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Electrophoretic variation at three enzyme loci‐alcohol dehydrogenase (Adh), glycerophosphate dehydrogenase (Gpdh), triosephosphate isomerase (Tpi)‐ is compared in Australian Drosophila melanogaster populations at three levels of spatial... more
Electrophoretic variation at three enzyme loci‐alcohol dehydrogenase (Adh), glycerophosphate dehydrogenase (Gpdh), triosephosphate isomerase (Tpi)‐ is compared in Australian Drosophila melanogaster populations at three levels of spatial heterogeneity; among breeding sites, within populations, and between populations at the geographic level. Heterogeneity at the breeding site level greatly exceeds that among adults within populations, indicating greater intermixing at the mobile adult stage than at the developmentally immature and less migratory larval stage. Heterogeneity at the microspatial level is large relative to the geographic level at two of these loci.Spatial patterns of variation in ecological phenotypes are also considered. It is argued that electrophoretic variants may contribute little to an understanding of this quantitative variation, and that a more useful approach in ecological genetics is to consider ecological phenotypes as primary data.
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wft-ssr-genepop-input-dat
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Comparative analyses of ectotherm susceptibility to climate change often focus on thermal extremes, yet responses to aridity may be equally important. Here we focus on plasticity in desiccation resistance, a key trait shaping... more
Comparative analyses of ectotherm susceptibility to climate change often focus on thermal extremes, yet responses to aridity may be equally important. Here we focus on plasticity in desiccation resistance, a key trait shaping distributions of <i>Drosophila</i> species and other small ectotherms. We examined the extent to which 32 <i>Drosophila</i> species, varying in their distribution, could increase their desiccation resistance via phenotypic plasticity involving hardening, linking these responses to environment, phylogeny and basal resistance. We found no evidence to support the seasonality hypothesis; species with higher hardening plasticity did not occupy environments with higher and more seasonal precipitation. As basal resistance increased, the capacity of species to respond via phenotypic plasticity decreased, suggesting plastic responses involving hardening may be constrained by basal resistance. Trade-offs between basal desiccation resistance and plasticity were not universal across the phylogeny and tended to occur within specific clades. Phylogeny, environment and trade-offs all helped to explain variation in plasticity for desiccation resistance but in complex ways. These findings suggest some species have the ability to counter dry periods through plastic responses, whereas others do not; and this ability will depend to some extent on a species' placement within a phylogeny, along with its basal level of resistance.
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wft-ssr-geneland-input-dat
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Wolbachia bacteria are being widely released for suppression of dengue transmitted by Aedes mosquitoes. Walker, Quek, Jeffries and colleagues present robust evidence for natural Wolbachia infections in malaria-vectoring Anopheles... more
Wolbachia bacteria are being widely released for suppression of dengue transmitted by Aedes mosquitoes. Walker, Quek, Jeffries and colleagues present robust evidence for natural Wolbachia infections in malaria-vectoring Anopheles mosquitoes, paving the way for new Wolbachia-based interventions.
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Spodoptera frugiperda has been reported in China since the beginning of 2019, threatening maize production and raising questions about interactions with indigenous pests on maize. Spodoptera frugiperda is in the same feeding guild as the... more
Spodoptera frugiperda has been reported in China since the beginning of 2019, threatening maize production and raising questions about interactions with indigenous pests on maize. Spodoptera frugiperda is in the same feeding guild as the indigenous species Ostrinia furnacalis , with both pests attacking maize plant tissues such as whorls and tassels. In this study, the interaction of these species was assessed under laboratory and field conditions by examining the survival and predation rate of larvae in maize whorls and tassels. Intraspecific and interspecific interactions of larvae were assessed to characterize movements in arenas in the presence and absence of food. When S. frugiperda and O. furnacalis were present at an equal ratio, S. frugiperda prevailed over O. furnacalis with a high survival rate (over 90%) and predation rate of O. furnacalis (over 40%) under most scenarios in both laboratory and field conditions. When both species occurred at different ratios in the field, S. frugiperda had on average almost 16 times the number of survivors as O. furnacalis on whorls, and 8.3 times the number on tassels, highlighting a substantial advantage in these environments. Spodoptera frugiperda larvae undertook a low frequency of lethal attacks (strikes) and showed a higher incidence of defensive movements compared to O. furnacalis . A field survey showed that S. frugiperda larvae can colonize vegetative plant stages in maize, but it remains to be seen if competitive interactions can be linked to population dynamics of both species though they are expected to favor S. frugiperda .
