Boundary preference in small arenas in CS and w1118 flies.

<p>(A) Composite image of eight superimposed frames indicating the locations of single fly with 0.2s interval. The black outer circle indicates the edge of the arena. The red inner circle indicates a standard border delineating the perimeter zone. Black and red circles are spaced apart by half the length of the fly. White lines show the fly trajectory. Red cross (×) indicates the center of arena. If the center of the fly is on the red circle or within the area between two circles, the fly is deemed to be on the perimeter. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135825#sec002" target="_blank">Materials and Methods</a> for further description. (B) Illustration of fly centers (black dots) for 300 locations within 1min activity in a small arena. The standard border (red circle) and the center of arena (red cross) are indicated for reference. (C) Positions of a single CS and w1118 fly for 5 consecutive minutes in small arena. (D, E) %TOP during first five consecutive minutes for CS (n = 8) and w1118 (n = 8) male (D) or female (E) flies. The <i>P</i> values are the statistical results of repeated measures ANOVA comparing genotypes.