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Large-scale assessment of olfactory preferences and learning in Drosophila melanogaster: behavioral and genetic components.

Versace E, Reisenberger J - PeerJ (2015)

Bottom Line: Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples.Consistent with previous results, we show that flies have a preference for orange vs. apple odor.We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut für Populationsgenetik , Vetmeduni, Vienna , Austria ; Center for Mind/Brain Sciences, University of Trento , Rovereto , Italy.

ABSTRACT
In the Evolve and Resequence method (E&R), experimental evolution and genomics are combined to investigate evolutionary dynamics and the genotype-phenotype link. As other genomic approaches, this methods requires many replicates with large population sizes, which imposes severe restrictions on the analysis of behavioral phenotypes. Aiming to use E&R for investigating the evolution of behavior in Drosophila, we have developed a simple and effective method to assess spontaneous olfactory preferences and learning in large samples of fruit flies using a T-maze. We tested this procedure on (a) a large wild-caught population and (b) 11 isofemale lines of Drosophila melanogaster. Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples. Consistent with previous results, we show that flies have a preference for orange vs. apple odor. With our procedure wild-derived flies exhibit olfactory learning in the absence of previous laboratory selection. Furthermore, we find genetic differences in the olfactory learning with relatively high heritability. We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

No MeSH data available.


Related in: MedlinePlus

Conditioned orange odor choices for a population of ten inbred lines and learning score.(A) Proportion of orange odor choices for flies conditioned with Orange aversive/Apple palatable (O-/A) and Apple aversive/Orange palatable (A-/O) in the overall sample of ten inbred lines. (B) Learning score: difference in the proportion of orange odor choices between flies conditioned on A-/O (Apple aversive, Orange palatable) and O-/A (Orange aversive, Apple palatable).
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fig-5: Conditioned orange odor choices for a population of ten inbred lines and learning score.(A) Proportion of orange odor choices for flies conditioned with Orange aversive/Apple palatable (O-/A) and Apple aversive/Orange palatable (A-/O) in the overall sample of ten inbred lines. (B) Learning score: difference in the proportion of orange odor choices between flies conditioned on A-/O (Apple aversive, Orange palatable) and O-/A (Orange aversive, Apple palatable).

Mentions: In the learning assay, the overall distribution of the orange odor choices was significantly different from the normal distribution (Shapiro–Wilk normality test: W = 0.98, p = 0.005) and we analyzed the data using non parametric tests (Wilcoxon signed-rank test and Kruskal–Wallis test). Overall, after the conditioning procedure the ten responsive lines showed a preference for orange odor (mean = 0.59, Wilcoxon signed-rank test, V = 8630, p = 9.159x10−6), Fig. 5A. No significant difference in the overall choices was observed between the olfactory preference and the learning assay (W = 13655.5, p = 0.30). Differently from the olfactory preference assay though, significant differences in the proportion of orange choices were apparent between the two conditioning treatments (A-/O vs. O-/A: Kruskal–Wallis Chi square: 34.93, p = 3.424 x10−9) (Fig. 5A), and we documented a significant learning effect (Fig. 5B). We also detected significant differences in the proportion of orange choices between lines (Kruskal–Wallis Chi square: 23.45, p = 0.005).


Large-scale assessment of olfactory preferences and learning in Drosophila melanogaster: behavioral and genetic components.

Versace E, Reisenberger J - PeerJ (2015)

Conditioned orange odor choices for a population of ten inbred lines and learning score.(A) Proportion of orange odor choices for flies conditioned with Orange aversive/Apple palatable (O-/A) and Apple aversive/Orange palatable (A-/O) in the overall sample of ten inbred lines. (B) Learning score: difference in the proportion of orange odor choices between flies conditioned on A-/O (Apple aversive, Orange palatable) and O-/A (Orange aversive, Apple palatable).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562235&req=5

fig-5: Conditioned orange odor choices for a population of ten inbred lines and learning score.(A) Proportion of orange odor choices for flies conditioned with Orange aversive/Apple palatable (O-/A) and Apple aversive/Orange palatable (A-/O) in the overall sample of ten inbred lines. (B) Learning score: difference in the proportion of orange odor choices between flies conditioned on A-/O (Apple aversive, Orange palatable) and O-/A (Orange aversive, Apple palatable).
Mentions: In the learning assay, the overall distribution of the orange odor choices was significantly different from the normal distribution (Shapiro–Wilk normality test: W = 0.98, p = 0.005) and we analyzed the data using non parametric tests (Wilcoxon signed-rank test and Kruskal–Wallis test). Overall, after the conditioning procedure the ten responsive lines showed a preference for orange odor (mean = 0.59, Wilcoxon signed-rank test, V = 8630, p = 9.159x10−6), Fig. 5A. No significant difference in the overall choices was observed between the olfactory preference and the learning assay (W = 13655.5, p = 0.30). Differently from the olfactory preference assay though, significant differences in the proportion of orange choices were apparent between the two conditioning treatments (A-/O vs. O-/A: Kruskal–Wallis Chi square: 34.93, p = 3.424 x10−9) (Fig. 5A), and we documented a significant learning effect (Fig. 5B). We also detected significant differences in the proportion of orange choices between lines (Kruskal–Wallis Chi square: 23.45, p = 0.005).

Bottom Line: Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples.Consistent with previous results, we show that flies have a preference for orange vs. apple odor.We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut für Populationsgenetik , Vetmeduni, Vienna , Austria ; Center for Mind/Brain Sciences, University of Trento , Rovereto , Italy.

ABSTRACT
In the Evolve and Resequence method (E&R), experimental evolution and genomics are combined to investigate evolutionary dynamics and the genotype-phenotype link. As other genomic approaches, this methods requires many replicates with large population sizes, which imposes severe restrictions on the analysis of behavioral phenotypes. Aiming to use E&R for investigating the evolution of behavior in Drosophila, we have developed a simple and effective method to assess spontaneous olfactory preferences and learning in large samples of fruit flies using a T-maze. We tested this procedure on (a) a large wild-caught population and (b) 11 isofemale lines of Drosophila melanogaster. Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples. Consistent with previous results, we show that flies have a preference for orange vs. apple odor. With our procedure wild-derived flies exhibit olfactory learning in the absence of previous laboratory selection. Furthermore, we find genetic differences in the olfactory learning with relatively high heritability. We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

No MeSH data available.


Related in: MedlinePlus