Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Proc Biol Sci ; 291(2028): 20240533, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39109969

RESUMO

Butterflies, like many insects, use gustatory and olfactory cues innately to assess the suitability of an oviposition site and are able to associate colours and leaf shapes with an oviposition reward. Studies on other insects have demonstrated that the quality of the reward is a crucial factor in forming associative memory. We set out to investigate whether the large cabbage white Pieris brassicae (Linnaeus) has the ability to associate an oviposition experience with a neutral olfactory cue. In addition, we tested whether the strength of this association is dependent on the gustatory response to the glucosinolate sinigrin, which is a known oviposition stimulus for P. brassicae. Female butterflies were able to associate a neutral odour with an oviposition experience after a single oviposition experience, both in a greenhouse and in a semi-natural outdoor setting. Moreover, butterflies performed best when trained with concentrations of sinigrin that showed the strongest response by specific gustatory neurons on the forelegs. Our study provides novel insight into the role of both gustatory and olfactory cues during oviposition learning in lepidopterans and contributes to a better understanding of how these insects might be able to adapt to a rapidly changing environment.


Assuntos
Borboletas , Sinais (Psicologia) , Aprendizagem , Oviposição , Animais , Borboletas/fisiologia , Feminino , Glucosinolatos/metabolismo , Olfato , Odorantes/análise
2.
J Anim Ecol ; 90(7): 1635-1646, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33724445

RESUMO

Dynamic conditions in nature have led to the evolution of behavioural traits that allow animals to use information on local circumstances and adjust their behaviour accordingly, for example through learning. Although learning can improve foraging efficiency, the learned information can become unreliable as the environment continues to change. This could lead to potential fitness costs when memories holding such unreliable information persist. Indeed, persistent unreliable memory was found to reduce the foraging efficiency of the parasitoid Cotesia glomerata under laboratory conditions. Here, we evaluated the effect of such persistent unreliable memory on the foraging behaviour of C. glomerata in the field. This is a critical step in studies of foraging theory, since animal behaviour evolved under the complex conditions present in nature. Existing methods provide little detail on how parasitoids interact with their environment in the field, therefore we developed a novel multi-camera system that allowed us to trace parasitoid foraging behaviour in detail. With this multi-camera system, we studied how persistent unreliable memory affected the foraging behaviour of C. glomerata when these memories led parasitoids to plants infested with non-host caterpillars in a semi-field set-up. Our results demonstrate that persistent unreliable memory can lead to maladaptive foraging behaviour in C. glomerata under field conditions and increased the likelihood of oviposition in the non-host caterpillar Mamestra brassica. Furthermore, these time- and egg-related costs can be context dependent, since they rely on the plant species used. These results provide us with new insight on how animals use previously obtained information in naturally complex and dynamic foraging situations and confirm that costs and benefits of learning depend on the environment animals forage in. Although behavioural studies of small animals in natural habitats remain challenging, novel methods such as our multi-camera system contribute to understanding the nuances of animal foraging behaviour.


Assuntos
Mariposas , Vespas , Animais , Feminino , Interações Hospedeiro-Parasita , Larva , Oviposição
3.
Cell Tissue Res ; 379(2): 261-273, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31440818

RESUMO

An extreme reduction in body size has been shown to negatively impact the memory retention level of the parasitic wasp Nasonia vitripennis. In addition, N. vitripennis and Nasonia giraulti, closely related parasitic wasps, differ markedly in the number of conditioning trials required to form long-term memory. These differences in memory dynamics may be associated with differences in the dopaminergic neurons in the Nasonia brains. Here, we used dopamine immunoreactivity to identify and count the number of cell bodies in dopaminergic clusters of normal- and small-sized N. vitripennis and normal-sized N. giraulti. We counted in total a maximum of approximately 160 dopaminergic neurons per brain. These neurons were present in 9 identifiable clusters (D1a, D1b, D2, D3, D4a, D4b, D5, D6 and D7). Our analysis revealed that N. giraulti had fewer cells in the D2 and D4a clusters but more in D4b, compared with normal-sized N. vitripennis. In addition, we found fewer cells in the D5 and D7 cluster of small-sized N. vitripennis compared to normal-sized N. vitripennis. A comparison of our findings with the literature on dopaminergic clusters in the fruit fly Drosophila melanogaster and the honey bee Apis mellifera indicates that clusters D2, D3 and D5 may play a role in memory formation in Nasonia wasps. The results from both the species comparison and the size comparison are therefore of high interest and importance for our understanding of the complex intricacies that underlie the memory dynamics of insects.


