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1.
昆虫翅型分化的表型可塑性机制   总被引:1,自引:0,他引:1       下载免费PDF全文
王小艺  杨忠岐  魏可  唐艳龙 《生态学报》2015,35(12):3988-3999
翅多型现象在昆虫中广泛存在,是昆虫在飞行扩散和繁殖能力之间权衡的一种策略,对种群的环境适应性进化具有重要的意义。目前在植食性昆虫中研究较多,有关寄生蜂的翅型分化鲜见报道。综述了昆虫翅型分化的表型可塑性机制。遗传因素和环境因素均对昆虫翅的发育产生影响,基因型对翅型的决定具有显著作用,外界环境条件,包括温度、光周期、食物质量、自身密度、外源激素等因素对昆虫翅的发育也产生重要的调节作用,从而产生翅的非遗传多型性现象。此外,天敌的寄生或捕食作用可能会诱导某些昆虫的翅型产生隔代表型变化。对昆虫产生翅多型现象的生态学意义及其在生物进化过程中的作用进行了讨论,并探讨了寄生性昆虫翅型分化机制在生物防治上的可能应用途径。功能基因组学和表观遗传学的进一步发展可望为彻底揭示昆虫翅型分化机制提供新的机遇和技术手段。  相似文献   

2.
    
Transgenerational effects are broader than only parental relationships. Despite mounting evidence that multigenerational effects alter phenotypic and life‐history traits, our understanding of how they combine to determine fitness is not well developed because of the added complexity necessary to study them. Here, we derive a quantitative genetic model of adaptation to an extraordinary new environment by an additive genetic component, phenotypic plasticity, maternal and grandmaternal effects. We show how, at equilibrium, negative maternal and negative grandmaternal effects maximize expected population mean fitness. We define negative transgenerational effects as those that have a negative effect on trait expression in the subsequent generation, that is, they slow, or potentially reverse, the expected evolutionary dynamic. When maternal effects are positive, negative grandmaternal effects are preferred. As expected under Mendelian inheritance, the grandmaternal effects have a lower impact on fitness than the maternal effects, but this dual inheritance model predicts a more complex relationship between maternal and grandmaternal effects to constrain phenotypic variance and so maximize expected population mean fitness in the offspring.  相似文献   

3.
    
The effect of extended incubation (delayed hatching) on larval morphology in the terrestrially spawning common galaxias Galaxias maculatus was investigated by inducing larvae to hatch 1 and 2 weeks after the normal 2 week incubation period. After 1 week of extended incubation, larvae were larger (longer in standard length, L(S), and greater in body depth) compared to controls (larvae that experienced normal incubation durations). After 2 weeks of extended incubation, larvae were smaller (shorter in L(S) and smaller in body depth) than larvae that experienced 1 week of extended incubation. Furthermore, eye area increased while yolk-sac size decreased monotonically with increasing incubation duration. These results suggest that larvae experiencing long periods of extended incubation are using somatic tissue to meet their metabolic demands. Larvae that experienced 2 weeks of extended incubation succumbed to starvation sooner than control larvae, but hatching success was not significantly different. Temperature mediated the effect of extended incubation on the morphology of larvae at hatching, most likely, through its effects on developmental rate and efficiency of yolk utilization. This study demonstrates some of the consequences of terrestrial spawning with extended incubation, which will assist in determining why this intriguing behaviour has evolved several times in a diverse range of taxa.  相似文献   

4.
    
