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Sample records for acetabularia

  1. Radiobiological and radioecological studies with the unicellular marine algae Acetabularia, Batophora and Dunaliella

    Radiobiological studies of the biological and chemical effects of X-rays on the marine algae Acetabularia and Batophora and the incorporation of 3H in Acetabularia and Dunaliello were performed. It was shown that the main morphogenetic process of Acetabularia and Batophora are affected by the radiations. Experiments with tritiated water revealed that Acetabularia cells are unable to concentrate 3H. However, a significant amount of this radionuclide is incorporated into the genetic material of the cells. When organically bound 3H is supplied to Acetabularia or Dunaliello, a selective accumulation of some substances is observed. (H.K.)

  2. Morphology of the nucleo-cytoplasmic interactions during the development of Acetabularia cells. I. The vegetative phase

    Franke, Werner W.; Berger, S.; Falk, Heinz; Spring, H.; Scheer, Ulrich; Trendelenburg, Michael F.; Schweiger, H G; Herth, W

    2009-01-01

    The ultrastructure of th e growin g and ma turing primary nucleus of Acetabularia medite rranea and Acetabularia major has been studied with the use of various fi xation procedures. Particular interest has been focused on the deta ils of the nuclear periphery and the perinuclear region. It is demonstrated that early in nuclear grow th a characteristic perinucl ear structura l complex is formed which is, among the eukaryotic cells, unique to Acetabularia and re lated genera. This perinuclear s...

  3. Comparison of ESTs from juvenile and adult phases of the giant unicellular green alga Acetabularia acetabulum

    Grotewold Erich

    2004-03-01

    Full Text Available Abstract Background Acetabularia acetabulum is a giant unicellular green alga whose size and complex life cycle make it an attractive model for understanding morphogenesis and subcellular compartmentalization. The life cycle of this marine unicell is composed of several developmental phases. Juvenile and adult phases are temporally sequential but physiologically and morphologically distinct. To identify genes specific to juvenile and adult phases, we created two subtracted cDNA libraries, one adult-specific and one juvenile-specific, and analyzed 941 randomly chosen ESTs from them. Results Clustering analysis suggests virtually no overlap between the two libraries. Preliminary expression data also suggests that we were successful at isolating transcripts differentially expressed between the two developmental phases and that many transcripts are specific to one phase or the other. Comparison of our EST sequences against publicly available sequence databases indicates that ESTs from the adult and the juvenile libraries partition into different functional classes. Three conserved sequence elements were common to several of the ESTs and were also found within the genomic sequence of the carbonic anhydrase1 gene from A. acetabulum. To date, these conserved elements are specific to A. acetabulum. Conclusions Our data provide strong evidence that adult and juvenile phases in A. acetabulum vary significantly in gene expression. We discuss their possible roles in cell growth and morphogenesis as well as in phase change. We also discuss the potential role of the conserved elements found within the EST sequences in post-transcriptional regulation, particularly mRNA localization and/or stability.

  4. UniProt search blastx result: AK288054 [KOME

    Full Text Available AK288054 J075152E14 P16134|RBS1_ACEAT Ribulose bisphosphate carboxylase small chain 1, chloropla ... ll subunit 1) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  5. UniProt search blastx result: AK288054 [KOME

    Full Text Available AK288054 J075152E14 P16137|RBS4_ACEAT Ribulose bisphosphate carboxylase small chain 4, chloropla ... ll subunit 4) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 3.00E-31 ...

  6. UniProt search blastx result: AK287599 [KOME

    Full Text Available AK287599 J065050G24 P16138|RBS5_ACEAT Ribulose bisphosphate carboxylase small chain 5, chloropla ... ll subunit 5) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 6.00E-32 ...

  7. UniProt search blastx result: AK288517 [KOME

    Full Text Available AK288517 J090043B03 P16137|RBS4_ACEAT Ribulose bisphosphate carboxylase small chain 4, chloropla ... ll subunit 4) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 9.00E-31 ...

