TY - JOUR
T1 - Extended Twilight among Isogenic C. elegans Causes a Disproportionate Scaling between Lifespan and Health
AU - Zhang, William B.
AU - Sinha, Drew B.
AU - Pittman, William E.
AU - Hvatum, Erik
AU - Stroustrup, Nicholas
AU - Pincus, Zachary
N1 - Publisher Copyright:
© 2016 Elsevier Inc.
PY - 2016/10/26
Y1 - 2016/10/26
N2 - Although many genetic factors and lifestyle interventions are known to affect the mean lifespan of animal populations, the physiological variation displayed by individuals across their lifespans remains largely uncharacterized. Here, we use a custom culture apparatus to continuously monitor five aspects of aging physiology across hundreds of isolated Caenorhabditis elegans individuals kept in a constant environment from hatching until death. Aggregating these measurements into an overall estimate of senescence, we find two chief differences between longer- and shorter-lived individuals. First, though long- and short-lived individuals are physiologically equivalent in early adulthood, longer-lived individuals experience a lower rate of physiological decline throughout life. Second, and counter-intuitively, long-lived individuals have a disproportionately extended “twilight” period of low physiological function. While longer-lived individuals experience more overall days of good health, their proportion of good to bad health, and thus their average quality of life, is systematically lower than that of shorter-lived individuals. We conclude that, within a homogeneous population reared under constant conditions, the period of early-life good health is comparatively uniform, and the most plastic period in the aging process is end-of-life senescence.
AB - Although many genetic factors and lifestyle interventions are known to affect the mean lifespan of animal populations, the physiological variation displayed by individuals across their lifespans remains largely uncharacterized. Here, we use a custom culture apparatus to continuously monitor five aspects of aging physiology across hundreds of isolated Caenorhabditis elegans individuals kept in a constant environment from hatching until death. Aggregating these measurements into an overall estimate of senescence, we find two chief differences between longer- and shorter-lived individuals. First, though long- and short-lived individuals are physiologically equivalent in early adulthood, longer-lived individuals experience a lower rate of physiological decline throughout life. Second, and counter-intuitively, long-lived individuals have a disproportionately extended “twilight” period of low physiological function. While longer-lived individuals experience more overall days of good health, their proportion of good to bad health, and thus their average quality of life, is systematically lower than that of shorter-lived individuals. We conclude that, within a homogeneous population reared under constant conditions, the period of early-life good health is comparatively uniform, and the most plastic period in the aging process is end-of-life senescence.
KW - Caenorhabditis elegans
KW - health
KW - healthspan
KW - inter-individual variation
KW - lifespan
KW - rate of aging
UR - http://www.scopus.com/inward/record.url?scp=84992080184&partnerID=8YFLogxK
U2 - 10.1016/j.cels.2016.09.003
DO - 10.1016/j.cels.2016.09.003
M3 - Article
C2 - 27720632
AN - SCOPUS:84992080184
SN - 2405-4712
VL - 3
SP - 333-345.e4
JO - Cell Systems
JF - Cell Systems
IS - 4
ER -