ISSN:
1432-0983
Keywords:
Podospora anserina
;
Group II intron
;
Lariat RNA
;
Senescence
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary In senescing strains of the filamentous ascomycete Podospora anserina, the first intron (il) of the mitochondrial gene for cytochrome-c-oxidase subunit I (CO I), a group II intron, accumulates as a circular mitochondrial plasmid (plDNA). In both juvenile and senescent wild type strain s two highly abundant transcripts were detected homologous to il and plDNA. In this report we show that these RNAs are identical molecules having different conformations: the first is a lariat, the second a corresponding linear molecule probably resulting from breakage of the branched circular form. Our findings suggest that the transcripts arise from processing of CO I pre-mRNA, including il, rather than from transcription of the excised plasmid. The significance of the lariat RNA concerning plDNA amplification via a postulated reverse transcription mechanism is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00435292
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