  8. UniProt search blastx result: AK288054 [KOME

    Full Text Available AK288054 J075152E14 P16138|RBS5_ACEAT Ribulose bisphosphate carboxylase small chain 5, chloropla ... ll subunit 5) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 4.00E-32 ...

  9. UniProt search blastx result: AK288517 [KOME

    Full Text Available AK288517 J090043B03 P16136|RBS3_ACEAT Ribulose bisphosphate carboxylase small chain 3, chloropla ... ll subunit 3) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  10. UniProt search blastx result: AK288517 [KOME

    Full Text Available AK288517 J090043B03 P16138|RBS5_ACEAT Ribulose bisphosphate carboxylase small chain 5, chloropla ... ll subunit 5) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 7.00E-31 ...

  11. UniProt search blastx result: AK288517 [KOME

    Full Text Available AK288517 J090043B03 P16134|RBS1_ACEAT Ribulose bisphosphate carboxylase small chain 1, chloropla ... ll subunit 1) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  12. UniProt search blastx result: AK288517 [KOME

    Full Text Available AK288517 J090043B03 P16135|RBS2_ACEAT Ribulose bisphosphate carboxylase small chain 2, chloropla ... 2) (Fragment) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  13. UniProt search blastx result: AK287599 [KOME

    Full Text Available AK287599 J065050G24 P16137|RBS4_ACEAT Ribulose bisphosphate carboxylase small chain 4, chloropla ... ll subunit 4) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 5.00E-31 ...

  14. UniProt search blastx result: AK288054 [KOME

    Full Text Available AK288054 J075152E14 P16136|RBS3_ACEAT Ribulose bisphosphate carboxylase small chain 3, chloropla ... ll subunit 3) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 8.00E-32 ...

  15. UniProt search blastx result: AK287599 [KOME

    Full Text Available AK287599 J065050G24 P16134|RBS1_ACEAT Ribulose bisphosphate carboxylase small chain 1, chloropla ... ll subunit 1) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  16. UniProt search blastx result: AK287599 [KOME

    Full Text Available AK287599 J065050G24 P16136|RBS3_ACEAT Ribulose bisphosphate carboxylase small chain 3, chloropla ... ll subunit 3) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  17. UniProt search blastx result: AK288054 [KOME

    Full Text Available AK288054 J075152E14 P16135|RBS2_ACEAT Ribulose bisphosphate carboxylase small chain 2, chloropla ... 2) (Fragment) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  18. UniProt search blastx result: AK287599 [KOME

    Full Text Available AK287599 J065050G24 P16135|RBS2_ACEAT Ribulose bisphosphate carboxylase small chain 2, chloropla ... 2) (Fragment) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  19. Reference: PROLAMINBOX [PLACE

    Full Text Available PROLAMINBOX Brown JWS, Wandelt C, Feix G The upstream regions of zein genes: sequence analysis a ... nd expression in the unicellular green ... alga Acetabularia. Eur J Cell Biol 42:161-170 (198 ...

  20. Light-triggered action potentials in plants

    Kazimierz Trębacz

    2014-01-01

    Special attention is paid in this paper to the criteria of the light-triggered action potential, namely the all-or-none law, propagation, the occurrence of refractory periods. Such action potentials have been recorded in Acetabularia mediterranea, Asplenium trichomanes, Bryum pseudotriquetrum, Eremosphaera viridis and Concephalum conicum. In Acetabularia, action potentials are generated after sudden cessation of light stimuli of sufficient intensity. The depolarization phase of the action pot...

  1. Recent changes in macroalgae distribution patterns in the Orbetello lagoon (Italy)

    Giovani, Andrea; Mari, Elena; Specchiulli, Antonietta; Focardi, Silvano; RENZI, Monia

    2014-01-01

    This study related recent distribution changes in seven macroalgae taxa (Acetabularia acetabulum, Chaetomorpha linum, Cladophora sp., Gracilariopsis longissima, Spyridia sp., Ulva laetevirens, Valonia aegagrophyla) to spatial (basin) and temporal (time) trophic differences in a meso-eutrophic Mediterranean coastal lagoon (Orbetello, Italy). In July 2003 and July 2009, the coverage percentage (CP) of each considered taxon was measured in 38 stations equally distributed in the Western and Easte...

