title: A Run-Length Encoding Approach for Path Analysis of C. elegans Search Behavior.
abstract: The nematode Caenorhabditis elegans explores the environment using a combination of different movement patterns, which include straight movement, reversal, and turns. We propose to quantify C. elegans movement behavior using a computer vision approach based on run-length encoding of step-length data. In this approach, the path of C. elegans is encoded as a string of characters, where each character represents a path segment of a specific type of movement. With these encoded string data, we perform k-means cluster analysis to distinguish movement behaviors resulting from different genotypes and food availability. We found that shallow and sharp turns are the most critical factors in distinguishing the differences among the movement behaviors. To validate our approach, we examined the movement behavior of tph-1 mutants that lack an enzyme responsible for serotonin biosynthesis. A k-means cluster analysis with the path string-encoded data showed that tph-1 movement behavior on food is similar to that of wild-type animals off food. We suggest that this run-length encoding approach is applicable to trajectory data in animal or human mobility data.
authors.affiliation: School of Computing, College of Computing and Digital Media, DePaul University, Chicago, IL 60604, USA.
authors.forename: Li
authors.identifier: 0000-0002-9681-2606
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University, North Chicago, IL 60064-3095, USA.
authors.forename: Hongkyun
authors.initials: H
authors.lastname: Kim
authors.affiliation: School of Computing, College of Computing and Digital Media, DePaul University, Chicago, IL 60604, USA.
authors.forename: Jacob
authors.initials: J
authors.lastname: Furst
authors.affiliation: School of Computing, College of Computing and Digital Media, DePaul University, Chicago, IL 60604, USA.
authors.forename: Daniela
authors.identifier: 0000-0002-2165-7234
authors.initials: D
authors.lastname: Raicu
mesh_terms: D000465:Algorithms; D000818:Animals; D001070:Appetitive Behavior; D001522:Behavior, Animal; D017173:Caenorhabditis elegans / Q000502:physiology*; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D005247:Feeding Behavior; D005838:Genotype; D000069550:Machine Learning; D009068:Movement; D010363:Pattern Recognition, Automated; D012984:Software