A Podospora anserina longevity mutant with a temperature-sensitive phenotype for senescence.
A Podospora anserina longevity mutant was identified with a temperature-sensitive phenotype for senescence. This mutant, termed TS1, grew for over 3 m at 27 degrees C, but when shifted to 34 degrees C, it underwent senescence between 10 and 18 cm. A previously described senescence-associated plasmid, alpha senDNA, derived from the mitochondrial genome, was not detected in TS1 at 27 degrees C but was present in senescent cultures at 34 degrees C. A similar result was observed in progeny strains obtained by crossing the TS1 mutant with a wild-type strain. Other mitochondrial excision-amplification DNAs in addition to alpha senDNA were also observed in the senescent cultures. Most were derived from a specific region of the mitochondrial genome. These results provide evidence that alpha senDNA is involved in TS1 senescence and suggest that this plasmid may play a role in the formation of other mitochondrial excision-amplification plasmids.
Turker
M S
MS
Department of Microbiology and Immunology, University of Colorado Health Sciences Center, Denver 80262.
Nelson
J G
JG
Cummings
D J
DJ
D000375:Aging; D001203:Ascomycota / Q000235:genetics* / Q000254:growth & development; D004271:DNA, Fungal / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D005784:Gene Amplification; D005800:Genes, Fungal; D009154:Mutation; D010957:Plasmids; D013696:Temperature
D004271:DNA, Fungal; D004272:DNA, Mitochondrial