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1.
Cozzolino  Salvatore  Caputo  Paolo  De Castro  Olga  Moretti  Aldo  Pinto  Gabriele 《Hydrobiologia》2000,433(1-3):145-151
Cyanidium caldarium, Cyanidioschyzon merolae and Galdieria sulphuraria are three unicellular algae characteristic, of acid thermal environments. Recently, on the basis of morphological characters, three new species of Galdieria (G. partita, G. daedala, G. maxima ) isolated from acid-thermal springs in Russia have been instituted. A selected region of rbcL and the sequence of the intergenic spacer between the rbcL and rbcS have been amplified and sequenced from different Galdieria species and strains, in order to define molecular relationship among these interesting algae. The obtained cladogram shows that Cyanidium caldarium and Cyanidioschyzon merolae form a sister group which, in turn, is in a sister group relationship with Galdieria. This last genus is divided in two clades, one of which includes G. sulphuraria accessions from Naples (Italy), California, and Yellowstone and the other one includes G. sulphuraria accessions from Java (Indonesia) and from the Russian species. These results support the status of the genus Galdieria and suggest that G. daedala, G. maxima and G. partita are three very similar strains of G. sulphuraria; the rbcL variation within Galdieria accessions has a pattern which is broadly connected to the geographial distribution. The data obtained from the intergenic rbcL-rbcS spacer partly confirm those from the rbcL analysis.  相似文献   

2.
To research the adaptive evolution and coevolution of the rbcL gene in the genus Galdieria, 36 sequences were selected. The bioinformatics of proteins encoded by rbcL genes of Galdieria were analyzed, and phylogenetic trees were constructed by the maximum-likelihood method. Then, adaptive evolution and coevolution were analyzed. The phylogenetic tree showed that the inner groups were clustered into four branches, in which the sequences of Galdieria maxima were divided into two small branches, and the posterior probability of each branch is above 94.9%. Eleven reliable positive selection sites were detected in the branched-site model, indicating that the rbcL protein-coding gene of Galdieria underwent adaptive evolution to adapt to extreme environments. Site 269 F is located in the loop 6 domain, while sites 272 D and 273 W are located in the 6-helix structure. Many coevolution pairs were detected, which were closely related to the hydrophobic and molecular weight correlation values of amino acids. The results are helpful to research the evolution process of freshwater red algae, to explore the changes of its essential genes and protein functions to adapt to different environmental pressures, and to understand the close relationship between amino acids in proteins and the molecular mechanism of evolution.  相似文献   

3.
Few species in the genus Grateloupia have been investigated in detail with respect to the development of the auxiliary cell ampullae before or after diploidization. In this study, we document the vegetative and reproductive structures of two new species of Grateloupia, G. taiwanensis S.‐M. Lin et H.‐Y. Liang sp. nov. and G. orientalis S.‐M. Lin et H.‐Y. Liang sp. nov., plus a third species, G. ramosissima Okamura, from Taiwan. Two distinct patterns are reported for the development of the auxiliary cell ampullae: (1) ampullae consisting of three orders of unbranched filaments that branch after diploidization of the auxiliary cell and form a pericarp together with the surrounding secondary medullary filaments (G. taiwanensis type), and (2) ampullae composed of only two orders of unbranched filaments in which only a few cells are incorporated into a basal fusion cell after diploization of the auxiliary cell and the pericarp consists almost entirely of secondary medullary filaments (G. orientalis type). G. orientalis is positioned in a large clade based on rbcL gene sequence analysis that includes the type species of Grateloupia C. Agardh 1822 , Gfilicina. G. taiwanensis clusters with a clade that includes the generitype of Phyllymenia J. Agardh 1848 , Ph. belangeri from South Africa; that of Prionitis J. Agardh 1851 , Prlanceolata from Pacific North America; and that of Pachymeniopsis Y. Yamada ex Kawab. 1954, Palanceolata from Japan. A reexamination of the type species of the genera Grateloupia, Phyllymenia, Prionitis, and Pachymeniopsis is required to clarify the generic and interspecific relationships among the species presently placed in Grateloupia.  相似文献   

