Data Mining the Mechanisms of Aging in Nematodes

In this day and age, the big advantage provided by conducting studies of aging in short-lived, small species such as nematodes is that it is cost-effective to build increasingly sophisticated processes of automation for such research. Gathering very detailed data on large numbers of individuals becomes possible, and this allows for greater introspection into the mechanisms of aging through statistical methods. The results here are quite interesting, for example, and could not be obtained from mammals given current budgets and constraints on technology:

In order to study life span dynamics at the population level, researchers constructed the Lifespan Machine, a device comprising 50 off-the-shelf flatbed scanners purchased from an office supplies store. Each scanner has been retooled to record 16 petri dishes every hour, totaling 800 dishes and 30,000 nematode worms. The scanners capture images at 3,200 dots per inch, which is a resolution high enough to detect movements of eight micrometers, or about 12 percent of the width of an average worm. The researchers subjected the worms to interventions as diverse as temperature changes, oxidative stress, changes in diet and genetic manipulations that altered, for example, insulin growth factor signaling. The Lifespan Machine recorded how long it took the worms to die under each condition. The researchers then aggregated the data, generated life span distribution curves for each intervention and compared results.

The life span distributions provided considerably more information than just changes in average life span. The research team measured variations arising in ostensibly identical individuals, looking at how many worms died young versus how many made it to old age under each condition. This comprehensive view was important for capturing the dynamics and randomness in the aging process. In one sense, the findings were not surprising: different circumstances produced different life spans. Turning up the heat caused the worms to die quickly, and turning it up higher only increased that rate. Pictured as bell-shaped distributions, certain interventions produced a thinner, high-peaked bell, while others resulted in a more drawn-out and protracted bell.

Despite these obvious differences, the researchers found an unexpected uniformity among the curves. The various interventions seemed to affect the duration of life in the same way across all individuals in the same population, regardless of whether chance or randomness had a short or long life in store for them. No matter which genetic process or environmental factor the researchers targeted, all molecular causes of death seemed to be affected at once and to the same extent. These findings suggest that aging does not have a single discrete molecular cause but is rather a systemic process involving many components within a complex biological network. Perturb any node in the system, and you affect the whole thing.

Link: http://hms.harvard.edu/news/lifespan-machine-probes-cause-aging

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