Assuntos
Tamanho Corporal , Encéfalo/anatomia & histologia , Dopamina/metabolismo , Vespas/anatomia & histologia , Animais , Corpo Celular/metabolismo , Tamanho do Órgão , Especificidade da Espécie , Coloração e Rotulagem
4.
J Evol Biol ; 32(7): 694-705, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30929291

RESUMO

Heritable genetic variation in relative brain size can underlie the relationship between brain performance and the relative size of the brain. We used bidirectional artificial selection to study the consequences of genetic variation in relative brain size on brain morphology, cognition and longevity in Nasonia vitripennis parasitoid wasps. Our results show a robust change in relative brain size after 26 generations of selection and six generations of relaxation. Total average neuropil volume of the brain was 16% larger in wasps selected for relatively large brains than in wasps selected for relatively small brains, whereas the body length of the large-brained wasps was smaller. Furthermore, the relative volume of the antennal lobes was larger in wasps with relatively large brains. Relative brain size did not influence olfactory memory retention, whereas wasps that were selected for larger relative brain size had a shorter longevity, which was even further reduced after a learning experience. These effects of genetic variation on neuropil composition and memory retention are different from previously described effects of phenotypic plasticity in absolute brain size. In conclusion, having relatively large brains may be costly for N. vitripennis, whereas no cognitive benefits were recorded.


Assuntos
Encéfalo/anatomia & histologia , Seleção Genética , Vespas/anatomia & histologia , Vespas/genética , Animais , Encéfalo/crescimento & desenvolvimento , Feminino , Longevidade/genética , Longevidade/fisiologia , Memória/fisiologia , Vespas/fisiologia
5.
Cell Tissue Res ; 369(3): 477-496, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28597098

RESUMO

The parasitic wasp, Trichogramma evanescens, is an extremely small insect, with a body length as small as 0.3 mm. To facilitate this miniaturization, their brains may have evolved to contain smaller neural components and/or reduced neural complexity than larger insects. Here, we study whether the size and number of neurons are reduced in the miniaturized brain of T. evanescens, focusing on neurons that express serotonin (5HT), octopamine (OA) and dopamine (DA). We provide the first description of the distribution, projection patterns and number of 5HT-, OA- and DA-like immunoreactive cell bodies in T. evanescens and compare our observations with descriptions of much larger insects. The brains of T. evanescens contain comparable numbers of monoaminergic neurons to those of larger insects. Serotonergic neurons appear to be especially conserved; most of the clusters contain a similar number of neurons to those described in Apis mellifera and Drosophila melanogaster. This maintained complexity may have been facilitated by miniaturization of neuron size. However, many dopaminergic and some octopaminergic neuron clusters in T. evanescens contain fewer neurons than in larger insects. Modification of the complexity of these monoaminergic systems may have been necessary to maintain neuron functionality during brain miniaturization in T. evanescens. Our results reveal some of the evolutionary adaptations that may enable behavioural and cognitive complexity with respect to miniaturized brains.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/citologia , Dopamina/metabolismo , Octopamina/metabolismo , Parasitos/anatomia & histologia , Neurônios Serotoninérgicos/metabolismo , Vespas/anatomia & histologia , Animais , Feminino , Neurônios Serotoninérgicos/citologia
6.
Brain Behav Evol ; 89(3): 185-194, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28478445

RESUMO

Trichogramma evanescens parasitic wasps show large phenotypic plasticity in brain and body size, resulting in a 5-fold difference in brain volume among genetically identical sister wasps. Brain volume scales linearly with body volume in these wasps. This isometric brain scaling forms an exception to Haller's rule, which states that small animals have relatively larger brains than large animals. The large plasticity in brain size may be facilitated by plasticity in neuron size, in the number of neurons, or both. Here, we investigated whether brain isometry requires plasticity in the number and size of monoaminergic neurons that express serotonin (5HT), octopamine (OA), and dopamine (DA). Genetically identical small and large T. evanescens appear to have the same number of 5HT-, OA-, and DA-like immunoreactive cell bodies in their brains, but these cell bodies differ in diameter. This indicates that brain isometry can be facilitated by plasticity in the size of monoaminergic neurons, rather than plasticity in numbers of monoaminergic neurons. Selection pressures on body miniaturization may have resulted in the evolution of miniaturized neural pathways that allow even the smallest wasps to find suitable hosts. Plasticity in the size of neural components may be among the mechanisms that underlie isometric brain scaling while maintaining cognitive abilities in the smallest individuals.


