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- Moghadam, Neda N., et al.
(författare)
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Effects of photoperiod on life-history and thermal stress resistance traits across populations of Drosophila subobscura
- 2019
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Ingår i: Ecology and Evolution. - : WILEY. - 2045-7758. ; 9:5, s. 2743-2754
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Organisms use environmental cues to match their phenotype with the future availability of resources and environmental conditions. Changes in the magnitude and frequency of environmental cues such as photoperiod and temperature along latitudes can be used by organisms to predict seasonal changes. While the role of temperature variation on the induction of plastic and seasonal responses is well established, the importance of photoperiod for predicting seasonal changes is less explored. Materials and methods Here we studied changes in life-history and thermal stress resistance traits in Drosophila subobscura in response to variation in photoperiod (6:18, 12:12 and 18:6 light:dark cycles) mimicking seasonal variations in day length. The populations of D. subobscura were collected from five locations along a latitudinal gradient (from North Africa and Europe). These populations were exposed to different photoperiods for two generations, whereafter egg-to-adult viability, productivity, dry body weight, thermal tolerance, and starvation resistance were assessed. Results We found strong effects of photoperiod, origin of populations, and their interactions on life-history and stress resistance traits. Thermal resistance varied between the populations and the effect of photoperiod depended on the trait and the method applied for the assessment of thermal resistance. Perspectives Our results show a strong effect of the origin of population and photoperiod on a range of fitness-related traits and provide evidence for local adaptation to environmental cues (photoperiod by population interaction). The findings emphasize an important and often neglected role of photoperiod in studies on thermal resistance and suggest that cues induced by photoperiod may provide some buffer enabling populations to cope with a more variable and unpredictable future climate.
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| 2. |
- Pertoldi, Cino, et al.
(författare)
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The Novel Concept of "Behavioural Instability" and Its Potential Applications
- 2016
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Ingår i: Symmetry. - : MDPI AG. - 2073-8994. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- The concept of developmental instability (DI) is a well-known indicator of environmental and genetic stress and is often investigated using various indices such as fluctuating asymmetry, directional asymmetry, antisymmetry and phenotypic variance. Investigations dealing with DI are using morphometric traits. The aim of this investigation is to present the novel concept of behavioural instability in which the trait measured is a behavioural trait. We apply the conventional indices used for the estimation of developmental instability on directional movement-clockwise (CW) and counter-clockwise (CCW) movement of 19 highly inbred lines of Drosophila melanogaster tested in a circular arena. We show that it is possible to quantify behavioural instability using the indices traditionally used to investigate DI. Results revealed several significant differences among lines, depending on the index utilized. The perspectives of utilizing the concept in biological research such as toxicology, evolutionary and stress biology are discussed.
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| 3. |
- Savic Veselinovic, Manila, et al.
(författare)
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Local adaptation at fine spatial scale through chromosomal inversions and mito-nuclear epistasis : Findings in Drosophila subobscura (Diptera: Drosophilidae)
- 2019
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Ingår i: European Journal of Entomology. - : Biology Centre, AS CR. - 1210-5759 .- 1802-8829. ; 116, s. 492-503
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Tidskriftsartikel (refereegranskat)abstract
- To explore local adaptation in wild populations at a fine spatial scale we characterized the genetic variability of eight closely located populations of Drosophila subobscura and its associations with microhabitat environmental conditions. Three different genetic markers were assessed: chromosomal inversions, a SNP of mitochondrial ND5 gene and nuclear microsatellites. Population genetic analyses of chromosomal variability revealed significant genetic differentiation between these populations. Gene arrangement frequencies on the E chromosome contributed most to these differences. We also investigated role of mitonuclear epistasis in mitochondrial genome differentiation and revealed weak linkage disequilibrium (LD) exclusively between O-3+(4) inversion arrangement and mitochondrial DNA haplotype I in two populations. In addition, the trend in the LD between O-ST chromosomal arrangement and haplotype II was general in the total sample. Microsatellite analysis revealed an absence of stochastic processes, like census reduction, upon population differentiation. Only a small amount of the genetic variation is related to geographic distance, while most (97%) is attributable to other factors and in some degree to microhabitat variables (temperature, humidity). The analysis of these factors revealed they effect inversion arrangement frequencies, especially E1+2+9, E-ST and O-ST. Even though this model organism is known for its high mobility and mostly large effective population size, the results presented here reveal that local adaptations can occur even at a small spatial scale. We propose that locally adapted alleles within chromosomal inversions, as well as joint selective pressures acting on mitochondria! and nuclear genomes, are responsible for the observed adaptation to microhabitat conditions.
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