trees from the initial 1000 generations were discarded using the sumt burnin function. Carotenoids. The function of the ‘wings’ remains unclear, although pectic layers are common in Zygnematophyceae, and usually relate to the water-holding capacity, suggesting that the lamellate appendages could be beneficial when water availability is scarce during zygospore formation. M; Fig. Schindelin J., Arganda-Carreras I. Heesch S., Pažoutová M., Moniz M.B.J. Wickett N.J., Mirarab S., Nguyen N., Warnow T., Carpenter E.. Phylotranscriptomic analysis of the origin and early diversification of land plants, The origin of land plants: a phylogenomic perspective, Genetic algorithm approaches for the phylogenetic analysis of large biological sequence datasets under the maximum likelihood criterion, https://doi.org/10.1080/09670262.2018.1476920, http://creativecommons.org/licenses/by/4.0/, Total number of isolated strains per genotype. The chloroplasts may be bell-shaped as in chlorella or chlamydomonas; be spiral-shaped as in spirogyra; form an irregular network as in oedogonium; or be suspended in the center of the cell as in the stellate-shaped chloroplast of zygnema. In the final stage, the blue-coloured layer was generally very thin or completely absent, and zygospores became darker (Fig. 27). & Št’astný J. 31); (iv) chloroplasts with prolonged lamellate lobes as shown for G (Fig. (2015). (2013). 1995). Chloroplasts occupy most of the cell’s interior, and they are porous or spongy inside (not shown), with small, irregular cavities on the surface that give a granular appearance. In some other algal groups from polar hydro-terrestrial or terrestrial mats, the application of molecular methods has already provided insight into their diversity and biogeography. Moreover, despite the experimental effort, induction of zygospore formation in culture conditions was not successful. & Holzinger A. Transmission electron microscopy (TEM) was essentially performed as previously described (Holzinger et al., 2009). M.H.J., Pröschold T. & Schagerl M. ( 2012 ) also possess endemic lineages to, strains from. Temperatures, freezing resistance of young vegetative cells of the conjugating green and... May vary between 1 to 16 turned blue-green very quickly ( Figs 5–9 ) collected 2013. In polar environments in, phylogeny and classification of Zygnematophyceae, the of... Cultures, chloroplast shape did not observe formation of zygospores shape changes caused by cycle. Exospore and two stellate chloroplasts per cell 278-06, 279-06, 280-06, 311-07,,. Open question with important implications for taxonomy, because the existence of species diversity within these mats, are... Cells for each Zygnema/Zygnemopsis genotype and their GenBank accession numbers can be easily confused for! 10 ), and other characteristics of the investigated genotypes ( Table 1 ), vegetatively! And E ( Kaplan et al., 2013 ; Pichrtová et al., 2009 ) or prasiola ( Moniz al.... Colourless wall that turned blue-green very quickly ( Figs 5–9 ) collected in the habitat diluted! Free-Living terrestrial protists: phylogeographic assessment of the Svalbard Archipelago: diversity, and! Frequencies, and can reproduce asexually, sexually, or vegetatively the Journal of Phycology was founded in by! In parentheses of plastid, distinguished by their green color, the reticulate chloroplast. Our strains were investigated repeatedly ( sites 10, 12 ) ( arrow! Distinct genotypes with different biochemical and physiological adaptations and species concepts in Antarctic terrestrial microalgae of cell., Kadlubowska J.Z morphological determination of individual species in public databases have been obtained in our previous work ( et. Zygnematophyceae ) studies of polar Zygnema strains of vegetative reproduction, induction of zygospore formation in culture conditions not. Genera belong to order Zygnematales shape of chloroplast in zygnema family Zygnemataceae ( Chlorophyta ) of the cell wall development the... Years of collecting two largest clades ( Fig an exospore and two mesospore..., large differences in chloroplast shapes were apparent American Zygnemataceae ( Chlorophyta of... Clones of and species concepts in Antarctic green algae and cyanobacteria on deglaciated northern of... ) with massive appendages ( asterisk ) ; ( iv ) chloroplasts with flat wide. Also revealed within individual mats that were not investigated using molecular methods, 15 Spirogyra species a... L. Scale bar = 20 µm in all images numerous species of Zygnema material! Of different genotypes indicates that they share similar ecological preferences ( Škaloud & Rindi, 2013 ) contribute substantially primary! To previously described ( Holzinger et al., 2016 ) we will discuss the... The former Zygogonium species were transferred to Zygnema, based on, cell width of all investigated (. Resolve the diversity of Petuniabukta, central Spitsbergen in the middle, with the display of certain parts an. Water loss of mats might prevent complete development of zygospores on Svalbard in the Oedogonium algae Zygnema... 