Quantification of gait parameters in freely walking wild type and sensory deprived Drosophila melanogaster
- Columbia University, USA
Figures
Figure 1 with 2 supplements
fTIR apparatus and FlyWalker software.
(A). Schematic of the fTIR optical effect. LED light sources are located at the edges of an optical glass and light propagates within the glass via internal reflection. Tarsal contacts lead to light …
Figure 1—figure supplement 1
Additional information on fTIR apparatus.
(A). Detailed schematic of the fTIR apparatus. Red dashed line shows position of the cross-section image in panel (B). (B) Cross-section of schematic at red dashed line in panel (A). (C) Photograph …
Figure 1—figure supplement 2
FlyWalker program.
(A). Screenshot of the FlyWalker graphical user interface used to edit fTIR videos. (B). Screenshot of the FlyWalker parameters window.
Figure 2 with 2 supplements
General walking parameters.
(A). Speed histogram of 71 videos recorded for wild type flies, with 2 mm/s bins. Average speeds vary between 7.2 and 44.7 mm/s, with 28 mm/s the most represented speed. Speeds at ∼20 mm/s are …
Figure 2—figure supplement 1
Gait definitions.
For each leg, swing phases are represented in black and stance phases are represented in white (from top to bottom: right hind (RH); right mid (RM); right front (RF); left hind (LH); left middle …
Figure 2—figure supplement 2
Gait parameters by segment.
(A)–(D). Each column corresponds to the legs in a particular segment. Graphical fits are represented by blue lines. (A) Stance duration. (B) Swing duration. (C) Step length. (D) Swing speed.
Figure 3 with 3 supplements
Spatial parameters.
(A). Stance traces. Representative plot of an animal walking at 28.82 mm/s. Traces are generated by the position of the stance phase footprints relative to the body center (set at 0.0,0.0). For each …
Figure 3—figure supplement 1
Representative examples of stance traces and corresponding stance linearity values.
A less linear stance trace (e.g., (A′) compared to (A)) corresponds a higher stance linearity value.
Figure 3—figure supplement 2
AEP and PEP clustering values for all segments as a function of speed.
Linear trend lines for AEP and PEP versus average speed are shown as blue and red lines, respectively.
Figure 3—figure supplement 3
AEP and PEP clustering values for each segment as a function of speed.
(A). Linear trend lines for AEP and PEP are represented as blue and red lines, respectively. (A) forelegs; (A′) midlegs; (A″) hindlegs. (B). Boxplots of the data presented in (A). Data were grouped …
Figure 4 with 2 supplements
Gait parameters.
(A),(B). Upper panels show the step pattern for representative videos of animals walking at 44.7 (A) and at 14.6 mm/s (B). For each leg swing phases are represented in black (from top to bottom: …
Figure 4—figure supplement 1
Gait features.
(A)–(C). Walking gaits and leg combinations. Each leg can be either in a swing or stance phase, represented by white or black circles, respectively. Underneath each combination the corresponding …
Figure 4—figure supplement 2
Gait index plot.
(A). Average gait index as a function of speed. Each point corresponds to the average of all frames in a video (Figure 4A‴,B‴). (B). Instantaneous speed, gait map and gait index plots for data …
Figure 5 with 2 supplements
Coordination parameters.
(A). Method to calculate footprint alignment. For each set of footprints, the projection points along the displacement axis (horizontal black arrow) are calculated. Footprint alignment corresponds …
Figure 5—figure supplement 1
Representative images of footprints with different footprint alignment values.
https://doi.org/10.7554/eLife.00231.020
Figure 5—figure supplement 2
Radial plots of adjacent ipsilateral leg phases comparing slow and fast walking animals.
Individual data points for slow and fast flies are represented by blue circles and red triangles, respectively. Mean r vectors for slow and fast animals are represented by blue and red arrows, …
Figure 6
Effects of sensory deprivation on walking.
(A). Expression pattern driven by nanchung-Gal4. Genotype: F-Gal4, UAS-GFP. (B). GFP expression under combinatorial control of 5-40-Gal4 and dacRE-flp. Genotype: 5-40-Gal4, dacRE-flp, UAS-FRT-stop-FR…
Figure 7
Quantification of gait parameters in sensory deprived animals.
(A). Stance traces of three representative animals walking at a similar speed. For simplicity, only left stance traces are shown. Traces for sensory deprived genotypes display a longer step length; …
Videos
Video 1
Unprocessed fTIR video.
Video 2
Processed video by FlyWalker.
Video 3
Processed video of 5-40Leg>TNT fly.
