Running Worms: C. elegans Self-Sorting by Electrotaxis

Abstract

The nematode C. elegans displays complex dynamical behaviors that are commonly used to identify relevant phenotypes. Although its maintenance is straightforward, sorting large populations of worms when looking for a behavioral phenotype is difficult, time consuming and hardly quantitative when done manually. Interestingly, when submitted to a moderate electric field, worms move steadily along straight trajectories. Here, we report an inexpensive method to measure worms crawling velocities and sort them within a few minutes by taking advantage of their electrotactic skills. This method allows to quantitatively measure the effect of mutations and aging on worm's crawling velocity. We also show that worms with different locomotory phenotypes can be spatially sorted, fast worms traveling away from slow ones. Group of nematodes with comparable locomotory fitness could then be isolated for further analysis. C. elegans is a growing model for neurodegenerative diseases and using electrotaxis for self-sorting can improve the high-throughput search of therapeutic bio-molecules.

Age-Related Changes in Locomotor Performance Reveal a Similar Pattern forCaenorhabditis elegans,Mus domesticus,Canis familiaris,Equus caballus, andHomo sapiens

“…Based on these results, we hypothesize that these age-related patterns are common features of the relationship between age and locomotor performance in a wide range of organisms. The shape of the patterns seems to match descriptions of other age-related locomotor performances in different species, such as flight performances in Drosophila (31), honeybees (32), and codling moths (33), maximal sprint speed in dogs and horses (34)(35)(36), physical activity in different rodents and monkeys (16,27,28), grip strength in mouse lemurs (15), hunting rates and success in wolves (37), swimming speed in zebrafish (38), and voluntary activity and electrotactic behavior in C. elegans (29,39). Likewise, other performance traits might follow a similar pattern, such as biting force in mouse lemur (40), cognitive performances in Rhesus monkey (41), attentiveness in domestic dogs (42), pharynx pumping rate in C. elegans (43), and perhaps even photosynthetic yield in cotton leaves (44).…”

“…We used the previously described electrotaxis device (29). Worms were tracked with a camera CCD (Edmund Optics, EO-0813M) fitted with a 10× lens (Computar MLH 10×).…”

Galvanotaxis of Caenorhabditis elegans: current understanding and its application in improving research

“…A small setup was introduced by Manière et al (2011) to screen for mutants defective of locomotion and to study the effect of mutation or aging on worm mobility by quantitatively analyzing the worm crawling velocity using galvanotaxis behavior [40]. Salam et al (2013) used the electrosensory behavior of C. elegans in microfluidic channel to study the behavior of mutants that effect sensory and dopaminergic neurons, thereby proving that electrotaxis assays can be a reliable method to study neuromuscular activity.…”

The ESCRT-II proteins are involved in shaping the sarcoplasmic reticulum in C. elegans

“…6A) (data not shown) only during late larval development. To further study and quantify the locomotion defect, we performed an electrotaxis analysis (Maniere et al, 2011) to check that vps-22 and vps-36 heterozygous animals had wild-type locomotion (Fig. 6B).…”

“…Electrotaxis was performed according to Maniere et al (2011) with some modifications to facilitate L3 and L4 larvae sorting. The pre-running gel solution was 2% agar, 0.25 mM NaCl.…”