Assuntos
Tamanho Corporal/genética , Neurônios/fisiologia , Vespas/fisiologia , Animais , Evolução Biológica , Encéfalo/fisiologia , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/fisiologia , Sistema Nervoso , Neurônios/metabolismo , Fenótipo , Receptores de Amina Biogênica/metabolismo , Receptores de Amina Biogênica/fisiologia , Neurônios Serotoninérgicos/metabolismo , Neurônios Serotoninérgicos/fisiologia , Vespas/metabolismo
7.
Brain Behav Evol ; 90(3): 243-254, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29059675

RESUMO

Haller's rule states that brains scale allometrically with body size in all animals, meaning that relative brain size increases with decreasing body size. This rule applies both on inter- and intraspecific comparisons. Only 1 species, the extremely small parasitic wasp Trichogramma evanescens, is known as an exception and shows an isometric brain-body size relation in an intraspecific comparison between differently sized individuals. Here, we investigated if such an isometric brain-body size relationship also occurs in an intraspecific comparison with a slightly larger parasitic wasp, Nasonia vitripennis, a species that may vary 10-fold in body weight upon differences in levels of scramble competition during larval development. We show that Nasonia exhibits diphasic brain-body size scaling: larger wasps scale allometrically, following Haller's rule, whereas the smallest wasps show isometric scaling. Brains of smaller wasps are, therefore, smaller than expected and we hypothesized that this may lead to adaptations in brain architecture. Volumetric analysis of neuropil composition revealed that wasps of different sizes differed in relative volume of multiple neuropils. The optic lobes and mushroom bodies in particular were smaller in the smallest wasps. Furthermore, smaller brains had a relatively smaller total neuropil volume and larger cellular rind than large brains. These changes in relative brain size and brain architecture suggest that the energetic constraints on brain tissue outweigh specific cognitive requirements in small Nasonia wasps.


Assuntos
Tamanho Corporal/fisiologia , Encéfalo/anatomia & histologia , Vespas/anatomia & histologia , Adaptação Fisiológica/fisiologia , Animais , Evolução Biológica , Corpos Pedunculados/anatomia & histologia , Neurópilo/fisiologia , Lobo Óptico de Animais não Mamíferos/anatomia & histologia
8.
BMC Genomics ; 16: 162, 2015 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-25888126

RESUMO

BACKGROUND: Cellular processes underlying memory formation are evolutionary conserved, but natural variation in memory dynamics between animal species or populations is common. The genetic basis of this fascinating phenomenon is poorly understood. Closely related species of Nasonia parasitic wasps differ in long-term memory (LTM) formation: N. vitripennis will form transcription-dependent LTM after a single conditioning trial, whereas the closely-related species N. giraulti will not. Genes that were differentially expressed (DE) after conditioning in N. vitripennis, but not in N. giraulti, were identified as candidate genes that may regulate LTM formation. RESULTS: RNA was collected from heads of both species before and immediately, 4 or 24 hours after conditioning, with 3 replicates per time point. It was sequenced strand-specifically, which allows distinguishing sense from antisense transcripts and improves the quality of expression analyses. We determined conditioning-induced DE compared to naïve controls for both species. These expression patterns were then analysed with GO enrichment analyses for each species and time point, which demonstrated an enrichment of signalling-related genes immediately after conditioning in N. vitripennis only. Analyses of known LTM genes and genes with an opposing expression pattern between the two species revealed additional candidate genes for the difference in LTM formation. These include genes from various signalling cascades, including several members of the Ras and PI3 kinase signalling pathways, and glutamate receptors. Interestingly, several other known LTM genes were exclusively differentially expressed in N. giraulti, which may indicate an LTM-inhibitory mechanism. Among the DE transcripts were also antisense transcripts. Furthermore, antisense transcripts aligning to a number of known memory genes were detected, which may have a role in regulating these genes. CONCLUSION: This study is the first to describe and compare expression patterns of both protein-coding and antisense transcripts, at different time points after conditioning, of two closely related animal species that differ in LTM formation. Several candidate genes that may regulate differences in LTM have been identified. This transcriptome analysis is a valuable resource for future in-depth studies to elucidate the role of candidate genes and antisense transcription in natural variation in LTM formation.