4.
The Cyanidiophyceae, an extremophilic red algal class, is distributed worldwide in extreme environments. Species grow either in acidic hot environments or in dim light conditions (e.g., “cave Cyanidium”). The taxonomy and classification systems are currently based on morphological, eco-physiological, and molecular phylogenetic characters; however, previous phylogenetic results showed hidden diversity of the Cyanidiophyceae and suggested a revision of the classification system. To clarify phylogenetic relationships within this red algal class, we employ a phylogenomic approach based on 15 plastomes (10 new) and 15 mitogenomes (seven new). Our phylogenies show consistent relationships among four lineages (Galdieria, “cave Cyanidium”, Cyanidium, and Cyanidioschyzon lineages). Each lineage is distinguished by organellar genome characteristics. The “cave Cyanidium” lineage is a distinct clade that diverged after the Galdieria clade but within a larger monophyletic clade that included the Cyanidium and Cyanidioschyzon lineages. Because the “cave Cyanidium” lineage is a mesophilic lineage that differs substantially from the other three thermoacidophilic lineages, we describe it as a new order (Cavernulicolales). Based on this evidence, we reclassified the Cyanidiophyceae into four orders: Cyanidiales, Cyanidioschyzonales, Cavernulicolales ord. nov., and Galdieriales ord. nov. The genetic distance among these four orders is comparable to, or greater than, the distances found between other red algal orders and subclasses. Three new genera (Cavernulicola, Gronococcus, Sciadococcus), five new species (Galdieria javensis, Galdieria phlegrea, Galdieria yellowstonensis, Gronococcus sybilensis, Sciadococcus taiwanensis), and a new nomenclatural combination (Cavernulicola chilensis) are proposed.  相似文献   

5.
Based upon COI‐5P, LSU rDNA, and rbcL sequence data and morphological characteristics, six new members of the noncalcified crustose genus of red algae Ethelia are described in a new family, Etheliaceae (Gigartinales), sister to the recently described Ptilocladiopsidaceae. The novel species are described from subtropical to tropical Atlantic and Indo‐Pacific Ocean basins; E. mucronata sp. nov. and E. denizotii sp. nov. from southern and northern Western Australia respectively, E. wilcei sp. nov. from the Cocos (Keeling) Islands of Australia, E. suluensis sp. nov. from the Philippines, E. umbricola sp. nov. from Bermuda and E. kraftii sp. nov. from Lord Howe Island, Australia. The generitype, Ethelia biradiata, originally reported from the Seychelles, Indian Ocean, is added to the Western Australian flora.  相似文献   

6.
On the basis of comparative morphology and phylogenetic analyses of rbcL and LSU rDNA sequence data, a new genus, Gayliella gen. nov., is proposed to accommodate the Ceramium flaccidum complex (C. flaccidum, C. byssoideum, C. gracillimum var. byssoideum, and C. taylorii), C. fimbriatum, and a previously undescribed species from Australia. C. transversale is reinstated and recognized as a distinct species. Through this study, G. flaccida (Kützing) comb. nov., G. transversalis (Collins et Hervey) comb. nov., G. fimbriata (Setchell et N. L. Gardner) comb. nov., G. taylorii comb. nov., G. mazoyerae sp. nov., and G. womersleyi sp. nov. are based on detailed comparative morphology. The species referred to as C. flaccidum and C. dawsonii from Brazil also belong to the new genus. Comparison of Gayliella with Ceramium shows that it differs from the latter by having an alternate branching pattern; three cortical initials per periaxial cell, of which the third is directed basipetally and divides horizontally; and unicellular rhizoids produced from periaxial cells. Our phylogenetic analyses of rbcL and LSU rDNA gene sequence data confirm that Gayliella gen. nov. represents a monophyletic clade distinct from most Ceramium species including the type species, C. virgatum. We also transfer C. recticorticum to the new genus Gayliella.  相似文献   

