We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
A sequence of mitochondrial DNA is associated with the onset of senescence in a fungus.
- Authors
Vierny, Corinne; Keller, Anne-Marie; Begel, Odile; Belcour, Léon
- Abstract
In Podospora anserina, a strict aerobic fungus, senescence1 (arrest of vegetative growth of the mycelium) is correlated with severe modifications of the mitochondrial DNA similar to those observed in the rho− mutants of yeast2. Senescent cultures yield a specific DNA (SEN-DNA) consisting of small circular molecules arranged in multimeric series of sizes3,4 and which results from the amplification of either one of two non-overlapping segments of the mitochondrial DNA5,6. One region 0.89 µm long [2.6 kilobases (kb)] is most frequently amplified, in different strains of P. anserina and also in subcultures of a strain reaching senescence independently6. In 'young' cultures of the mating type-minus wild-type strain s (s mt−), the 2.6 kb region exists both as an integral part of the mitochondrial chromosome and as rare free sequences6. The results presented here show that (1) the free form is absent from two strains, s mt+ and s mt− capr1, which both display increased longevity and which differ respectively from the s mt− strain by a nuclear allele at the mt locus and by a mitochondrial mutation conferring resistance to chloramphenicol; and (2) in the mutant mex1, which develops beyond the edge of arrest of a senescent mycelium, that is, escapes senescence, the mitochondrial DNA precisely lacks the 2.6kb region. The results suggest that excision and/or amplification of the 2.6 kb sequence is the cause of senescence.
- Publication
Nature, 1982, Vol 297, Issue 5862, p157
- ISSN
0028-0836
- Publication type
Article
- DOI
10.1038/297157a0