Assuntos
Encéfalo/metabolismo , Himenópteros/genética , Memória de Longo Prazo/fisiologia , Odorantes , Transcriptoma , Processamento Alternativo , Animais , Feminino , Aromatizantes/farmacologia , Himenópteros/metabolismo , Memória de Longo Prazo/efeitos dos fármacos , Oligorribonucleotídeos Antissenso/metabolismo , RNA/análise , RNA/isolamento & purificação , RNA/metabolismo , Interferência de RNA , RNA Longo não Codificante/análise , RNA Longo não Codificante/isolamento & purificação , RNA Longo não Codificante/metabolismo , Análise de Sequência de RNA
9.
BMC Plant Biol ; 15: 165, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26122266

RESUMO

BACKGROUND: Chrysomela populi (poplar leaf beetle) is a common herbivore in poplar plantations whose infestation causes major economic losses. Because plant volatiles act as infochemicals, we tested whether isoprene, the main volatile organic compound (VOC) produced by poplars (Populus x canescens), affects the performance of C. populi employing isoprene emitting (IE) and transgenic isoprene non-emitting (NE) plants. Our hypothesis was that isoprene is sensed and affects beetle orientation or that the lack of isoprene affects plant VOC profiles and metabolome with consequences for C. populi feeding. RESULTS: Electroantennographic analysis revealed that C. populi can detect higher terpenes, but not isoprene. In accordance to the inability to detect isoprene, C. populi showed no clear preference for IE or NE poplar genotypes in the choice experiments, however, the beetles consumed a little bit less leaf mass and laid fewer eggs on NE poplar trees in field experiments. Slight differences in the profiles of volatile terpenoids between IE and NE genotypes were detected by gas chromatography - mass spectrometry. Non-targeted metabolomics analysis by Fourier Transform Ion Cyclotron Resonance Mass Spectrometer revealed genotype-, time- and herbivore feeding-dependent metabolic changes both in the infested and adjacent undamaged leaves under field conditions. CONCLUSIONS: We show for the first time that C. populi is unable to sense isoprene. The detected minor differences in insect feeding in choice experiments and field bioassays may be related to the revealed changes in leaf volatile emission and metabolite composition between the IE and NE poplars. Overall our results indicate that lacking isoprene emission is of minor importance for C. populi herbivory under natural conditions, and that the lack of isoprene is not expected to change the economic losses in poplar plantations caused by C. populi infestation.


Assuntos
Butadienos/metabolismo , Quimiotaxia , Besouros/fisiologia , Hemiterpenos/metabolismo , Herbivoria , Pentanos/metabolismo , Populus/metabolismo , Animais , Biomassa , Feminino , Cadeia Alimentar , Agricultura Florestal , Masculino , Metaboloma , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Populus/genética , Compostos Orgânicos Voláteis/metabolismo
10.
Cell Tissue Res ; 358(2): 313-29, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25107606

RESUMO

Octopamine is an important neuromodulator in the insect nervous system, influencing memory formation, sensory perception and motor control. In this study, we compare the distribution of octopamine-like immunoreactive neurons in two parasitic wasp species of the Nasonia genus, N. vitripennis and N. giraulti. These two species were previously described as differing in their learning and memory formation, which raised the question as to whether morphological differences in octopaminergic neurons underpinned these variations. Immunohistochemistry in combination with confocal laser scanning microscopy was used to reveal and compare the somata and major projections of the octopaminergic neurons in these wasps. The brains of both species showed similar staining patterns, with six different neuron clusters being identified in the brain and five different clusters in the subesophageal ganglion. Of those clusters found in the subesophageal ganglion, three contained unpaired neurons, whereas the other three consisted in paired neurons. The overall pattern of octopaminergic neurons in both species was similar, with no differences in the numbers or projections of the ventral unpaired median (VUM) neurons, which are known to be involved in memory formation in insects. In one other cluster in the brain, located in-between the optic lobe and the antennal lobe, we detected more neurons in N. vitripennis compared with N. giraulti. Combining our results with findings made previously in other Hymenopteran species, we discuss possible functions and some of the ultimate factors influencing the evolution of the octopaminergic system in the insect brain.