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We have started to test the effects of environmental extremes on the expression of genetic variation for traits likely to be under selection in natural populations. We have shown that field heritability may be high for stress response... more
We have started to test the effects of environmental extremes on the expression of genetic variation for traits likely to be under selection in natural populations. We have shown that field heritability may be high for stress response traits in contrast to morphological traits, which tend to show lower levels of heritable variation in nature compared with the laboratory. Selection for increased stress resistance can lead to a number of other evolutionary changes, and these may underlie trade-offs between favourable and stressful environments. Temperature extremes can have a marked influence on the heritability of life history traits. Heritabilities for fecundity can be high when parental flies are reared at low temperatures and under field conditions. The expression of genetic variation for development time is somewhat more complex when temperature extremes are considered. Populations at species margins may be ideal for studying the effects of environmental stress on evolution.
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The Scaptodrosophila genus represents a large group of drosophilids with a worldwide distribution and a predominance of species in Australia, but there is little information on the presence and impacts of Wolbachia endosymbionts in this... more
The Scaptodrosophila genus represents a large group of drosophilids with a worldwide distribution and a predominance of species in Australia, but there is little information on the presence and impacts of Wolbachia endosymbionts in this group. Here we describe the first Wolbachia infection from this group, wClay isolated from Scaptodrosophila claytoni (van Klinken), a species from the east coast of Australia. The infection is polymorphic in natural populations, occurring at a frequency of around 6%–10%. wClay causes male killing, producing female‐biased lines; most lines showed 100% male killing, though in 1 line it was &lt;80%. The lines need to be maintained through the introduction of males unless the infection is removed by tetracycline treatment. wClay is transmitted at a high fidelity (98.6%) through the maternal lineage and has been stable in 2 laboratory lines across 24 generations, suggesting it is likely to persist in populations. The infection has not been previously described but is closely related to the male‐killing Wolbachia recently described from Drosophila pandora based on multilocus sequence typing and the wsp gene. Male‐killing Wolbachia are likely to be common in drosophilids but remain difficult to detect because the infections can often be at a low frequency.
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BACKGROUNDThe diamondback moth (DBM) Plutella xylostella has developed resistance to almost all insecticides used to control it. Populations of DBM in temperate regions mainly migrate from annual breeding areas. However, the distribution... more
BACKGROUNDThe diamondback moth (DBM) Plutella xylostella has developed resistance to almost all insecticides used to control it. Populations of DBM in temperate regions mainly migrate from annual breeding areas. However, the distribution pattern of insecticide resistance of DBM within the context of long‐distance migration remains unclear.RESULTSIn this study, we examined the frequency of 14 resistance mutations for 52 populations of DBM collected in 2010, 2011, 2017 and 2018 across China using a high‐throughput KASP genotyping method. Mutations L1041F and T929I conferring pyrethroid resistance, and mutations G4946E and E1338D conferring chlorantraniliprole resistance were near fixation in most populations, whereas resistant alleles of F1020S, M918I, A309V and F1845Y were uncommon or absent in most populations. Resistance allele frequencies were relatively stable among different years, although the frequency of two mutations decreased. Principal component analysis based on resistant allele frequencies separated a southern population as an outlier, whereas the immigrants clustered with other populations, congruent with the migration pattern of northern immigrants coming from the Sichuan area of southwestern China. Most resistant mutations deviated from Hardy–Weinberg equilibrium due to a lower than expected frequency of heterozygotes. The deviation index of heterozygosity for resistant alleles was significantly higher than the index obtained from single nucleotide polymorphisms across the genome. These findings suggest heterogeneous selection pressures on resistant mutations.CONCLUSIONOur results provide a picture of resistant mutation patterns in DBM shaped by insecticide usage and migration of this pest, and highlight the widespread distribution of resistance alleles in DBM. © 2022 Society of Chemical Industry.
