Untitled

Abstract

A new assay was designed, named checker, that measures the individual response to light in the fruitfly Drosophila melanogaster larva. In this assay the Drosophila larva apparently modulates its pattern of locomotion when faced with a choice between a dark and lit environment by orienting its movement towards the dark environment. We show that, in this assay, a response to light can be measured as an increase in residence time in the dark versus the lit quadrant. Mutations that disrupt phototransduction in the adult Drosophila abolish the larval response to light, demonstrating that this larval visual function is similar to that of the adult fly. Similarly, no response to light was detected in strains where the larval visual system (photoreceptors and target area) was disrupted by a mutation in the homeobox containing gene sine oculis (so) gene. Ablation of photoreceptors by the targeted expression of the cell death gene hid under the control of the photoreceptor-specific transcription factor glass (gl) abolishes this response entirely. Finally, we demonstrate that this response to light can be mediated by rhodopsins other than the blue absorbing Rh1.

Fine Thermotactic Discrimination between the Optimal and Slightly Cooler Temperatures via a TRPV Channel in Chordotonal Neurons

“…Wild-type larvae express rhodopsins (Sprecher et al, 2007), which are classical G-protein coupled receptors. Consequently, in the absence of ChR2, wild-type larvae display an aversive response to light (Hassan et al, 2000). To eliminate the endogenous light response, we tested the effects of introducing the iav-GAL4 and UAS-ChR2 in a norpA P24 background, which disrupts a phospholipase C critical for the larval photoresponse (Hassan et al, 2000).…”

Age- and Wavelength-Dependency of Drosophila Larval Phototaxis and Behavioral Responses to Natural Lighting Conditions

“…More than 35 years ago it was reported that Drosophila melanogaster larvae are photophilic in early stages, photoneutral in later stages, and photonegative in the end of the larval life (Manning and Markow, 1981; Markow, 1981). In contrast to this early description, a general consensus nowadays in most of the reports is that Drosophila larvae are photophobic during early stages of development (Godoy-Herrera et al, 1992; Sawin-McCormack et al, 1995; Busto et al, 1999; Warrick et al, 1999; Hassan et al, 2000; Mazzoni et al, 2005; Scantlebury et al, 2007; Gong, 2009; Keene et al, 2011; von Essen et al, 2011; Yamanaka et al, 2013). However, how phototaxis is altered or maintained during later stages remains debated.…”

“…Larval navigation is based on a combination of forward movements (called runs) and reorientations (called turns) (Luo et al, 2010; Gomez-Marin et al, 2011; Lahiri et al, 2011; Gershow et al, 2012; Kane et al, 2013). Changes in light-intensity elicit turning behavior (Busto et al, 1999; Hassan et al, 2000, 2005; Scantlebury et al, 2007; Kane et al, 2013). During these turns larvae move their head from one side to the other (called head-sweep) to probe the environment (Busto et al, 1999; Hassan et al, 2000, 2005; Scantlebury et al, 2007; Kane et al, 2013).…”

“…Changes in light-intensity elicit turning behavior (Busto et al, 1999; Hassan et al, 2000, 2005; Scantlebury et al, 2007; Kane et al, 2013). During these turns larvae move their head from one side to the other (called head-sweep) to probe the environment (Busto et al, 1999; Hassan et al, 2000, 2005; Scantlebury et al, 2007; Kane et al, 2013). Thus information about the light intensity is integrated temporally and not spatially (Kane et al, 2013).…”

Turns with multiple and single head cast mediate Drosophila larval light avoidance

“…In another assay, a larva crosses light/dark boundaries on a checkerboard test. In this case, the light/dark choice is encountered frequently [8, 12]. In one other assay, light is shed on crawling larvae and their responses to on/off switch of light are monitored and recorded [8, 13, 14, 15].…”