Assuntos
Encéfalo/citologia , Esôfago/inervação , Gânglios dos Invertebrados/citologia , Neurônios/citologia , Octopamina/imunologia , Parasitos/citologia , Vespas/citologia , Animais , Corpo Celular/metabolismo , Feminino , Gânglios dos Invertebrados/anatomia & histologia , Neurônios/metabolismo , Neurópilo/metabolismo
11.
Insect Sci ; 31(2): 469-488, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38105530

RESUMO

The olfactory system of adult lepidopterans is among the best described neuronal circuits. However, comparatively little is known about the organization of the olfactory system in the larval stage of these insects. Here, we explore the expression of olfactory receptors and the organization of olfactory sensory neurons in caterpillars of Pieris brassicae, a significant pest species in Europe and a well-studied species for its chemical ecology. To describe the larval olfactory system in this species, we first analyzed the head transcriptome of third-instar larvae (L3) and identified 16 odorant receptors (ORs) including the OR coreceptor (Orco), 13 ionotropic receptors (IRs), and 8 gustatory receptors (GRs). We then quantified the expression of these 16 ORs in different life stages, using qPCR, and found that the majority of ORs had significantly higher expression in the L4 stage than in the L3 and L5 stages, indicating that the larval olfactory system is not static throughout caterpillar development. Using an Orco-specific antibody, we identified all olfactory receptor neurons (ORNs) expressing the Orco protein in L3, L4, and L5 caterpillars and found a total of 34 Orco-positive ORNs, distributed among three sensilla on the antenna. The number of Orco-positive ORNs did not differ among the three larval instars. Finally, we used retrograde axon tracing of the antennal nerve and identified a mean of 15 glomeruli in the larval antennal center (LAC), suggesting that the caterpillar olfactory system follows a similar design as the adult olfactory system, although with a lower numerical redundancy. Taken together, our results provide a detailed analysis of the larval olfactory neurons in P. brassicae, highlighting both the differences as well as the commonalities with the adult olfactory system. These findings contribute to a better understanding of the development of the olfactory system in insects and its life-stage-specific adaptations.


Assuntos
Lepidópteros , Neurônios Receptores Olfatórios , Receptores Odorantes , Animais , Neurônios Receptores Olfatórios/metabolismo , Insetos/fisiologia , Larva/metabolismo , Sensilas/metabolismo , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo
12.
Brain Behav Evol ; 81(2): 86-92, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23363733

RESUMO

Throughout the animal kingdom, Haller's rule holds that smaller individuals have larger brains relative to their body than larger-bodied individuals. Such brain-body size allometry is documented for all animals studied to date, ranging from small ants to the largest mammals. However, through experimental induction of natural variation in body size, and 3-D reconstruction of brain and body volume, we here show an isometric brain-body size relationship in adults of one of the smallest insect species on Earth, the parasitic wasp Trichogramma evanescens. The relative brain volume constitutes on average 8.2% of the total body volume. Brain-body size isometry may be typical for the smallest species with a rich behavioural and cognitive repertoire: a further increase in expensive brain tissue relative to body size would be too costly in terms of energy expenditure. This novel brain scaling strategy suggests a hitherto unknown flexibility in neuronal architecture and brain modularity.


Assuntos
Tamanho Corporal , Encéfalo/anatomia & histologia , Vespas/anatomia & histologia , Animais , Tamanho Corporal/genética , Genótipo , Microscopia Confocal , Tamanho do Órgão , Vespas/genética
13.
Proc Natl Acad Sci U S A ; 106(3): 820-5, 2009 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-19139416

RESUMO

Many insects possess a sexual communication system that is vulnerable to chemical espionage by parasitic wasps. We recently discovered that a hitch-hiking (H) egg parasitoid exploits the antiaphrodisiac pheromone benzyl cyanide (BC) of the Large Cabbage White butterfly Pieris brassicae. This pheromone is passed from male butterflies to females during mating to render them less attractive to conspecific males. When the tiny parasitic wasp Trichogramma brassicae detects the antiaphrodisiac, it rides on a mated female butterfly to a host plant and then parasitizes her freshly laid eggs. The present study demonstrates that a closely related generalist wasp, Trichogramma evanescens, exploits BC in a similar way, but only after learning. Interestingly, the wasp learns to associate an H response to the odors of a mated female P. brassicae butterfly with reinforcement by parasitizing freshly laid butterfly eggs. Behavioral assays, before which we specifically inhibited long-term memory (LTM) formation with a translation inhibitor, reveal that the wasp has formed protein synthesis-dependent LTM at 24 h after learning. To our knowledge, the combination of associatively learning to exploit the sexual communication system of a host and the formation of protein synthesis-dependent LTM after a single learning event has not been documented before. We expect it to be widespread in nature, because it is highly adaptive in many species of egg parasitoids. Our finding of the exploitation of an antiaphrodisiac by multiple species of parasitic wasps suggests its use by Pieris butterflies to be under strong selective pressure.