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Genetic variation among individuals serves as the foundation for processes by which species and populations adapt to local conditions and evolve (Hartl and Clark 1997). Ample genetic variation is required for adaptation to stressful and... more
Genetic variation among individuals serves as the foundation for processes by which species and populations adapt to local conditions and evolve (Hartl and Clark 1997). Ample genetic variation is required for adaptation to stressful and changing environments, including pesticide applications and chemical exposures. Genetic variation can be used to describe current and historical population attributes such as size and structure. But the inclusion of genetic methods and processes in population ecology has been slow (e.g., Jackson et al. 2002), and mechanisms for incorporating genetics into population dynamics are relatively unexplored (but see Chapters 8 and 9). Thus, despite its fundamental importance, genetic variation has rarely been considered quantitatively in predictions of population persistence (e.g., Beissinger and McCullough 2002), and is almost never considered in ecological risk assessments (ERAs). However, genetic information is becoming increasingly accessible and the relevance of genetic changes better understood as more gene functions become known (e.g., Collins et al. 2003; Jackson et al. 2002). More specific to the needs of ERAs, these advances are contributing to improved understanding of relationships among stress, changes in genetic variation, and population persistence.
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Under exposure to harmful environmental stresses, organisms exhibit a general stress response involving upregulation of the expression of heat shock proteins (HSPs) which is thought to be adaptive. Small heat shock proteins (sHSPs) are... more
Under exposure to harmful environmental stresses, organisms exhibit a general stress response involving upregulation of the expression of heat shock proteins (HSPs) which is thought to be adaptive. Small heat shock proteins (sHSPs) are key components of this response, although shsp genes may have other essential roles in development. However, the upregulation of expression of a suite of genes under stress may not necessarily be evidence of an adaptive response to stress that involves those genes. To explore this issue, we used the CRISPR/Cas9 system to investigate pleiotropic effects of the hsp23 gene in Drosophila melanogaster. Transgenic flies carrying a pCFD5 plasmid containing sgRNAs were created to generate a complete knock out of the hsp23 gene. The transgenic line lacking hsp23 showed an increased hatch rate and no major fitness costs under an intermediate temperature used for culturing the flies. In addition, hsp23 knockout affected tolerance to hot and cold temperature extremes but in opposing directions; knockout flies had reduced tolerance to cold, but increased tolerance to heat. Despite this, hsp23 expression (in wild type flies) was increased under both hot and cold conditions. The hsp23 gene was required for heat hardening at the pupal stage, but not at the 1st-instar larval stage, even though the gene was upregulated in wild type controls at that life stage. The phenotypic effects of hsp23 were not compensated for by expression changes in other shsps. Our study shows that the fitness consequences of an hsp gene knockout depends on environmental conditions, with potential fitness benefits of gene loss even under conditions when the gene is normally upregulated.
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Although climate warming can increase both mean temperature and its variability, it is often the effects of climate warming on short periods of extreme temperatures that are expected to have particularly large physiological and ecological... more
Although climate warming can increase both mean temperature and its variability, it is often the effects of climate warming on short periods of extreme temperatures that are expected to have particularly large physiological and ecological consequences. Understanding the vulnerability of organisms at various latitudes to climate extremes is thus critical for understanding warming effects on regional biodiversity conservation and ecosystem management. While previous studies have shown that thermal responses depend on temperature regimes that organisms have previously experienced, this issue has not been considered much when comparing the effects of temperature extremes at different latitudes. To fill this gap, here we manipulated different combinations of amplitude and duration of daily high temperature extremes to simulate conditions at different latitudes. We tested the effects of those regimes on life-history traits and fitness of a globally-distributed aphid species, Rhopalosiphum padi. We compared our results with previous studies to better understand the extent to which these regimes affect conclusions based on comparisons under different mean temperatures. As a consequence of asymmetrical thermal performance curves, we hypothesized that the temperature regimes with higher daily maximum temperatures at higher latitudes would cause strong negative effects. Our results showed that these regimes with thermal extremes caused substantial decreases in life-history traits and fitness relative to the predictions from different mean temperatures. Specifically, the regime with higher daily maximum temperature reflecting a higher mid-latitude location had larger impacts on development, reproduction and population fitness than the regime representing a lower mid-latitude location. These findings have implications for understanding the vulnerability of organisms across latitudes to increasingly frequent extreme heat events under ongoing climate warming.