  2. Cell probing by delayed luminescence

    Musumeci, Francesco; Ballerini, Monica; Baroni, Giuliana; Costato, Michele; Ferraro, Lorenzo; Milani, Marziale; Scordino, Agata; Triglia, Antonio

    1999-05-01

    Delayed luminescence (D.L.) is a measure that provides important information on biological systems fields, structures and activities, by counting impinging and emitted photons. Many recent experimental works have shown the existence of a close connection, sometimes analytically expressed between the biological state of the system and D.L. parameters. Our investigations aim to show that D.L. is a workable analytical technique covering a large number of disciplinary fields, from agriculture to pollution control and from medical diagnostics to food quality control. The authors have conducted systematic research about D.L. from unicellular alga Acetabularia acetabulum to Saccharomyces cerevisiae yeast cultures and about more complex systems such as Soya seed (Glycine max, L.) and its dependence on sample preparation, history, intracellular signaling, metabolism and pollutant presence. We will discuss the most relevant results together with theoretical considerations on the basic interaction at work between biological systems and electromagnetic fields.

  3. Clorofíceas marinhas bentônicas da Praia de Serrambi, Pernambuco, Brasil Benthic marine Chlorophyceae from Serrambi Beach, Pernambuco, Brazil

    Sônia Maria Barreto Pereira

    1998-04-01

    Full Text Available É apresentado o levantamento florístico sobre as clorofíceas marinhas bentônicas encontradas na Praia de Serrambi, litoral Sul do Estado de Pernambuco. O material estudado foi coletado em três estações, as quais foram visitadas mensalmente durante o período de abril de 1986 a setembro de 1987. As clorofíceas foram representadas na flora local por 39 espécies, três variedades e uma forma, pertencentes às ordens Ulotrichales, Ulvales, Siphonocladales, Cladophorales, Caulerpales e Dasycladales. Acetabularia calyculus Quoy & Gaimard. In Freycinet, Bryopsis pennata Lamouroux, Bryopsis plumosa (Hudson C. Agardh, Caulerpa ambigua Okamura, Caulerpa serrulata (Forsskål J. Agardh emend Børgesen, Chaetomorpha brachygona Harvey, Cladophora coelothrix Kützing, Cladophoropsis membranacea (C. Agardh Børgesen, Codium intertextum Collins & Hervey, Ernodesmis verticillata (Kützing Børgesen são novas referências para a flora do litoral de Pernambuco. Pringsheimiella scutata (Reinke von Höhnel ex Marchewianka o é também para o litoral continental do Brasil. Halimeda opuntia (L. Lamouroux foi hospedeira de maior número de epífitas, enquanto Bryopsis plumosa, quando epífita, foi a que cresceu sobre maior número de hospedeiros.This survey presents studies about benthics marine chlorophyceae found in the Serrambi Beach, South coast of Pernambuco. The material studied was collected in three stations, which were visited monthly during the period from April, 1986 to September, 1987. The chlorophyceae were represented in this flora by 39 species, three varieties and one form, from orders Ulotrichales, Ulvales, Siphonocladales, Cladophorales, Caulerpales and Dasycladales. Acetabularia calyculus Quoy & Gaimard. In Freycinet, Bryopsis pennata Lamouroux, Bryopsis plumosa (Hudson C. Agardh, Caulerpa ambigua Okamura, Caulerpa serrulata (Forsskål J. Agardh emend Børgesen, Chaetomorpha brachygona Harvey, Cladophora coelothrix Kützing, Cladophoropsis

