Biology 4355F/G Lecture Notes - Lecture 6: Life Expectancy, Hayflick Limit, Senescence
11 Feb 2020
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What is aging: deteriorative changes occurring generally after post-reproduction phase, cellular/physiological changes that increases probability of death. Increased loss of vigor (ability to do certain physical feats and various cognitive processes: cupid, cumulative, progressive, intrinsic, deleterious. How to measure aging: demographics measures (lifespan, physiological measures (hr, muscle tone, etc, cellular measures. Population lifespan: max life span = point at which 10% of population is still alive, mean life span = age that 50% of population is still alive. Constant probability of death probability of dying not constant (more accurate) Microarray gene expression profiling: mrna from young and old mice, mrna cdna, attach fluorescent probe, hybridize to microarray, determines how many genes were unregulated and down regulated in both animals, only about 1% upregulated and 1% downregulated. Comparison of transcriptional changes during aging and with caloric restriction: caloric restriction animals live longer increase biosynthesis and macromolecule turnover, problem: study had a small sample size (looked at one tissue)