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Research Interests: Biology, Medicine, Spiroplasma, Wolbachia, Spider, and 2 moreMite and Spider mite(Mite and Spider mite)
(Mite and Spider mite)
Parent‐offspring comparisons were used to investigate the effects of temperature extremes on genetic variances for two life history traits and one morphological trait in Drosophila melanogaster. We considered three temperatures (14 °C, 25... more
Parent‐offspring comparisons were used to investigate the effects of temperature extremes on genetic variances for two life history traits and one morphological trait in Drosophila melanogaster. We considered three temperatures (14 °C, 25 °C and 28 °C) for culturing and testing flies, and considered heritabilities, coefficients of additive variation (CVA) and evolvabilities (IA) for fecundity, development time and wing length. For fecundity, heritabilities and evolvabilities were higher when parents were exposed to 14 °C compared to 28 °C. Parent‐offspring comparisons suggested that genetic correlations among environments were close to 1, although lower correlations were obtained in comparisons of family means. Parent‐offspring correlations across environments seemed to depend on parental temperature. For development time, heritabilities and evolvabilities were low at 14 °C compared to 28 °C. However, parent‐offspring correlations were relatively high when the progeny of parents tested at 14 °C were raised at the opposite extreme, suggesting that genetic variation can be enhanced when parents and offspring experience different conditions. CVAs and IAs for development time were lower than for fecundity, even when heritability estimates were similar in magnitude. Genetic variation for wing length was generally not affected by the temperature extremes, and genetic correlations across the extremes estimated from the parent‐offspring comparison were close to 1. There was no evidence for tradeoffs between traits; rapid development time was associated with high fecundity at both the phenotypic and genetic levels. The findings highlight inherent difficulties of estimating genetic parameters from parent‐offspring comparisons when two generations experience different environmental extremes and also show how parent‐offspring comparisons can lead to unexpected findings about the expression of genetic variation.
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Changing climatic conditions have both direct and indirect influences on abiotic and biotic processes and represent a potent source of novel selection pressures for adaptive evolution. In addition, climate change can impact evolution by... more
Changing climatic conditions have both direct and indirect influences on abiotic and biotic processes and represent a potent source of novel selection pressures for adaptive evolution. In addition, climate change can impact evolution by altering patterns of hybridization, changing population size, and altering patterns of gene flow in landscapes. Given that scientific evidence for rapid evolutionary adaptation to spatial variation in abiotic and biotic environmental conditions—analogous to that seen in changes brought by climate change—is ubiquitous, ongoing climate change is expected to have large and widespread evolutionary impacts on wild populations. However, phenotypic plasticity, migration, and various kinds of genetic and ecological constraints can preclude organisms from evolving much in response to climate change, and generalizations about the rate and magnitude of expected responses are difficult to make for a number of reasons. First, the study of microevolutionary responses to climate change is a young field of investigation. While interest in evolutionary impacts of climate change goes back to early macroevolutionary (paleontological) studies focused on prehistoric climate changes, microevolutionary studies started only in the late 1980s. The discipline gained real momentum in the 2000s after the concept of climate change became of interest to the general public and funding organizations. As such, no general conclusions have yet emerged. Second, the complexity of biotic changes triggered by novel climatic conditions renders predictions about patterns and strength of natural selection difficult. Third, predictions are complicated also because the expression of genetic variability in traits of ecological importance varies with environmental conditions, affecting expected responses to climate-mediated selection. There are now several examples where organisms have evolved in response to selection pressures associated with climate change, including changes in the timing of life history events and in the ability to tolerate abiotic and biotic stresses arising from climate change. However, there are also many examples where expected selection responses have not been detected. This may be partly explainable by methodological difficulties involved with detecting genetic changes, but also by various processes constraining evolution. There are concerns that the rates of environmental changes are too fast to allow many, especially large and long-lived, organisms to maintain adaptedness. Theoretical studies suggest that maximal sustainable rates of evolutionary change are on the order of 0.1 haldanes (i.e., phenotypic standard deviations per generation) or less, whereas the rates expected under current climate change projections will often require faster adaptation. Hence, widespread maladaptation and extinctions are expected. These concerns are compounded by the expectation that the amount of genetic variation harbored by populations and available for selection will be reduced by habitat destruction and fragmentation caused by human activities, although in some cases this may be countered by hybridization. Rates of adaptation will also depend on patterns of gene flow and the steepness of climatic gradients. Theoretical studies also suggest that phenotypic plasticity (i.e., nongenetic phenotypic changes) can affect evolutionary genetic changes, but relevant empirical evidence is still scarce. While all of these factors point to a high level of uncertainty around evolutionary changes, it is nevertheless important to consider evolutionary resilience in enhancing the ability of organisms to adapt to climate change.
