Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0983
    Keywords: Cryptomonads (Pyrenomonas salina) ; Plastid DNA ; SSUrRNA sequence ; Plastid evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cryptomonads are thought to have arisen from a symbiotic association between a eukaryotic flagellated host and a eukaryotic algal symbiont, presumably related to red algae. As organellar DNAs have proven to be useful tools in elucidating phylogenetic relationships, the plastid (pt) DNA of the cryptomonad alga Pyrenomonas salina has been characterized in some detail. A restriction map of the circular 127 kb ptDNA from Pyrenomonas salina was established. An inverted repeat (IR) region of about 5 kb separates two single-copy regions of 15 and 102 kb, respectively. It contains the genes for the small and large subunit of rRNA. Ten protein genes, coding for the large subunit of ribulose-1,5-bisphosphate carboxylase, the 47 kDa, 43 kDa and 32 kDa proteins of photosystem II, the ribosomal proteins L2, S7 and S11, the elongation factor Tu, as well as the α- and β-subunits of ATP synthase, have been localized on the restriction map either by hybridization of heterologous gene probes or by sequence homologies. The gene for the plastidal small subunit (SSUr) RNA has been sequenced and compared to homologous SSU regions from the cyanobacterium Anacystis nidulans and plastids from rhodophytes, chromophytes, euglenoids, chlorophytes, and land plants. A phylogenetic tree constructed with the neighborliness method and indicating a relationship of cryptomonad plastids with those of red algae is presented.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Summary The penetration of plant tissues (spruce needles and storage parenchyma of potatoes) by solutions of different concentration of OsO4, formaldehyde and KMnO4 was investigated with the following results: 1. The velocity of penetration increases with the concentration of the fixative, but the dependence is not linear. 2. The moist tissues are, in general, more quickly penetrated than the dryer. 3. The velocity of penetration is only insignificantly affected by the addition of non-fixatives (buffer, glucose, urea) to the OsO4-solutions. 4. At 4° C the penetration (of spruce needles) of the OsO4-solution is scarcely slower than at room temperature. At 40° C it is perceptably slower. 5. The penetration of the fixative is not a simple diffusion. The diffusion „constant“ of the tissue is reduced by the fixative. 6. When the molar concentrations are the same, OsO4 penetrates the fastest, KMnO4 somewhat slower and formaldehyde slower yet.
    Notes: Zusammenfassung Untersucht wurde unter verschiedenen Bedingungen das Eindringen verschieden konzentrierter Lösungen von OsO4, Formaldehyd und KMnO4 in Pflanzengewebe (Nadeln der Fichte, Speicherparenchym der Kartoffelknolle). Folgende Ergebnisse wurden erhalten: 1. Das Eindringen erfolgt um so rascher, je höher die Konzentration des Fixans ist; zwischen Eindringgeschwindigkeit und Konzentration besteht jedoch kein linearer Zusammenhang. 2. Im allgemeinen werden wasserreiche Gewebe rascher durchdrungen als wasserarme. 3. Nicht-fixierende Zusätze zu OsO4-Lösungen (Puffer, Glucose, Harnstoff) beeinflussen die Eindringgeschwindigkeit nur unbedeutend. 4. OsO4-Lösungen dringen in Fichtennadeln bei 4° C kaum langsamer ein als bei Zimmertemperatur; bei 40° ist das Eindringen verlangsamt. 5. Das Eindringen der Fixantien ist keine einfache Diffusion. Die Diffusions-„Konstante“ des Gewebes wird durch die Fixierung verringert. 6. Bei gleicher molarer Konzentration dringt OsO4 am schnellsten ein, MnO4 etwas langsamer, Formol am langsamsten.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 56 (1963), S. 197-201 
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Osmiophilic globuli in the chloroplasts of the leaves ofAtrichum undulatum (a moss) are found to be arranged in striking hexagonal patterns. It seems to be most likely that there are systems which arrange themselves producing by this means these remarcable patterns.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 49 (1958), S. 447-522 
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-1432
    Keywords: Algal phylogeny ; Chloroplast evolution ; Cryptomonads ; Pyrenomonas salina ; Small subunit rRNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The cryptomonadPyrenomonas salina presumably has arisen from a symbiotic event involving a flagellated phagotrophic host cell and a photosynthetic eukaryote as the symbiont. Correspondingly, in this unicellular alga there are four different genomes, e.g., the nuclear and the mitochondrial genomes of the host cell as well as the plastid genome and the genome contained in the vestigial nucleus of the endocytobiont (nucleomorph). To analyze the orgin of one of the symbiotic partners the small subunit rRNA gene sequence of the host cell nucleus was determined, and a secondary structure model has been constructed. This sequence is compared to those of 40 other eukaryotes. A phylogenetic tree constructed using the neighborliness method revealed a close relationship between the host cell ofP. salina and the chlorophytes, whereas the rhodophytes diverge more deeply in the tree.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-203X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plastoglobules have been isolated in pure form from petals of the pansy, Viola tricolor L. Their chemical composition has been determined up to a recovery of 96% dry weight. Triacyl glycerols (57%) as well as carotenoids and their esters (23%) are the main constituents. Polar lipids, proteins, alkanes, phytyl esters, plastid quinones, and steryl esters have been detected in smaller amounts (cf. Table 1). The mean diameter of chromoplast globules is 280±70 nm (corresponding to a volume of 11.7×106 nm3), their buoyant density 0.93 g cm−3. The plastoglobules are devoid of a surrounding unit membrane. However, electron microscopical evidence and analytical data are consistent with a structural model envisaging the globules to consist mainly of an apolar core, covered by a ‘half unit membrane’ of polar constituents.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-5028
    Keywords: cryptomonads ; gene map ; mtDNA ; mitochondrial evolution ; Pyrenomonas salina ; restriction map
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mitochondrial DNA (mtDNA) from the cryptomonad Pyrenomonas salina was isolated by CsCl-buoyant density centrifugation of whole-cell DNA in the presence of Hoechst dye 33258. mtDNA consists of circular molecules about 47 kb in size as estimated from restriction enzyme analysis. A physical map for six restriction enzymes (Bam HI, Bge I, Eco RI, Pst I, Sac I and Sac I) has been constructed. Genes coding for the small subunit of rRNA, cytochrome oxidase subunits I and II, and apocytochrome b were localized on this map using Southern blot hybridization with heterologous gene probes from Oenothera. Genes for 5S rRNA and NADH dehydrogenase subunit 5 are absent from P. salina mtDNA. The mitochondrial genome, being the first analysed to this extent in chromophytic algae, should be valuable for taxonomic and phylogenetic studies.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Biologie in unserer Zeit 12 (1982), S. 64-64 
    ISSN: 0045-205X
    Keywords: Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Biologie in unserer Zeit 19 (1989), S. 141-142 
    ISSN: 0045-205X
    Keywords: Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0045-205X
    Keywords: Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...