  4. Cllmodulin in tip-growing plant cells, visualized by fluorescing calmodulin-binding phenothiazines.

    Haußer, I; Herth, W; Reiss, H D

    1984-09-01

    Calmodulin (CaM) was visualized light-microscopically by the fluorescent CaM inhibitors fluphenazine and chlorpromazine, both phenothiazines, during polar tip growth of pollen tubes of Lilium longiflorum, root hairs of Lepidium sativum, moss caulonema of Funaria hygrometrica, fungal hyphae of Achlya spec. and in the alga Acetabularia mediterranea, as well as during multipolar tip growth in Micrasterias denticulata. Young pollen tubes and root hairs showed tip fluorescence; at later stages and in the growing parts of the other subjects the fluorescence was almost uniform. After treatment with cytochalasin B, punctuate fluorescence occurred in the clear zone adjacent to the tip of pollen tubes. The observations indicate that there is CaM in all our tested systems detectable with this method. It may play a key role in starting polar growth. As in pollen tubes, CaM might be in part associated with the microfilament network at the tip, and thus regulate vesicle transport and cytoplasmic streaming. PMID:24253945

  5. Tracing the evolution of the light-harvesting antennae in chlorophyll a/b-containing organisms.

    Koziol, Adam G; Borza, Tudor; Ishida, Ken-Ichiro; Keeling, Patrick; Lee, Robert W; Durnford, Dion G

    2007-04-01

    The light-harvesting complexes (LHCs) of land plants and green algae have essential roles in light capture and photoprotection. Though the functional diversity of the individual LHC proteins are well described in many land plants, the extent of this family in the majority of green algal groups is unknown. To examine the evolution of the chlorophyll a/b antennae system and to infer its ancestral state, we initiated several expressed sequence tag projects from a taxonomically broad range of chlorophyll a/b-containing protists. This included representatives from the Ulvophyceae (Acetabularia acetabulum), the Mesostigmatophyceae (Mesostigma viride), and the Prasinophyceae (Micromonas sp.), as well as one representative from each of the Euglenozoa (Euglena gracilis) and Chlorarachniophyta (Bigelowiella natans), whose plastids evolved secondarily from a green alga. It is clear that the core antenna system was well developed prior to green algal diversification and likely consisted of the CP29 (Lhcb4) and CP26 (Lhcb5) proteins associated with photosystem II plus a photosystem I antenna composed of proteins encoded by at least Lhca3 and two green algal-specific proteins encoded by the Lhca2 and 9 genes. In organisms containing secondary plastids, we found no evidence for orthologs to the plant/algal antennae with the exception of CP29. We also identified PsbS homologs in the Ulvophyceae and the Prasinophyceae, indicating that this distinctive protein appeared prior to green algal diversification. This analysis provides a snapshot of the antenna systems in diverse green algae, and allows us to infer the changing complexity of the antenna system during green algal evolution. PMID:17307901

  6. Recent evidence for evolution of the genetic code

    Osawa, S.; Jukes, T. H.; Watanabe, K.; Muto, A.

    1992-01-01

    The genetic code, formerly thought to be frozen, is now known to be in a state of evolution. This was first shown in 1979 by Barrell et al. (G. Barrell, A. T. Bankier, and J. Drouin, Nature [London] 282:189-194, 1979), who found that the universal codons AUA (isoleucine) and UGA (stop) coded for methionine and tryptophan, respectively, in human mitochondria. Subsequent studies have shown that UGA codes for tryptophan in Mycoplasma spp. and in all nonplant mitochondria that have been examined. Universal stop codons UAA and UAG code for glutamine in ciliated protozoa (except Euplotes octacarinatus) and in a green alga, Acetabularia. E. octacarinatus uses UAA for stop and UGA for cysteine. Candida species, which are yeasts, use CUG (leucine) for serine. Other departures from the universal code, all in nonplant mitochondria, are CUN (leucine) for threonine (in yeasts), AAA (lysine) for asparagine (in platyhelminths and echinoderms), UAA (stop) for tyrosine (in planaria), and AGR (arginine) for serine (in several animal orders) and for stop (in vertebrates). We propose that the changes are typically preceded by loss of a codon from all coding sequences in an organism or organelle, often as a result of directional mutation pressure, accompanied by loss of the tRNA that translates the codon. The codon reappears later by conversion of another codon and emergence of a tRNA that translates the reappeared codon with a different assignment. Changes in release factors also contribute to these revised assignments. We also discuss the use of UGA (stop) as a selenocysteine codon and the early history of the code.