Assuntos
Afrodisíacos/antagonistas & inibidores , Borboletas/parasitologia , Aprendizagem , Comportamento Sexual Animal , Vespas/fisiologia , Acetonitrilas , Animais , Brassica/parasitologia , Condicionamento Operante , Feminino , Masculino , Memória
14.
Ecol Lett ; 14(7): 670-6, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21592275

RESUMO

Communities are riddled with indirect species interactions and these interactions can be modified by organisms that are parasitic or symbiotic with one of the indirectly interacting species. By inducing plant responses, herbivores are well known to alter the plant quality for subsequent feeders. The reduced performance of herbivores on induced plants cascades into effects on the performance of higher trophic level organisms such as parasitoids that develop inside herbivores. Parasitoids themselves may also, indirectly, interact with the host plant by affecting the behaviour and physiology of their herbivorous host. Here, we show that, through their herbivorous host, larvae of two parasitoid species differentially affect plant phenotypes leading to asymmetric interactions among parasitoid larvae developing in different hosts that feed on the same plant. Our results show that temporally separated parasitoid larvae are involved in indirect plant-mediated interactions by a network of trophic and non-trophic relationships.


Assuntos
Brassica/fisiologia , Borboletas/parasitologia , Vespas/fisiologia , Animais , Borboletas/fisiologia , Interações Hospedeiro-Parasita , Larva/fisiologia , Dinâmica Populacional
15.
Proc Biol Sci ; 278(1707): 889-97, 2011 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-21106587

RESUMO

Although the neural and genetic pathways underlying learning and memory formation seem strikingly similar among species of distant animal phyla, several more subtle inter- and intraspecific differences become evident from studies on model organisms. The true significance of such variation can only be understood when integrating this with information on the ecological relevance. Here, we argue that parasitoid wasps provide an excellent opportunity for multi-disciplinary studies that integrate ultimate and proximate approaches. These insects display interspecific variation in learning rate and memory dynamics that reflects natural variation in a daunting foraging task that largely determines their fitness: finding the inconspicuous hosts to which they will assign their offspring to develop. We review bioassays used for oviposition learning, the ecological factors that are considered to underlie the observed differences in learning rate and memory dynamics, and the opportunities for convergence of ecology and neuroscience that are offered by using parasitoid wasps as model species. We advocate that variation in learning and memory traits has evolved to suit an insect's lifestyle within its ecological niche.


Assuntos
Aprendizagem , Memória , Vespas/fisiologia , Animais , Comportamento Animal , Ecologia , Rede Nervosa , Neurociências , Oviposição , Especificidade da Espécie , Fatores de Tempo , Vespas/genética
16.
Behav Ecol ; 32(5): 952-960, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34690548

RESUMO

Animals can alter their foraging behavior through associative learning, where an encounter with an essential resource (e.g., food or a reproductive opportunity) is associated with nearby environmental cues (e.g., volatiles). This can subsequently improve the animal's foraging efficiency. However, when these associated cues are encountered again, the anticipated resource is not always present. Such an unrewarding experience, also called a memory-extinction experience, can change an animal's response to the associated cues. Although some studies are available on the mechanisms of this process, they rarely focus on cues and rewards that are relevant in an animal's natural habitat. In this study, we tested the effect of different types of ecologically relevant memory-extinction experiences on the conditioned plant volatile preferences of the parasitic wasp Cotesia glomerata that uses these cues to locate its caterpillar hosts. These extinction experiences consisted of contact with only host traces (frass and silk), contact with nonhost traces, or oviposition in a nonhost near host traces, on the conditioned plant species. Our results show that the lack of oviposition, after contacting host traces, led to the temporary alteration of the conditioned plant volatile preference in C. glomerata, but this effect was plant species-specific. These results provide novel insights into how ecologically relevant memory-extinction experiences can fine-tune an animal's foraging behavior. This fine-tuning of learned behavior can be beneficial when the lack of finding a resource accurately predicts current, but not future foraging opportunities. Such continuous reevaluation of obtained information helps animals to prevent maladaptive foraging behavior.