7.
Using sequences of 5′ region of the cytochrome oxidase subunit 1 gene, large subunit rDNA, and ribulose‐1,5‐bisphosphate carboxylase/oxygenase large subunit gene as genetic markers to elucidate their phylogenetic positions, six unknown species from Western Australia, Tasmania, Lord Howe Is., and Norfolk Is. cluster with Meredithia in the Kallymeniaceae (Gigartinales), and are described as new members of this previously monospecific genus. Specimens from Bermuda referable to Kallymenia limminghei Mont. in the 20th century also clustered with this genetic grouping, not with the generitype of Kallymenia. The Bermudian specimens are further shown to be morphologically distinct from the type of K. limminghei (Guadeloupe, Caribbean Sea) and are described as a new species, Meredithia crenata. Using these Indo‐Pacific and Bermudian collections, our analyses further show that Psaromenia is closely related to Meredithia, and that Cirrulicarpus nanus sensu stricto should be returned to Meredithia.  相似文献   

8.
A novel Gram-negative and rod-shaped bacterium, designated N8T, was isolated from tidal flat sediment. Phylogenetic analysis based on 16S rRNA gene sequences showed that N8T strain is associated with the family Phyllobacteriaceae: two uncultured clones (98.4 and 99.8% 16S rRNA gene sequence similarity) and the genus Mesorhizobium (≤97.0%). The novel strain formed a separate clade with uncultured clones in the phylogenetic tree based on 16S rRNA gene sequences. Cellular fatty acid profiles predominately comprised C18:1 ω7c and C19:0 cyclo ω8c. The major isoprenoid quinone is ubiquinone-10 and genomic DNA G+C content is 53.4 mol%. The polyphasic taxonomic study indicates that the novel strain N8T represents a novel species of the new genus in the family Phyllobacteriaceae, named Aliihoeflea aestuarii. The type strain is N8T (= KCTC 22052T= JCM 15118T= DSM 19536T).  相似文献   

9.
Cryptomonads are a ubiquitous and diverse assemblage of aquatic flagellates. The relatively obscure genus Hemiselmis includes some of the smallest of these cells. This genus contained only two species until 1967, when Butcher described seven new marine species mainly on the basis of observations with the light microscope. However, from these seven taxa, only H. amylifera and H. oculata were validly published. Additionally, the features Butcher used to distinguish species have since been questioned, and the taxonomy within Hemiselmis has remained clouded due to the difficulty in unambiguously applying his classification and validating many of his species. As a result, marine strains are often placed into one of three species—H. rufescens Parke, H. virescens Droop, or the invalid H. brunnescens Butcher—based on cell color alone. Here we applied microscopic and molecular tools to 13 publicly available Hemiselmis strains in an effort to clarify species boundaries. SEM failed to provide sufficient morphological variation to distinguish species of Hemiselmis, and results from LM did not correlate with clades found using both molecular phylogenetic and nucleomorph genome karyotype analysis, indicating a high degree of morphological plasticity within species. On the basis of molecular characters and collection geography we recognize four new marine species of HemiselmisH. cryptochromatica sp. nov., H. andersenii sp. nov., H. pacifica sp. nov., and H. tepida sp. nov.—from the waters around North America.  相似文献   

10.
Morphological, anatomical, and molecular sequence data were used to assess the establishment and phylogenetic position of the genus Wilsonosiphonia gen. nov. Phylogenies based on rbcL and concatenated rbcL and cox1 loci support recognition of Wilsonosiphonia gen. nov., sister to Herposiphonia. Diagnostic features for Wilsonosiphonia are rhizoids located at distal ends of pericentral cells and taproot‐shaped multicellular tips of rhizoids. Wilsonosiphonia includes three species with diagnostic rbcL and cox1 sequences, Wilsonosiphonia fujiae sp. nov. (the generitype), W. howei comb. nov., and W. indica sp. nov. These three species resemble each other in external morphology, but W. fujiae is distinguished by having two tetrasporangia per segment rather than one, W. indica by having abundant and persistent trichoblasts, and W. howei by having few and deciduous trichoblasts.  相似文献   