  7. What remains after 2 months of starvation? Analysis of sequestered algae in a photosynthetic slug, Plakobranchus ocellatus (Sacoglossa, Opisthobranchia), by barcoding.

    Christa, Gregor; Wescott, Lily; Schäberle, Till F; König, Gabriele M; Wägele, Heike

    2013-02-01

    The sacoglossan sea slug, Plakobranchus ocellatus, is a so-called long-term retention form that incorporates chloroplasts for several months and thus is able to starve while maintaining photosynthetic activity. Little is known regarding the taxonomy and food sources of this sacoglossan, but it is suggested that P. ocellatus is a species complex and feeds on a broad variety of Ulvophyceae. In particular, we analysed specimens from the Philippines and starved them under various light conditions (high light, low light and darkness) and identified the species of algal food sources depending on starvation time and light treatment by means of DNA-barcoding using for the first time the combination of two algal chloroplast markers, rbcL and tufA. Comparison of available CO1 and 16S sequences of specimens from various localities indicate a species complex with likely four distinct clades, but food analyses do not indicate an ecological separation of the investigated clades into differing foraging strategies. The combined results from both algal markers suggest that, in general, P. ocellatus has a broad food spectrum, including members of the genera Halimeda, Caulerpa, Udotea, Acetabularia and further unidentified algae, with an emphasis on H. macroloba. Independent of the duration of starvation and light exposure, this algal species and a further unidentified Halimeda species seem to be the main food source of P. ocellatus from the Philippines. It is shown here that at least two (or possibly three) barcode markers are required to cover the entire food spectrum in future analyses of Sacoglossa. PMID:23108662

  8. Gain and loss of polyadenylation signals during evolution of green algae

    Glöckner Gernot

    2007-04-01

    Full Text Available Abstract Background The Viridiplantae (green algae and land plants consist of two monophyletic lineages: the Chlorophyta and the Streptophyta. Most green algae belong to the Chlorophyta, while the Streptophyta include all land plants and a small group of freshwater algae known as Charophyceae. Eukaryotes attach a poly-A tail to the 3' ends of most nuclear-encoded mRNAs. In embryophytes, animals and fungi, the signal for polyadenylation contains an A-rich sequence (often AAUAAA or related sequence 13 to 30 nucleotides upstream from the cleavage site, which is commonly referred to as the near upstream element (NUE. However, it has been reported that the pentanucleotide UGUAA is used as polyadenylation signal for some genes in volvocalean algae. Results We set out to investigate polyadenylation signal differences between streptophytes and chlorophytes that may have emerged shortly after the evolutionary split between Streptophyta and Chlorophyta. We therefore analyzed expressed genes (ESTs from three streptophyte algae, Mesostigma viride, Klebsormidium subtile and Coleochaete scutata, and from two early-branching chlorophytes, Pyramimonas parkeae and Scherffelia dubia. In addition, to extend the database, our analyses included ESTs from six other chlorophytes (Acetabularia acetabulum, Chlamydomonas reinhardtii, Helicosporidium sp. ex Simulium jonesii, Prototheca wickerhamii, Scenedesmus obliquus and Ulva linza and one streptophyte (Closterium peracerosum. Our results indicate that polyadenylation signals in green algae vary widely. The UGUAA motif is confined to late-branching Chlorophyta. Most streptophyte algae do not have an A-rich sequence motif like that in embryophytes, animals and fungi. We observed polyadenylation signals similar to those of Arabidopsis and other land plants only in Mesostigma. Conclusion Polyadenylation signals in green algae show considerable variation. A new NUE (UGUAA was invented in derived chlorophytes and replaced