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Genetics of Intraspecies Variation in Avoidance Behavior Induced by a Thermal Stimulus in Caenorhabditis elegans.

Ghosh R, Bloom JS, Mohammadi A, Schumer ME, Andolfatto P, Ryu W, Kruglyak L - Genetics (2015)

Bottom Line: Individuals within a species vary in their responses to a wide range of stimuli, partly as a result of differences in their genetic makeup.Our results show that the escape behavior induced by thermal stimuli is composed of simpler behavioral components that are influenced by at least six distinct genetic loci.Our work sets the foundation for future studies of evolution of innate behaviors at the molecular and neuronal level.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics-Oncology, Baylor College of Medicine, Houston, Texas 77030.

No MeSH data available.


Comparison of Hawaii and Bristol strains in responses to thermal stimuli of various intensities. (A) Centroid speed of Bristol (orange) and Hawaii (blue) animals plotted against time for each ∆T. The red horizontal bar indicates duration of the pulse. Temperature increases above the baseline (ΔT) as a result of thermal pulses are indicated. The resulting speed profile corresponds to the indicated ∆T. Shading surrounding the time series represents 95% confidence intervals. (B) Ethogram of different behavioral states of the Bristol (left) and Hawaii (right) animals at indicated ΔT. The behavioral sequence of each animal over the duration of the assay at a given ΔT is shown. Each row represents behavior of a single animal over time. Blue, forward state; red, reversal; black, pause; green, omega turns.
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fig2: Comparison of Hawaii and Bristol strains in responses to thermal stimuli of various intensities. (A) Centroid speed of Bristol (orange) and Hawaii (blue) animals plotted against time for each ∆T. The red horizontal bar indicates duration of the pulse. Temperature increases above the baseline (ΔT) as a result of thermal pulses are indicated. The resulting speed profile corresponds to the indicated ∆T. Shading surrounding the time series represents 95% confidence intervals. (B) Ethogram of different behavioral states of the Bristol (left) and Hawaii (right) animals at indicated ΔT. The behavioral sequence of each animal over the duration of the assay at a given ΔT is shown. Each row represents behavior of a single animal over time. Blue, forward state; red, reversal; black, pause; green, omega turns.

Mentions: In agreement with previous studies (Stephens et al. 2008), we found that in unstimulated conditions and immediately (<0.2 sec) after exposure to thermal stimuli, Bristol animals move with a significantly lower speed (Welch two sample t-test, P < 0.0001) compared to the Hawaiian animals (Figure 2A, top). Upon experiencing the thermal pulse, both strains decelerate to a pause state and then accelerate away from the stimulus. However, the two strains showed distinct speed profiles during the avoidance response (Figure 2A). Initially (<0.5 sec from application of the thermal pulse), the Hawaiian animals moved forward at a greater speed compared to the Bristol animals, similar to observations under unstimulated conditions (Figure 2A, 2). Subsequently, the Bristol animals moved away from the stimulus significantly faster than the Hawaiian animals. After ∼3 sec, the speed differences between these two strains were similar to the prestimulus state, with the Hawaiian animals once again moving faster (Figure 2A, 2). Bristol and Hawaiian strains also differed in their probability of transition between different behavioral states, as well as in the duration of a given behavioral state (Figure 2B). At stimuli with higher intensities (∆T of 1°, 4.8°, or 9.1°), the differences in avoidance response between these two strains were smaller (Figure 2B). Because the parental strains differed most in their responses elicited by ∆T = 0.4°, we focused our studies of the genetic basis in avoidance behavior at this stimulus intensity.


Genetics of Intraspecies Variation in Avoidance Behavior Induced by a Thermal Stimulus in Caenorhabditis elegans.

Ghosh R, Bloom JS, Mohammadi A, Schumer ME, Andolfatto P, Ryu W, Kruglyak L - Genetics (2015)

Comparison of Hawaii and Bristol strains in responses to thermal stimuli of various intensities. (A) Centroid speed of Bristol (orange) and Hawaii (blue) animals plotted against time for each ∆T. The red horizontal bar indicates duration of the pulse. Temperature increases above the baseline (ΔT) as a result of thermal pulses are indicated. The resulting speed profile corresponds to the indicated ∆T. Shading surrounding the time series represents 95% confidence intervals. (B) Ethogram of different behavioral states of the Bristol (left) and Hawaii (right) animals at indicated ΔT. The behavioral sequence of each animal over the duration of the assay at a given ΔT is shown. Each row represents behavior of a single animal over time. Blue, forward state; red, reversal; black, pause; green, omega turns.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4574258&req=5

fig2: Comparison of Hawaii and Bristol strains in responses to thermal stimuli of various intensities. (A) Centroid speed of Bristol (orange) and Hawaii (blue) animals plotted against time for each ∆T. The red horizontal bar indicates duration of the pulse. Temperature increases above the baseline (ΔT) as a result of thermal pulses are indicated. The resulting speed profile corresponds to the indicated ∆T. Shading surrounding the time series represents 95% confidence intervals. (B) Ethogram of different behavioral states of the Bristol (left) and Hawaii (right) animals at indicated ΔT. The behavioral sequence of each animal over the duration of the assay at a given ΔT is shown. Each row represents behavior of a single animal over time. Blue, forward state; red, reversal; black, pause; green, omega turns.
Mentions: In agreement with previous studies (Stephens et al. 2008), we found that in unstimulated conditions and immediately (<0.2 sec) after exposure to thermal stimuli, Bristol animals move with a significantly lower speed (Welch two sample t-test, P < 0.0001) compared to the Hawaiian animals (Figure 2A, top). Upon experiencing the thermal pulse, both strains decelerate to a pause state and then accelerate away from the stimulus. However, the two strains showed distinct speed profiles during the avoidance response (Figure 2A). Initially (<0.5 sec from application of the thermal pulse), the Hawaiian animals moved forward at a greater speed compared to the Bristol animals, similar to observations under unstimulated conditions (Figure 2A, 2). Subsequently, the Bristol animals moved away from the stimulus significantly faster than the Hawaiian animals. After ∼3 sec, the speed differences between these two strains were similar to the prestimulus state, with the Hawaiian animals once again moving faster (Figure 2A, 2). Bristol and Hawaiian strains also differed in their probability of transition between different behavioral states, as well as in the duration of a given behavioral state (Figure 2B). At stimuli with higher intensities (∆T of 1°, 4.8°, or 9.1°), the differences in avoidance response between these two strains were smaller (Figure 2B). Because the parental strains differed most in their responses elicited by ∆T = 0.4°, we focused our studies of the genetic basis in avoidance behavior at this stimulus intensity.

Bottom Line: Individuals within a species vary in their responses to a wide range of stimuli, partly as a result of differences in their genetic makeup.Our results show that the escape behavior induced by thermal stimuli is composed of simpler behavioral components that are influenced by at least six distinct genetic loci.Our work sets the foundation for future studies of evolution of innate behaviors at the molecular and neuronal level.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics-Oncology, Baylor College of Medicine, Houston, Texas 77030.

No MeSH data available.