Optimized criteria for locomotion-based healthspan evaluation in C. elegans using the WorMotel system

Abstract

Getting a grip on how we may age healthily is a central interest of biogerontological research. To this end, a number of academic teams developed platforms for life-and healthspan assessment in Caenorhabditis elegans. These are very appealing for medium-to high throughput screens, but a broader implementation is lacking due to many systems relying on custom scripts for data analysis that others struggle to adopt. Hence, user-friendly recommendations would help to translate raw data into interpretable results. The aim of this communication is to streamline the analysis of data obtained by the WorMotel, an economically and practically appealing screening platform, in order to facilitate the use of this system by interested researchers. We here detail recommendations for the stepwise conversion of raw image data into activity values and explain criteria for assessment of health in C. elegans based on locomotion. Our analysis protocol can easily be adopted by researchers, and all needed scripts and a tutorial are available in S1 and S2 Files. OPEN ACCESS Citation: Jushaj A, Churgin M, Yao B, De La Torre M, Fang-Yen C, Temmerman L (2020) Optimized criteria for locomotion-based healthspan evaluation in C. elegans using the WorMotel system. PLoS ONE 15(3): e0229583. https://doi.org/10.

High Temporal Resolution Measurements of Movement Reveal Novel Early-Life Physiological Decline in C. elegans

“…Optimal protocols may differ for other longitudinal observation systems in which many identifiable individuals can be simultaneously observed at once [12,40]. Last, we examined unstimulated movement only, which may be less sensitive for observing age-related changes across life [12,32].…”

“…Because minute-scale recordings capture an appreciable fraction of total movement, we used these measures to determine how movement varies during the first days of early adulthood in C. elegans. The first 4-6 days of adulthood are typically known as a period of vigorous activity prior to the beginning of an overt, qualitative decline in movement rates [7,[11][12][13]32].…”

“…Second, we defined a "Daily Video" protocol that measures 15 minutes of movement at 1 fps, once a day per individual. This is analogous to standard plate assays in which animals are recorded at high frame rate for a fixed amount of time each day [14,23,32,34]. Unlike the "Single Snapshot" protocol which we can readily examine by subsampling our continuous 1 fpm imaging data, we cannot directly produce a dataset equivalent to the "Daily Video" protocol from the images obtained.…”

Phenotypic Screening in C. elegans as a Tool for the Discovery of New Geroprotective Drugs

“…Therefore, the development of systems that incorporate the automatic quantification of both healthspan parameters and lifespan will be paramount. Some microfluidics-based [302] and NGM-based [233,277] automated screening platforms already enable the simultaneous determination of lifespan and healthspan.…”

“…The time of death is recorded as the last moment of movement [ 263 ]. WorMotel can also be used to evaluate activity-based healthspan measures [ 263 , 277 ]. Software for the WorMotel is freely available ( ).…”