1. Maternal and offspring diet effects on life‐history traits of the bird cherry‐oat aphid Rhopalosiphum padi were tested on three wheat varieties. Using nine reciprocal combinations of wheat varieties, the effects of previous experience (maternal diet effect) on the aphid's response to resistant and susceptible varieties (offspring diet effect) were tested. Batis was susceptible, and Xiaoyan22 and Ww2730 were both resistant, but with different mechanisms. 2. Aphids produced the most alatae in the treatments with the most resistant maternal diet variety Xiaoyan22. The fecundity (F) and intrinsic rate of increase (rm) of these alatae were at their greatest in the most resistant offspring diet variety, but these traits were not influenced in the apterae. 3. There were significant interactions in the alatae production and apterae life‐history traits, such as rm, development time, weight gain, and mean relative growth rate, between the maternal and offspring diet varieties. The interactions in apterae responses between varieties, some of which were reciprocal, indicated phenotypic plasticity in these parthenogenetic aphids. 4. Rhopalosiphum padi produced more alatae on the most resistant variety; the alatae would disperse and were more fecund. The growth responses of the apterae showed phenotypic plasticity to the different combinations of maternal and offspring diet varieties. The phenotypic plasticity would allow R. padi to better utilise the variable environments represented by the small wheat plots of different varieties in China.  相似文献   

5.
    
F ST and RST estimates for Arctic charr from six microsatelite markers collected from two neighbouring Scottish lakes, Loch Maree and Loch Stack, confirm the presence of two distinct genetic groupings representing separate populations within each lake. In both lakes, there was also a clear body size dimorphism, with large and small body size forms that segregated according to genetic grouping. There was evidence of only subtle foraging ecology differences between morphs, with the small body size morph in both lakes being more generalist in its foraging in the summer (consuming mostly plankton but also some macrobenthos) than the large body size morph, which specialized on planktonic prey. Trophic morphology (head and mouth shape) did not differ significantly between morphs (although the small sample size for Maree makes this a preliminary finding). Cluster analysis of the microsatelite data and the presence of private alleles showed that morphologically similar forms in different lakes were not genetically similar, as would be expected under a multiple invasion hypothesis. Thus, the data do not support a hypothesis of a dual invasion of both lakes by two common ancestors but instead suggest an independent origin of the two forms in each lake. Thus parallel sympatric divergence as a result of common selection pressures in both lakes is the most parsimonious explanation of the evolutionary origin of these polymorphisms. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 748–757.  相似文献   

6.
    
Maternal effects provide the most common mechanism by which environmental variation in one generation affects the phenotype of individuals in subsequent generations. In egg-laying animals, however, we typically observe that maternal effects can have large influences on early growth (egg size and early development), but these effects gradually disappear and become undetectable by the time progeny mature due to developmental plasticity in progeny. We describe a system in which an environmentally induced reduction in body size is inherited by progeny via a nongenetic maternal effect. The seed beetle, Callosobruchus maculatus, completes development inside a discrete resource package (a seed) selected by its mother. Due to superparasitism in response to low host availability, progeny frequently develop at high densities, resulting in intense larval competition and pupation at a smaller body size. Females reared at higher density (and thus emerging smaller) lay smaller eggs than females reared at lower density. Progeny from these smaller eggs mature at a smaller size than progeny reared from the larger eggs laid by females reared at lower density. Crosses between high and low density lines demonstrated that treatment differences in body size are maternally inherited, confirming that the inheritance of body size variation in part involves an environmentally based maternal effect.  相似文献   

7.
    
Abstract.  1. Variability in life-history traits of the common pond skater Gerris lacustris (L.) (Heteroptera: Gerridae) was investigated on a small geographical scale in Bavaria, Germany (≈ 49 °N). In an area of approximately 3.5 × 3.0 km, voltinism and wing length data of G. lacustris were recorded from 65 ponds located either in an open field or surrounded by forest.
2. Life history differed significantly between populations in the two habitat types. Gerris lacustris showed a bivoltine life-cycle in most of the field ponds with a high proportion of long-winged individuals in the diapause generation and a large increase of the short-winged morph in the midsummer generation. In contrast, almost all populations inhabiting forest ponds were univoltine. Only a few forest populations produced any second generation larvae. The long-winged morph dominated during the whole season in forest ponds.
3. The appearance of first-instar larvae was delayed by 3–4 weeks in forest ponds compared with field ponds. Presumably, low temperatures led to this reduction in the developmental rate of eggs and larvae. Consequently, 'field larvae' of the first generation developed under increasing daylight conditions (triggering direct reproduction and brachyptery) but 'forest larvae' developed under a shortening photoperiod (triggering diapause and macroptery).
4. Offspring raised from 'forest parents' in the laboratory showed the same variability in life history when reared in a cool (16.9 ± 2.4 °C) or warm (23.1 ± 1.8 °C) temperature regime.
5. Given the small spatial scale of the study, it is concluded that the variability in the life history of G. lacustris has a strong phenotypic component.  相似文献   

