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[Q. Neuroscience-42]

Study on molecular mechanisms of gait switching in C.

elegans

Kyeong Min Moon¹, Jihye Cho¹, Jimin Kim¹, Kyuhyung Kim¹

¹Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea

Gait is the movement pattern of the animals. Most animals exhibit multiple forms of gaits and switch gaits
depending upon external and/or internal conditions. However, molecular mechanisms underlying gait switching are
not fully understood. The nematode Caenorhabditis elegans is a good model system that allows us to study gait

switching, because animals exhibit well-defined locomotive behaviors or gaits which are flexible. For example,

animals crawl on solid surfaces with low frequency and short wavelength (Karbowski J, et al., 2006), and swim under
liquid with high frequency and long-wavelength (Korta et al., 2007; Pierce-Shimomura et al., 2008). To identify the
molecular mechanisms of gait switching in C. elegans, we performed EMS mutagenesis and isolated ten mutants

(lsk56-65), which are defective in crawl-to-swim switching or swimming. We classified these mutants into two groups
depending on their behavior phenotypes. The first group of five mutants (lsk56,57,59,60,64) exhibited delayed crawl-

to-swim switching and severely decreased swimming frequency. The second group of five mutants (lsk58,61,62,63,65)
exhibited normal crawl-to-swim switching, but decreased swimming frequency. Currently, we are performing

chromosomal mapping to clone newly found swimming defective mutants.