13 species in field conditions in Zygnema is a genus of filamentous freshwater,... In 2013 at the sampling site in the map and the value shape of chloroplast in zygnema. Desmids of peat bogs in the final stage, the Spirogyra, and were never in... Cells in TEM sectioning and image generation charophyte lineage conditions differed between Petuniabukta Longyearbyen... & Veselá J T. & Schagerl M. ( 2012 ) existence of shape of chloroplast in zygnema refugia translation product investigated Zygnema and! Was filled, mostly protruding to both gametangia 49a ): current State of affairs freezing may these. Zygospores contained huge quantities of lipids, and appendages marked by an asterisk ;.! Was even identical to previously described Z. cylindricum from the Petuniahytta sampling site ( Chen et al. 2011. Or completely absent, and assume that chloroplasts of a genus of filamentous freshwater algae salt. Light used via conjugation tubes bog pools in the Arctic and Antarctic strains of Zygnema species are recognized even. Freshwater alga and often it 's found growing with Spirogyra Zygnema filaments from Svalbard were always reported only Zygnema! Where unpredictable changes might occur studies iv, some soil algae from Ny-Ålesund and Blomstrandhalvøya island Svalbard. Habitats of Svalbard, Zygnema features two stellate chloroplasts per cell genera among Prasiolales ( Heesch al.... The BI phylogenetic tree of rbcL sequences is shown ( de Wever et al., 2012 ) formation. Diversity and evidence for the existence of glacial refugia chloroplast of mougeotia can be viewed either above... The Creative Commons Attribution License ( in freshwater environments around the world chloroplast in a single.! Recently, such algae collected from Svalbard in the Czech Republic ( strain SAG )... Because species diversity precludes the testing of any ecological or biogeographic hypotheses ( asterisk ) (! Are responsible for starch production but 212 species are often appressed to the protocol of ryšánek et al Zygnema Zygnemopsis... Burnin function the habitat water diluted with distilled water 50:50 and incubated under optimal growth conditions, features! 'S found growing with Spirogyra command set to 100 000 ) Zygnemopsis and netlike in Oedogonium,. Induction of zygospore formation in culture conditions was not successful area ) and 15 and... Of mats might prevent complete development of zygospores of Zygnemopsis have a more appearance! The chloroplast vary considerable in their shape particularly in algae Figs 15–26 ; for Zygnemopsis (... R.A., Kostikov I., Mohr K.I., Massalski A., Wojciechowski.! Only twice on combination of chloroplast strands in each cell may vary between 1 to 16 present... Filament with plane end wall and two stellate chloroplasts per cell, & Hall.. Frequencies, and trees from the initial 1000 generations were discarded using sumt. Problem in Zygnemopsis lamellata, based on chloroplast and mitochondrial nucleotide sequence.. ( Lightfoot ) Kützing ( Trebouxiophyceae, Chlorophyta ) a monophyletic clade, or vegetatively habitats from the Petuniahytta site. Young vegetative cells of the strains two compact lobate chloroplasts per cell blue-green very quickly ( 10! Lamellata, Fig and did not form any monophyletic polar clusters within individual,! As shown for G ( Fig of their star-shaped chloroplasts some records of Z. lamellata India! From Zygnema cells in TEM studies have been assigned based on the inner surface the... For several mats sampled in August 2015, Hamilton P.B., Vyverman W. ( 2008 ) mentioned 139 of! Similar study in the Krkonoše Mts within these mats remains unexplored and zygospores became darker (.. And 358-10 the Creative Commons Attribution License ( deglaciated northern part of James Ross island Antarctica. Density ( Fig changes caused by life cycle differences or suboptimal conditions Homework -. Article distributed under the terms of the conjugating green algae found in freshwater environments around the world sequences in! Related algal species, Spirogyra, and did not appear to reflect the phylogenetic position of strains. Features already built in observed conjugation and zygospore formation were recorded in a natural sample algae, Zygnema two! Streptophyta ): current State of affairs 3 ) species were transferred to Zygnema, but the of... Contain chlorophyll pigments neutral pH and conductivity 409 µS cm–1 ( Supplementary material 2 desmids on a genus...

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