8.
植物表型受自身基因型、所处环境及其亲体所经历环境的共同影响;其中,亲体环境对子代表型的影响被称为亲体效应。亲体效应不仅可通过有性繁殖产生的种子传递给后代(即有性亲体效应),也可以通过克隆生长等无性繁殖产生的分株传递给后代(即克隆亲体效应)。亲体效应对植物种群,特别是对有性繁殖受限、缺乏遗传变异的克隆植物种群的长期进化可能发挥着极其重要的作用,因此,对亲体效应研究进展的梳理非常必要。对克隆亲体效应和有性亲体效应的内涵进行了阐释,并论述了克隆和有性亲体效应对子代表型、适合度、种内/种间竞争能力以及种群/群落结构和功能的潜在影响;阐述了亲体效应的潜在调控机制,包括供给机制、代谢物质调控机制、表观遗传机制等;论述了克隆亲体效应在克隆植物适应进化中的作用。未来可以就克隆亲体效应的遗传稳定性及其对克隆生活史性状变异的贡献程度,以及克隆和有性亲体效应引起的表型多样性对种内/种间关系、种群/群落多样性及生态系统结构、功能和稳定性的影响开展深入研究。  相似文献   

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Existing insight suggests that maternal effects have a substantial impact on evolution, yet these predictions assume that maternal effects themselves are evolutionarily constant. Hence, it is poorly understood how natural selection shapes maternal effects in different ecological circumstances. To overcome this, the current study derives an evolutionary model of maternal effects in a quantitative genetics context. In constant environments, we show that maternal effects evolve to slight negative values that result in a reduction of the phenotypic variance (canalization). By contrast, in populations experiencing abrupt change, maternal effects transiently evolve to positive values for many generations, facilitating the transmission of beneficial maternal phenotypes to offspring. In periodically fluctuating environments, maternal effects evolve according to the autocorrelation between maternal and offspring environments, favoring positive maternal effects when change is slow, and negative maternal effects when change is rapid. Generally, the strongest maternal effects occur for traits that experience very strong selection and for which plasticity is severely constrained. By contrast, for traits experiencing weak selection, phenotypic plasticity enhances the evolutionary scope of maternal effects, although maternal effects attain much smaller values throughout. As weak selection is common, finding substantial maternal influences on offspring phenotypes may be more challenging than anticipated.  相似文献   

11.
    
1. Aphid natural enemies include not only predators and parasitoids but also pathogens, of which fungi are the most studied for biological control. While wing formation in aphids is induced by abiotic conditions, it is also affected by biotic interactions with their arthropod natural enemies. Wing induction via interactions with arthropod natural enemies is mediated by the increase in their physical contact when alarmed (pseudo‐crowding). Pathogenic fungi do not trigger this alarm behaviour in aphids and, therefore, no pseudo‐crowding occurs. 2. We hypothesise that, while pathogenic fungi will stimulate maternally induced wing formation, the mechanism is different and is influenced by pathogen specificity. We tested this hypothesis using two entomopathogenic fungi, Pandora neoaphidis and Beauveria bassiana, an aphid specialist and a generalist respectively, on the pea aphid, Acyrthosiphon pisum Harris. 3. We first demonstrate that pea aphids infected with either pathogen and maintained in groups on broad bean plants produced a higher proportion of winged morphs than uninfected control aphids. We then show that, when maintained in isolation, aphids infected with either pathogen also produced higher proportions of winged offspring than control aphids. There was no difference between P. neoaphidis and B. bassiana in their effects on wing induction in either experiment. 4. Unlike the effect of predators and parasitoids on pea aphid wing induction, the effect of pathogens is independent of physical contact with other aphids, suggesting that physiological cues induce wing formation in infected aphids. It is possible that aphids benefit from wing induction by escaping infected patches whilst pathogens may benefit through dispersion. Possible mechanisms of wing induction are discussed.  相似文献   

