Nucleotide Sequence Homology Exists between the Chloroplast and Nuclear Ribosomal DNAs of <i>Euglena gracilis</i>

Curtis, S. E.; Rawson, James R.Y.

doi:10.1104/pp.69.1.67

Cited by 10 publications

(1 citation statement)

References 12 publications

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“…In addition, a 2,300 nucleotide RNA hybridizes faintly with the probe from the 16S rRNA gene. This results most likely from hybridization to the cytoplasmic small subunit rRNA, which is 2,305 nucleotides in length (Sogin et al 1986) and has been shown to hybridize with the chloroplast 16S gene on Southern blots (Curtis and Rawson 1982). The 2,300 nucleotide band was not seen in Northern blots of RNA from isolated chloroplasts (McGarvey 1988).…”

Section: Analysis Of Rrn Transcription Using Northern Blot Hybridizationmentioning

confidence: 96%

Processing of chloroplast ribosomal RNA transcripts in Euglena gracilis bacillaris

McGarvey

Helling

1989

Curr Genet

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The ribosomal RNA operons (rrn operons) of Euglena gracilis chloroplasts contain genes for (in order) 16S rRNA, tRNA(Ile), tRNA(Ala),23S rRNA and 5S rRNA. Major sites of cleavage of the primary rrn transcript were identified by Northern blot hybridization and S1-mapping. The presumptive termini of all of the mature products have now been identified. During initial processing in the chloroplast, the primary transcript is cleaved between the two tRNAs and between the 23S and 5S rRNAs so as to separate the sequences found in the different mature rRNAs. Subsequently the tRNAs are separated from the rRNAs, further trimming provides the remaining proper ends, and the 3'-ends of the tRNAs are added.

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Section: Analysis Of Rrn Transcription Using Northern Blot Hybridizationmentioning

confidence: 96%

Processing of chloroplast ribosomal RNA transcripts in Euglena gracilis bacillaris

McGarvey

Helling

1989

Curr Genet

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Homologies between nuclear and plastid DNA in spinach

1984

Theoret Appl Genet

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Homologies between spinach nuclear (n) DNA and Chloroplast (pt) DNA, have been detected with a clone bank of spinach ptDNA as hybridization probes to restriction fragments of nDNA prepared from purified root nuclei. Every cloned fragment of ptDNA showed homologies to discrete restriction fragments of nDNA, different from those of ptDNA, indicating integration of these homologies into nDNA. While most ptDNA clones were relatively large and probably contained several genes, sequence homologies were also found to the cloned plastid gene for RuBP carboxylase and the β subunit of ptATPase. Many of the homologies in nDNA occur in regions of the genome that are highly methylated and are not digested by the methylation sensitive restriction endonucleases HpaII and MspI. In contrast these enzymes cleave ptDNA into small fragments which allows the nDNA homologies to be distinguished in total root DNA. The sequence homologies observed were not due to contaminating non nuclear sequences as shown by hybridization to mitochondrial (mt) and bacterial DNAs. The total amount of homology to ptDNA in nDNA is equivalent to about five copies of the plastome per haploid nuclear genome. The homologies generally appear to be in individual segments of less than 2 kbp in length, integrated into several different places in the genome.

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Potassium channels in Eremosphaera viridis

Köhler

Steigner

Simonis

et al. 1985

Planta

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The dependence of the membrane potential of Eremosphaera viridis on different external concentrations of potassium, sodium, calcium, and protons was compared with the diffusion potential measured in the dark and in the presence of NaN3. In contrast to some other algae, the membrane potential in the light as well as in the dark seemed to be predominantly determined by the calculated diffusion potential and less by an electrogenic pump which, however, seemed to be involved at potassium concentrations >1 mol·m(-3) and at higher pHos (>pH 6). Furthermore, some characteristics of an action-potential-like response (CAP) triggered by light-off, and independent of the membrane-potential threshold value, were determined. The CAP had a delay period of 5.4 s and needed 4.5 s for polarization to a plateau. On average, the plateau held for 8.8 s and the CAP lasted 37.7 s. The peak amplitudes of CAP (P AP) exactly followed the Nernst potential of potassium. Other cations like sodium, calcium and protons did not appreciably affect the peak amplitudes of CAP. From these and other results it can be assumed that the CAP is caused by a temporary opening of potassium channels in the plasma membrane of Eremosphaera (Köhler et al., 1983, Planta 159, 165-171). The release of a CAP by light-off has been partly explained by the participation of a transient increase of proton concentration in the cytoplasm. It was possible to trigger a CAP by external pH changes and by the addition of sodium acetate, thus supporting the hypothesis that a pH decrease in the cytoplasm may be one element of the signal transfer from the photosynthetic system to the potassium channels in the plasmalemma. Calcium also seemed to have an influence on triggering the CAP.

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Nucleotide Sequence Homology Exists between the Chloroplast and Nuclear Ribosomal DNAs of Euglena gracilis

Cited by 10 publications

References 12 publications

Processing of chloroplast ribosomal RNA transcripts in Euglena gracilis bacillaris

Processing of chloroplast ribosomal RNA transcripts in Euglena gracilis bacillaris

Homologies between nuclear and plastid DNA in spinach

Potassium channels in Eremosphaera viridis

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