Holmes G E, Holmes N R
Gerontology. 1986;32(5):252-60. doi: 10.1159/000212799.
The accumulation of DNA fragments in aging Paramecium tetraurelia after 15 days (or approximately 60 generations) of clonal growth in both axenic and nonaxenic media was assayed by alkaline elution assay. This sensitive technique permits measurement of single-strand breaks in double-stranded DNA. The results obtained indicate that P. tetraurelia aged in axenic medium accumulate more apurinic/apyrimidinic lesions, strand breaks, or single-strand gaps than do P. tetraurelia aged in nonaxenic medium. This implies that cells grown in axenic medium have a shorter lifespan than do cells grown in nonaxenic medium. The accumulation of DNA fragments may be the basic mechanism of aging in P. tetraurelia.
通过碱性洗脱分析，检测了在无菌和非无菌培养基中克隆生长15天（或约60代）后，衰老的四膜虫中DNA片段的积累情况。这种灵敏的技术能够测量双链DNA中的单链断裂。所得结果表明，在无菌培养基中衰老的四膜虫比在非无菌培养基中衰老的四膜虫积累了更多的无嘌呤/无嘧啶损伤、链断裂或单链缺口。这意味着在无菌培养基中生长的细胞比在非无菌培养基中生长的细胞寿命更短。DNA片段的积累可能是四膜虫衰老的基本机制。