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Delaying emergence of Trichogramma spp. is critical for commercial production. Here, diapause induction was considered for three species (Trichogramma nr. brassicae Bezdenko, Trichogramma carverae Oatman... more
Delaying emergence of Trichogramma spp. is critical for commercial production. Here, diapause induction was considered for three species (Trichogramma nr. brassicae Bezdenko, Trichogramma carverae Oatman &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Pinto, and Trichogramma funiculatum Carver), and the effect of storage temperature (4 degrees C, 8 degrees C, and 10 degrees C) and time (1-8 wk) was investigated for T. carverae. For all species, percentage of emergence was lowered after an initial diapause induction period (28 d at 14 degrees C and a photoperiod of 8:16 [L:D] h) and lowered further after 1-mo storage at 3 degrees C and a photoperiod of 0:24 (L:D) h. No wasps emerged after 2 mo of storage, suggesting that true diapause was not induced. The effect of 1-8-wk storage on wasp quality was investigated for T. carverae both in the laboratory and the field. Initial fieldwork suggested that this species could be successfully stored at 10 degrees C under continuous light (after 5-d development at 25 degrees C and a photoperiod of 16:8 [L:D] h) without reducing the ability of wasps to parasitize eggs in the field. In a second experiment, storage temperatures lower than 10 degrees C and storage times 3 wk or longer had a negative impact on emergence and longevity, and effects were not additive. Negative effects may partly reflect size changes, because size decreased in response to storage time, and there was an interaction between time and temperature effects on size. Storage time was the major factor influencing fecundity and field success; both fitness measures were reduced after storage of 3 wk or longer. T. carverae can therefore be successfully stored for up to 2 wk without detrimental effects, and 10 degrees C is the preferred storage temperature. T. carverae seems to survive unfavorable temperature conditions by entering a state of quiescence.
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Parent‐offspring comparisons were used to investigate the effects of temperature extremes on genetic variances for two life history traits and one morphological trait in Drosophila melanogaster. We considered three temperatures (14 °C, 25... more
Parent‐offspring comparisons were used to investigate the effects of temperature extremes on genetic variances for two life history traits and one morphological trait in Drosophila melanogaster. We considered three temperatures (14 °C, 25 °C and 28 °C) for culturing and testing flies, and considered heritabilities, coefficients of additive variation (CVA) and evolvabilities (IA) for fecundity, development time and wing length. For fecundity, heritabilities and evolvabilities were higher when parents were exposed to 14 °C compared to 28 °C. Parent‐offspring comparisons suggested that genetic correlations among environments were close to 1, although lower correlations were obtained in comparisons of family means. Parent‐offspring correlations across environments seemed to depend on parental temperature. For development time, heritabilities and evolvabilities were low at 14 °C compared to 28 °C. However, parent‐offspring correlations were relatively high when the progeny of parents tested at 14 °C were raised at the opposite extreme, suggesting that genetic variation can be enhanced when parents and offspring experience different conditions. CVAs and IAs for development time were lower than for fecundity, even when heritability estimates were similar in magnitude. Genetic variation for wing length was generally not affected by the temperature extremes, and genetic correlations across the extremes estimated from the parent‐offspring comparison were close to 1. There was no evidence for tradeoffs between traits; rapid development time was associated with high fecundity at both the phenotypic and genetic levels. The findings highlight inherent difficulties of estimating genetic parameters from parent‐offspring comparisons when two generations experience different environmental extremes and also show how parent‐offspring comparisons can lead to unexpected findings about the expression of genetic variation.