11.
We examined the molecular phylogeny and ultrastructure of Chlorogonium and related species to establish the natural taxonomy at the generic level. Phylogenetic analyses of 18S rRNA and RUBISCO LSU (rbcL) gene sequences revealed two separate clades of Chlorogonium from which Chlorogonium (Cg.) fusiforme Matv. was robustly separated. One clade comprised Cg. neglectum Pascher and Cg. kasakii Nozaki, whereas the other clade included the type species Cg. euchlorum (Ehrenb.) Ehrenb., Cg. elongatum (P. A. Dang.) Francé, and Cg. capillatum Nozaki, M. Watanabe et Aizawa. On the basis of unique ultrastructural characteristics, we described Gungnir Nakada gen. nov. comprising three species: G. neglectum (Pascher) Nakada comb. nov., G. mantoniae (H. Ettl) Nakada comb. nov., and G. kasakii (Nozaki) Nakada comb. nov. We also emended Chlorogonium as a monophyletic genus composed of Cg. euchlorum, Cg. elongatum, and Cg. capillatum. Because Cg. fusiforme was distinguished from the redefined Chlorogonium and Gungnir by the structure of its starch plate, which is associated with pyrenoids, we reclassified this species as Rusalka fusiformis (Matv.) Nakada gen. et comb. nov.  相似文献   

12.
An actinomycete strain, designated YIM 60475T, was isolated from the roots of Maytenus austroyunnanensis and was characterized by using a polyphasic approach. The strain was determined to belong to the genus Streptomyces, based on its phenotypic and phylogenetic characteristics. The strain produced spiral spore chains on aerial mycelium. The cell wall contained ll-diaminopimelic acid. Whole-cell hydrolysates contained galactose, glucose, and xylose. The phospholipid was type II. The DNA G+C content of the type strain was 73.3 mol%. DNA–DNA hybridization and comparison of physiological and chemical characteristics suggested that strain YIM 60475T is a new Streptomyces species, for which the name Streptomyces mayteni sp. nov. is proposed. The type strain is YIM 60475T (=CCTCC AA 207005T = KCTC 19383T). Hua-Hong Chen and Sheng Qin contributed equally to this work.  相似文献   

13.
14.
We confirmed the monophyly of the Agaraceae based on phylogenetic analyses of six mitochondrial and six chloroplast gene sequences from Agarum, Costaria, Dictyoneurum, and Thalassiophyllum species, as well as representative species from other laminarialean families. However, the genus Agarum was paraphyletic, comprising two independent clades, A. clathratum/A. turneri and A. fimbriatum/A. oharaense. The latter clade was genetically most closely related to Dictyoneurum spp., and morphologically, the species shared a flattened stipe bearing fimbriae (potential secondary haptera) in the mid‐ to upper portion. The phylogenetic position of Thalassiophyllum differed between the two datasets: in the chloroplast gene phylogeny, Thalassiophyllum was included in the A. clathratum/A. turneri clade, but in the mitochondrial gene phylogeny, it formed an independent clade at the base of the Agaraceae, the same position it took in the phylogeny when the data from both genomes were combined despite a larger number of bp being contributed by the chloroplast gene sequences. Considering the remarkable morphological differences between Thalassiophyllum and other Agaraceae, and the molecular support, we conclude that Thalassiophyllum should be reinstated as an independent genus. Dictyoneurum reticulatum was morphologically distinguishable from D. californicum due to its midrib, but because of their close genetic relationship, further investigations are needed to clarify species‐level taxonomy. In summary, we propose the establishment of a new genus Neoagarum to accommodate A. fimbriatum and A. oharanese and the reinstatement of the genus Thalassiophyllum.  相似文献   

