A high throughput and sensitive method correlates neuronal disorder genotypes to Drosophila larvae crawling phenotypes

Figures & data

Figure 2. Fragile X larvae crawl more slowly and turn more often. (A) The Mean Squared Displacement (MSD) for crawling larvae from the Fragile X model (dfmr1⁴) is lower than that for wild type larvae w[1118] indicating crawling defects. The smaller y-intercept, inset in (A), is indicative of a smaller mean velocity. Larvae from the Drifter strain (Df), which have decreased levels of the ion channel pickpocket1 that is over abundant in Fragile X individuals, show an opposite trend demonstrating the dynamic range of the method. (B) The Direction Autocorrelation (DAC) shows that the dfmr1⁴ larvae turn more often than wild type larvae at small times and that the Df larvae turn significantly less. Error is standard error of the mean and is shown as a shadowed region around the trace for clarity. MSD error is smaller than the data point symbols and not shown on the logarithmic plot for clarity. Symbols and colors: cyan circles are Drifters, black squares are wild type and magenta triangles are Fragile X larvae, arranged in this order from top to bottom in the MSD plot in (A). (Number of larvae tracked: WT (25), dfmr1⁴ (24), Drifter (17))

Figure 3. Both GSK-3 overexpression and reduction lead to dosage-dependent impairment of the crawling behavior. The MSD and DAC plots show that overexpression of dGSK-3 leads to a smaller velocity (A, inset) and more frequent turns (B). Two classes of larvae with different degrees of dGSK-3 reduction lead to decrease in velocity and increase in turning frequency. The severity of the phenotype correlates with the expression levels of dGSK-3. The ’SGG severe’ express less dGSK-3 than both wild type and ‘SGG moderate’ larvae and show a smaller velocity (A) as well as a larger turning frequency (B). Error is standard error of the mean and is shown as a shadowed region around the trace for clarity. MSD error is smaller than the data point symbols and not shown on the logarithmic plot for clarity. Symbols and colors: black squares are wild type, red diamonds are increased Sgg, green circles are Sgg moderate and purple triangles are Sgg severe larvae, arranged in this order from top to bottom in the MSD plot in (A). [Number of larvae tracked: WT (22), Increased SGG (19), SGG Moderate (24), SGG Severe (17)]

Figure 1. Representative larva tracks alongside a schematic representation of the experimental setup. The inset shows the experimental setup which consists of a camera and lens fixed on an aluminum stand 45 cm away from the Petri dish on which the larvae crawl. Larval tracks for the Fragile X model (dfmr1⁴), Drifters (Df), and their corresponding wild-type strain (w[1118]) show that differences cannot always be visible in the tracks unless the phenotype is extreme as in the case of the Drifters. All tracks represent 20 min of crawling.

Fritz H, Said S, Weimerskirch H. Scale-dependent hierarchical adjustments of movement patterns in a long-range foraging seabird. Proc Biol Sci 2003; 270:1143 - 8; http://dx.doi.org/10.1098/rspb.2003.2350; PMID: 12816652

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