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Trichogramma nr. brassicae is a common egg parasitoid of Helicoverpa species in Australian processing tomatoes, but its effectiveness can be severely curtailed by insecticide applications. To identify insecticides that are potentially... more
Trichogramma nr. brassicae is a common egg parasitoid of Helicoverpa species in Australian processing tomatoes, but its effectiveness can be severely curtailed by insecticide applications. To identify insecticides that are potentially compatible with this species, the effects of seven insecticides, including newly introduced compounds and a surfactant, were screened in laboratory and glasshouse assays for their toxicity to the wasps. Assays involved direct applications on adults, residual effects on adults, and applications on life stages still inside the host. Methoxyfenozide and indoxacarb were not toxic to Trichogramma in any assay when applied at field rates. Naled and chlorfenapyr caused 100% mortality when directly applied to adults, and 95% mortality when adults were exposed to residues of these chemicals within 24 h of application. The effects of naled residues were short lived (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;48 h). Naled and chlorfenapyr were also toxic when applied to Trichogramma developing inside host eggs, reducing emergence of adults by &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;25%. Imidacloprid, emamectin, and tau-fluvalinate were toxic in some experiments; they caused &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;97% mortality in adults 1 h after direct application and in residue assays they caused 23-64% mortality during the first 24 h. In field trials, methoxyfenozide had no harmful effects on emergence from sprayed parasitized eggs, whereas indoxacarb had a small impact (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;8%) on emergence. Methoxyfenozide and indoxacarb are potentially suitable for inclusion in integrated pest management strategies for management of Helicoverpa because they do not influence adult survival or development of immature stages, whereas other chemicals need to be treated cautiously.
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To determine whether and how laboratory and natural selection act on the hsp70 (70-Kd heat-shock protein) genes of Drosophila melanogaster, we examined hsp70 allele frequencies in two sets of populations. First, five populations reared at... more
To determine whether and how laboratory and natural selection act on the hsp70 (70-Kd heat-shock protein) genes of Drosophila melanogaster, we examined hsp70 allele frequencies in two sets of populations. First, five populations reared at different temperatures for more than 20 years differentially fixed both a large insertion/deletion (indel) polymorphism at the 87A7 hsp70 cluster (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;56H8&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;/&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;122&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;) and a single nucleotide polymorphism at the 87C1 hsp70 cluster. In both cases, the 18 degrees C and 25 degrees C populations fixed one allele and the 28 degrees C populations the other, consistent with previously described evolved differences among these populations in Hsp70 expression and thermotolerance. Second, we examined 56H8 and 122 frequencies in a set of 11 populations founded from flies collected along a latitudinal transect of eastern Australia. The 56H8 allele frequencies are positively associated with latitude, consistent with maintenance of the 56H8/122 polymorphism by natural selection. Thermal extremes and average values are negatively correlated with latitude. These results suggest that natural selection imposed by temperature and thermal variability may affect hsp70 allele frequencies.
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Correlated responses to artificial selection for stress tolerance can provide insight into underlying genetic variation and the physiological basis of stress resistance. Lines of Drosophila melanogaster held in the absence of food or with... more
Correlated responses to artificial selection for stress tolerance can provide insight into underlying genetic variation and the physiological basis of stress resistance. Lines of Drosophila melanogaster held in the absence of food or with an unsuitable resource, specifically decomposing lemon, responded to selection by becoming starvation resistant. The lemon‐selected lines also adapted by evolving a resource‐based induction response. Compared to control lines, the selected lines tended to store more lipid, develop slower and have a larger body size. Additional responses included resistance to desiccation and acetone fumes, suggesting multiple stress resistance is a correlated result of selection for starvation resistance. The specific metabolic rate was lower in the starvation selected lines and enzyme activities changed in response to selection. In particular, enzyme activities indirectly associated with lipid biogenesis increased in both types of selected lines. The correlated responses to the two selection regimes were sufficiently consistent to indicate a common basis for starvation resistance. Specific responses to starvation selection appeared to oppose the short‐term phenotypic responses to starvation. Thus, a common response to stress selection may be to ameliorate the immediate physiological impact of the stress factor.