15.
A thermophilic, rod-shaped, motile, Gram-positive, spore-forming bacterium strain 70BT was isolated from a geothermally active underground mine in Japan. The temperature and pH range for growth was 50–81°C (optimum 71°C) and 6.2–9.8 (optimum pH 7–7.5), respectively. Growth occurred in the presence 0–2% NaCl (optimum 1% NaCl). Strain 70BT could utilize glucose, fructose, mannose, mannitol, pyruvate, cellobiose and tryptone as substrates. Thiosulfate was used as electron acceptor. Major whole-cell fatty acids were iso-C15:0, C16:0 DMA (dimethyl acetal), C16:0 and anteiso-C15:0. The G+C mol% of the DNA was 44.2%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the closest relatives of strain 70BT were Thermosediminibacter oceani DSM 16646T (94% similarity) and Thermosediminibacter litoriperuensis DSM 16647 (93% similarity). The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain 70BT represents a novel species in a new genus, for which the name Thermovorax subterraneus gen. nov., sp. nov. is proposed. The type strain of Thermovorax subterraneus is 70BT (=DSM 21563 = JCM 15541).  相似文献   

16.
A novel actinobacterium, designated strain MSW-19T, was isolated from a seawater sample in Republic of Korea. Cells were aerobic, Gram-positive, non-endospore-forming, and non-motile cocci. Colonies were circular, convex, opaque, and vivid yellow in colour. A phylogenetic tree based on 16S rRNA gene sequences exhibited that the organism formed a distinct clade within the radius encompassing representatives of the family Propionibacteriaceae. The phylogenetic neighbors were the type strains of the genera Friedmanniella, Microlunatus, Micropruina, Propionicicella, and Propionicimonas. Levels of 16S rRNA gene sequence similarity between the isolate and members of the family were less than 95.3%. The cell wall peptidoglycan of the organism contained LL-diaminopimelic acid as the diagnostic diamino acid. The isolate contained MK-9(H4) as the predominant menaquinone, ai-C15:0 as the major fatty acid and polar lipids including phosphatidylglycerol, phosphatidylethanolamine, and an unknown phospholipid. The G+C content of the DNA was 69.6 mol%. On the basis of the phenotypic and phylogenetic data presented here, the isolate is considered to represent a novel genus and species in the family Propionibacteriaceae, for which the name Ponticoccus gilvus gen. nov., sp. nov. is proposed. The type strain is strain MSW-19T (= KCTC 19476T= DSM 21351T).  相似文献   

17.
For the first time, morpho‐anatomical characters that were congruent with DNA sequence data were used to characterize several genera in Hapalidiaceae—the major eco‐engineers of Subarctic carbonate ecosystems. DNA sequencing of three genes (SSU, rbcL, ribulose‐1, 5‐bisphosphate carboxylase/oxygenase large subunit gene and psbA, photosystem II D1 protein gene), along with patterns of cell division, cell elongation, and calcification supported a monophyletic Clathromorphum. Two characters were diagnostic for this genus: (i) cell division, elongation, and primary calcification occurred only in intercalary meristematic cells and in a narrow vertical band (1–2 μm wide) resulting in a “meristem split” and (ii) a secondary calcification of interfilament crystals was also produced. Neopolyporolithon was resurrected for N. reclinatum, the generitype, and Clathromorphum loculosum was transferred to this genus. Like Clathromorphum, cell division, elongation, and calcification occurred only in intercalary meristematic cells, but in a wider vertical band (over 10–20 μm), and a “meristem split” was absent. Callilithophytum gen. nov. was proposed to accommodate Clathromorphum parcum, the obligate epiphyte of the northeast Pacific endemic geniculate coralline, Calliarthron. Diagnostic for this genus were epithallial cells terminating all cell filaments (no dorsi‐ventrality was present), and a distinct “foot” was embedded in the host. Leptophytum, based on its generitype, L. laeve, was shown to be a distinct genus more closely related to Clathromorphum than to Phymatolithon. All names of treated species were applied unequivocally by linking partial rbcL sequences from holotype, isotype, or epitype specimens with field‐collected material. Variation in rbcL and psbA sequences suggested that multiple species may be passing under each currently recognized species of Clathromorphum and Neopolyporolithon.  相似文献   

