Detection and measurement of abnormal posture under stressful conditions in nematode
ストレス条件下の線虫の姿勢異常の検出と計測
Ide, Kazunori*; Ishikawa, Tomoya*; Arai, Shingo*; Morioka, Tatsuya*; Kaneda, Hiroki*; 鈴木 芳代; 坂下 哲哉; 石井 直明*; 簗瀬 澄乃*
Ide, Kazunori*; Ishikawa, Tomoya*; Arai, Shingo*; Morioka, Tatsuya*; Kaneda, Hiroki*; Suzuki, Michiyo; Sakashita, Tetsuya; Ishii, Naoaki*; Yanase, Sumino*
Oxidative stress threatens cellular and extracellular targets including lipids, proteins and nucleic acids. As a result, oxidative stress causes or influence apoptosis, degenerative diseases and aging. Not only that, we found an abnormal posture in short-lived mutant such as , which is a paraquat (methylviologen)-sensitive strain, exposed to hyperoxia. In this study, we detected the hyperoxia-induced abnormal posture in mutant compared with wild-type N and long-lived strains. 4-day-old animals placed on a NGM agar plate with a fixed bacterial lawn were exposed to hyperoxia (90% of oxygen) overnight. After the exposure, some animals were immediately recorded as digital images with up to 400-fold magnification of the microscope. The images were analyzed using image processing software, Wriggle Tracker and Move-tr/2D, by a previously published method (Hattori et al., 2012). The body line was skeletonized and evenly divided into 12 segments. Subsequently, X- and Y-coordinates of each point on the body were acquired. To evaluate the posture of the body, we introduced a novel standard, namely the "posture index" as the absolute average of the relative angle, , between adjacent dividing points. As a result of this investigation, we can not only intuitively but also quantitatively and statistically understand a tendency of the behavior in a short-lived mutant under stressful conditions.