title: A DNA polymerase activity with characteristics of a reverse transcriptase in Podospora anserina.
abstract: In the filamentous ascomycete fungus Podospora anserina, senescence is associated with dramatic changes of the juvenile mitochondrial genome. During senescence specific regions of the non-senescent genome are excised, ligated and amplified as a plasmid. In this paper, we report our studies on nuclear-mitochondrial extracts for the presence of RNA-dependent DNA polymerase activity (reverse transcriptase). In so-called middle aged mycelia of race A, we detected a DNA polymerase possessing properties of a reverse transcriptase. It prefers the ribopolymer templates poly(rA)-oligo(dT)12-18 and poly(rCm)-oligo(dG)12-18 over the deoxypolymer template poly(dA)-oligo(dT)12-18. It also uses natural rabbit globin mRNA as a template. The enzymatic activity can clearly be distinguished from a second DNA polymerase activity found in the same extracts of both young and middle aged mycelia.
mesh_terms: D000375:Aging; D001203:Ascomycota / Q000201:enzymology*; D002467:Cell Nucleus / Q000201:enzymology; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism*
chemical_list: D012194:RNA-Directed DNA Polymerase; D004259:DNA-Directed DNA Polymerase