12.
Abstract. The Photoperiodic of winged females (alatae) in the black bean aphid, Aphis fabae Scop. (Homopetera: Aphididae), is investigated in detail with emphasis on the interaction of the maternal and embryonic/young larval photoperiodic clocks. Previous work had shown that in uncrowded conditions the induction of gynoparae (winged females that produce sexual females) requires both prenatal and postnatal exposure to long-night (12 h) Photoperidic cycles: present results show that sole postantal exposure to long nights of any lenght does not induce wing formation in early-born aphids.
When aphids were exposed to experimental light-dark cycles postanatally only, their daughters developed as alate in long nights and as apterae in short nights: the critical night lenght (CNL) was 11:1 h. Additional prenatal exposure to experimental regimes resulted in a significantly shorter CNL (10.6 h). This difference could be accounted for by the fact that more experimental light-dark cycles were experienced in the latter case.
Apterous aphids transferred from LD 16:8 h to LD 12:12 h as either third-or fourth-stadium larvae, or young adults, switched for aptera-production to alata-production. The transition form aptera- to alata-production was rather abrupt in third-stadium transfers but more gradual when transfers occurred as fourth-stadium larvae and adults. Moreover, s the number of days required for 50% of the aphids to become alata-producers increased from 7–8 in third-stadium transfers, to 9–10 and 11–12 in the later transfers.  相似文献   

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14.
    
Plastic responses to temperature during embryonic development are common in ectotherms, but their evolutionary relevance is poorly understood. Using a combination of field and laboratory approaches, we demonstrate altitudinal divergence in the strength of effects of maternal thermal opportunity on offspring birth date and body mass in a live-bearing lizard (Niveoscincus ocellatus). Poor thermal opportunity decreased birth weight at low altitudes where selection on body mass was negligible. In contrast, there was no effect of maternal thermal opportunity on body mass at high altitudes where natural selection favored heavy offspring. The weaker effect of poor maternal thermal opportunity on offspring development at high altitude was accompanied by a more active thermoregulation and higher body temperature in highland females. This may suggest that passive effects of temperature on embryonic development have resulted in evolution of adaptive behavioral compensation for poor thermal opportunity at high altitudes, but that direct effects of maternal thermal environment are maintained at low altitudes because they are not selected against. More generally, we suggest that phenotypic effects of maternal thermal opportunity or incubation temperature in reptiles will most commonly reflect weak selection for canalization or selection on maternal strategies rather than adaptive plasticity to match postnatal environments.  相似文献   

15.
    
An important step in diagnosing local adaptation is the demonstration that phenotypic variation among populations is at least in part genetically based. To do this, many methods experimentally minimize the environmental effect on the phenotype to elucidate the genetic effect. Minimizing the environmental effect often includes reducing possible environmental maternal effects. However, maternal effects can be an important factor in patterns of local adaptation as well as adaptive plasticity. Here, we report the results of an experiment with males from two populations of the poeciliid fish, Heterandria formosa, designed to examine the relative influence of environmental maternal effects and environmental effects experienced during growth and development on body morphology, and, in addition, whether the balance among those effects is unique to each population. We used a factorial design that varied thermal environment and water chemistry experienced by mothers and thermal environment and water chemistry experienced by offspring. We found substantial differences between the two populations in their maternal and offspring norms of reaction of male body morphology to differences in thermal environment and water chemistry. We also found that the balance between maternal effects and postparturition environmental effects differed from one thermal regime to another and among traits. These results indicate that environmental maternal effects can be decidedly population‐specific and, as a result, might either contribute to the appearance of or blur evidence for local adaptation. These results also suggest that local adaptation might also occur through the evolution of maternal norms of reaction to important, and varying, environmental factors.  相似文献   

16.
    