Tables
Table 1
Gait combinations in three speed classesa
| Slow [≤19.9 mm/s] | Medium [20–33.9 mm/s] | Fast [≥34 mm/s] | |||
| Tripod | 31.37 | Tripod | 51.63 | Tripod | 64.98 |
| Tetrapod | 25.45 | Tetrapod | 15.90 | Tetrapod | 7.26 |
| Total | 56.82 | Total | 67.54 | Total | 72.24 |
| Additional combinations | Additional combinations | Additional combinations | |||
| 111110 | 8.27 | 111111 | 4.76 | 111011 | 4.89 |
| 110111 | 7.60 | 111110 | 4.61 | 111111 | 4.25 |
| 111111 | 6.38 | 011111 | 4.30 | 011111 | 4.07 |
| 111011 | 5.62 | 111011 | 4.26 | 010111 | 3.36 |
| 011111 | 5.03 | 010111 | 3.84 | 111010 | 2.80 |
| 010111 | 2.47 | 110111 | 3.79 | 110111 | 2.32 |
| 111010 | 2.45 | 111010 | 2.91 | 111110 | 1.29 |
| 101111 | 1.94 | 101111 | 0.71 | 011011 | 1.25 |
| 111101 | 1.69 | 011011 | 0.52 | 011010 | 0.69 |
| Pentapod | 30.15 | Pentapod | 14.37 | Pentapod | 13.33 |
| 3 gaits combinedb | 86.97 | 3 gaits combinedb | 81.91 | 3 gaits combinedb | 85.57 |
| Totalc | 98.3 | Totalc | 97.2 | Totalc | 97.15 |
-
a
Values are expressed as percentage (%). Leg order in combination: LF LM LH RF RM RH. 1, footprint present; 0, footprint is absent.
-
b
The sum of tripod, tetrapod, and pentapod gaits.
-
c
The sum of all gait patterns listed in the table.
Table 2
Multiple regression models for wild type versus sensory-deprived fliesa
| Wild type vs nan36a | |||||||||||||||||||
| Step length (Figure 7B) | Stance linearity (Figure 7C) | Swing duration (Figure 7E) | Swing speed (Figure 7G) | Stance duration (Figure 7F) | Tripod index (Figure 6D) | ||||||||||||||
| Coef | SE | p-value | Coef | SE | p-value | Coef | SE | p-value | Coef | SE | p-value | Coef | SE | p-value | Coef | SE | p-value | ||
| WT y intercept | 746.7 | 93.8 | 0.0 | 291.6 | 32.6 | 0.0 | 3.6 × 10−2 | 1.9 × 10−3 | 0.0 | 19.1 | 2.1 | 0.0 | 2.3 × 10−1 | 1.2 × 10−2 | 0.0 | −9.2 × 10−4 | 4.2 × 10−2 | 0.982 | |
| Δ y intercept | 587.4 | 270.5 | 0.0 | 349.8 | 96.4 | 0.0 | 2.2 × 10−2 | 5.2 × 10−3 | 0.0 | −4.5 | 5.9 | 0.451 | 1.9 × 10−1 | 3.4 × 10−2 | 0.0 | −4.1 × 10−1 | 1.2 × 10−1 | 0.001 | |
| WT slope | 47.2 | 3.3 | 0.0 | −70.9 | 9.9 | 0.0 | −1.3 × 10−4 | 6.4 × 10−5 | 0.043 | 0.6 | 0.1 | 0.0 | −5.4 × 10−2 | 3.5 × 10−3 | 0.0 | 1.8 × 10−2 | 1.4 × 10−3 | 0.0 | |
| Δ Slope | −11.3 | 12.9 | 0.4 | −89.1 | 32.1 | 0.007 | −8.4 × 10−4 | 2.5 × 10−4 | 0.001 | 0.5 | 0.3 | 0.115 | −1.6 × 10−2 | 4.8 × 10−3 | 0.002 | 1.6 × 10−2 | 5.6 × 10−3 | 0.006 | |
| Wild type versus 5-40Leg>TNT | |||||||||||||||||||
| WT y intercept | 746.7 | 93.8 | 0.0 | 291.6 | 34.0 | 0.0 | 3.6 × 10−2 | 1.9 × 10−3 | <0.001 | 19.1 | 2.1 | <0.001 | 2.3 × 10−1 | 1.2 × 10−2 | 0.0 | −9.2 × 10−4 | 4.3 × 10−2 | 0.983 | |
| Δ y intercept | 622.8 | 295.3 | 0.038 | 242.2 | 115.7 | 0.039 | 1.7 × 10−2 | 1.0 × 10−3 | <0.001 | 10.5 | 6.4 | 0.1 | 1.6 × 10−1 | 4.1 × 10−2 | 0.0 | −3.6 × 10−1 | 1.4 × 10−1 | 0.009 | |
| WT slope | 47.2 | 3.2 | 0.0 | −70.9 | 10.3 | 0.0 | −1.0 × 10−4 | 6.0 × 10−5 | 0.04 | 0.7 | 0.1 | <0.001 | −5.4 × 10−2 | 3.7 × 10−3 | 0.0 | 1.8 × 10−2 | 1.5 × 10−3 | 0.0 | |
| Δ Slope | 11.4 | 15.6 | 0.465 | −54.8 | 39.7 | 0.17 | −2.4 × 10−5 | 3.1 × 10−4 | 0.94 | −0.5 | 0.3 | 0.12 | −4.4 × 10−2 | 1.4 × 10−2 | 0.003 | 1.6 × 10−2 | 7.1 × 10−3 | 0.032 | |
-
a
Coef stands for the estimated regression coefficient, SE represents its standard error. In this model we log transformed average speed for parameters that were non-linear with respect to speed (step linearity and stance duration). WT y intercept indicates the y intercept for wild type. Δ y intercept indicates the difference in the y intercept between the experimental condition and wild type. WT slope reports the slopes of the wild type regression lines. p-values >0.05 are in bold italics; those <0.05 are in italics underlined. If Δ slope is >0.05 (bold italics) the regression curves are considered non-interacting (∼parallel). If Δ y intercept is <0.05 (italics underlined), the parameter is considered different from WT.