18.
Species discrimination within the gigartinalean red algal genus Hypnea has been controversial. To help resolve the controversy and explore phylogeny within the genus, we determined rbcL sequences from 30 specimens of 23 species within the genus, cox1 from 22 specimens of 10 species, and psaA from 16 species. We describe H. caespitosa as a new species characterized by a relatively slender main axis; a pulvinate growth habit with entangled, anastomosing, and subulate uppermost branches; and unilaterally borne tetrasporangial sori. The new species occurs in the warm waters of Malaysia, the Philippines, and Singapore. The phylogenetic trees of rbcL, psaA, and cox1 sequences showed a distant relationship of H. caespitosa to H. pannosa J. Agardh from Baja California and the marked differentiation from other similar species. The rbcL + psaA tree supported monophyly of the genus with high bootstrap values and posterior probabilities. The analysis revealed three clades within the genus, corresponding to three sections, namely, Virgatae, Spinuligerae, and Pulvinatae first recognized by J. G. Agardh. Exceptions were H. japonica T. Tanaka in Pulvinatae and H. spinella (C. Agardh) Kütz. in Spinuligerae.  相似文献   

19.
Volcanic areas with highly acidic solfatara soils and temperatures of up to 56?°C are inhabited by the red algal genus Galdieria. We examined three highly acidic but non-volcanic habitats in the western part of the Czech Republic for the occurrence of this red alga. In soil samples from the National Nature Reserve of Soos we found, together with Euglena mutabilis, Pseudococcomyxa simplex and species of Chlorella, a new strain of Galdieria. In contrast to all other Galdieria strains described so far, the strain from Soos exhibited a low temperature optimum for growth of about 30?°C. Other properties, such as the substrate spectrum for heterotrophic growth, ultrastructure, fatty acid composition, thermostability of enzymes and the nitrogen source, showed no obvious differences from other strains of Galdieria. Within a phylogenetic tree based on 18S rRNA sequence data, the strain from Soos occupied a position at the base of the ‘Galdieria’-branch. Our findings indicate that the genus Galdieria is not restricted to volcanic and mining areas and that strains of Galdieria are able to compete successfully with green algae in habitats like Soos.  相似文献   

20.
Species belonging to the newly established genus Kumanoa were sampled from locations worldwide. DNA sequence data from the rbcL gene, cox1 barcode region, and universal plastid amplicon (UPA) were collected. The new sequence data for the rbcL were combined with the extensive batrachospermalean rbcL data available in GenBank. Single gene rbcL results showed the genus Kumanoa to be a well‐supported clade, and there was high statistical support for many of the terminal nodes. However, with this gene alone, there was very little support for any of the internal nodes. Analysis of the concatenated data set (rbcL, cox1, and UPA) provided higher statistical support across the tree. The taxa K. vittata and K. amazonensis formed a basal grade, and both were on relatively long branches. Three new species are proposed, K. holtonii, K. gudjewga, and K. novaecaledonensis; K. procarpa var. americana is raised to species level. In addition, the synonymy of K. capensis and K. breviarticulata is proposed, with K. capensis having precedence. Five new combinations are made, bringing the total number of accepted species in Kumanoa to 31. The phylogenetic analyses did not reveal any interpretable biogeographic patterns within the genus (e.g., K. spermatiophora from the tropical oceanic island Maui, Hawaii, was sister to K. faroensis from temperate midcontinental Ohio in North America). Previously hypothesized relationships among groups of species were not substantiated in the phylogenetic analyses, and no intrageneric classification is recommended based on current knowledge.  相似文献   

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