Relatively little is known about whether and how nongenetic inheritance interacts with selection to impact the evolution of phenotypic plasticity. Here, we empirically evaluated how stabilizing selection and a common form of nongenetic inheritance—maternal environmental effects—jointly influence the evolution of phenotypic plasticity in natural populations of spadefoot toads. We compared populations that previous fieldwork has shown to have evolved conspicuous plasticity in resource‐use phenotypes (“resource polyphenism”) with those that, owing to stabilizing selection favouring a narrower range of such phenotypes, appear to have lost this plasticity. We show that: (a) this apparent loss of plasticity in nature reflects a condition‐dependent maternal effect and not a genetic loss of plasticity, that is “genetic assimilation,” and (b) this plasticity is not costly. By shielding noncostly plasticity from selection, nongenetic inheritance generally, and maternal effects specifically, can preclude genetic assimilation from occurring and consequently impede adaptive (genetic) evolution.  相似文献   

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The evolution of adaptive phenotypic plasticity relies on the presence of cues that enable organisms to adjust their phenotype to match local conditions. Although mostly studied with respect to nonsocial cues, it is also possible that parents transmit information about the environment to their offspring. Such ‘anticipatory parental effects’ or ‘adaptive transgenerational plasticity’ can have important consequences for the dynamics and adaptive potential of populations in heterogeneous environments. Yet, it remains unknown how widespread this form of plasticity is. Using a meta‐analysis of experimental studies with a fully factorial design, we show that there is only weak evidence for higher offspring performance when parental and offspring environments are matched compared with when they are mismatched. Estimates of heterogeneity among studies suggest that effects, when they occur, are subtle. Study features, environmental context, life stage and trait categories all failed to explain significant amounts of variation in effect sizes. We discuss theoretical and methodological reasons for the limited evidence for anticipatory parental effects and suggest ways to improve our understanding of the prevalence of this form of plasticity in nature.  相似文献   

19.
    
Since the classic work of E.B. Ford, explanations for eyespot variation in the Meadow Brown butterfly have focused on the role of genetic polymorphism. The potential role of thermal plasticity in this classic example of natural selection has therefore been overlooked. Here, we use large daily field collections of butterflies from three sites, over multiple years, to examine whether field temperature is correlated with eyespot variation, using the same presence/absence scoring as Ford. We show that higher developmental temperature in the field leads to the disappearance of the spots visible while the butterfly is at rest, explaining the historical observation that hindwing spotting declines across the season. Strikingly, females developing at 11°C have a median of six spots and those developing at 15°C only have three. In contrast, the large forewing eyespot is always present and scales with forewing length. Furthermore, in contrast to the smaller spots, the size of the large forewing spot is best explained by calendar date (days since 1st March) rather than the temperature at pupation. As this large forewing spot is involved in startling predators and/or sexual selection, its constant presence is therefore likely required for defence, whereas the disappearance of the smaller spots over the season may help with female crypsis. We model annual total spot variation with phenological data from the UK and derive predictions as to how spot patterns will continue to change, predicting that female spotting will decrease year on year as our climate warms.  相似文献   

20.
Reaction norms to growth temperature of two size-related traits, wing and thorax length, were compared in tropical (West Indies) and temperate (France) populations of the two sibling species, Drosophila melanogaster and D. simulans. A major body size difference was found in D. melanogaster, with much smaller Caribbean flies, while D. simulans exhibited little size variation between geographical populations. The concave norms of reaction were adjusted to second- or third-degree polynomials, and characteristic points calculated i.e. maximum value (MV) and temperature of maximum value (TMV). TMVs were confirmed to be higher for thorax than for wing length, higher in D. melanogaster than in D. simulans, and higher in females than in males. For both traits Caribbean populations exhibited higher TMVs in the two species, strongly suggesting an adaptive shift of the reaction norms toward higher temperature in warm-adapted populations. The wing/thorax ratio was also analysed, and found to be significantly lower in tropical populations of both species. This ratio, which is related to wing loading and flight capacity, might evolve independently of body weight itself.  相似文献   

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