17.
Commun Biol ; 4(1): 104, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33483589

RESUMO

Endogenous viruses form an important proportion of eukaryote genomes and a source of novel functions. How large DNA viruses integrated into a genome evolve when they confer a benefit to their host, however, remains unknown. Bracoviruses are essential for the parasitism success of parasitoid wasps, into whose genomes they integrated ~103 million years ago. Here we show, from the assembly of a parasitoid wasp genome at a chromosomal scale, that bracovirus genes colonized all ten chromosomes of Cotesia congregata. Most form clusters of genes involved in particle production or parasitism success. Genomic comparison with another wasp, Microplitis demolitor, revealed that these clusters were already established ~53 mya and thus belong to remarkably stable genomic structures, the architectures of which are evolutionary constrained. Transcriptomic analyses highlight temporal synchronization of viral gene expression without resulting in immune gene induction, suggesting that no conflicts remain between ancient symbiotic partners when benefits to them converge.


Assuntos
Evolução Biológica , Cromossomos de Insetos , Genoma de Inseto , Polydnaviridae/genética , Vespas/genética , Animais , Sequência de Bases , Sequência Conservada , Nudiviridae/genética , Receptores Odorantes/genética , Olfato , Simbiose , Sintenia , Vespas/virologia
18.
Curr Opin Insect Sci ; 42: 47-54, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32947014

RESUMO

Parasitic wasps and their larval hosts are intimately connected by an array of behavioral adaptations and counter-adaptations. This co-evolution has led to highly specific, natural variation in learning rates and memory consolidation in parasitoid wasps. Similarly, the hosts of the parasitoids show specific sensory adaptations as well as non-associative learning strategies for parasitoid avoidance. However, these neuronal and behavioral adaptations of both hosts and wasps have so far been studied largely apart from each other. Here we argue that a parallel investigation of the nervous system in wasps and their hosts might lead to novel insights into the evolution of insect behavior and the neurobiology of learning and memory.


Assuntos
Adaptação Fisiológica , Interações Hospedeiro-Parasita , Aprendizagem , Vespas/fisiologia , Animais , Larva/parasitologia
19.
Arthropod Struct Dev ; 51: 41-51, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31357033

RESUMO

Nasonia, a genus of parasitoid wasps, is a promising model system in the study of developmental and evolutionary genetics, as well as complex traits such as learning. Of these "jewel wasps", the species Nasonia vitripennis is widely spread and widely studied. To accelerate neuroscientific research in this model species, fundamental knowledge of its nervous system is needed. To this end, we present an average standard brain of recently eclosed naïve female N. vitripennis wasps obtained by the iterative shape averaging method. This "Jewel Wasp Standard Brain" includes the optic lobe (excluding the lamina), the anterior optic tubercle, the antennal lobe, the lateral horn, the mushroom body, the central complex, and the remaining unclassified neuropils in the central brain. Furthermore, we briefly describe these well-defined neuropils and their subregions in the N. vitripennis brain. A volumetric analysis of these neuropils is discussed in the context of brains of other insect species. The Jewel Wasp Standard Brain will provide a framework to integrate and consolidate the results of future neurobiological studies in N. vitripennis. In addition, the volumetric analysis provides a baseline for future work on age- and experience-dependent brain plasticity.


Assuntos
Vespas/anatomia & histologia , Animais , Encéfalo/anatomia & histologia , Encéfalo/citologia , Feminino , Neurópilo/citologia
20.
Brain Res ; 1712: 158-166, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30711401

RESUMO

The Drosophila olfactory system provides an excellent model to elucidate the neural circuits that control behaviors elicited by environmental stimuli. Despite significant progress in defining olfactory circuit components and their connectivity, little is known about the mechanisms that transfer the information from the primary antennal olfactory receptor neurons to the higher order brain centers. Here, we show that the Dystrophin Dp186 isoform is required in the olfactory system circuit for olfactory functions. Using two-photon calcium imaging, we found the reduction of calcium influx in olfactory receptor neurons (ORNs) and also the defect of GABAA mediated inhibitory input in the projection neurons (PNs) in Dp186 mutation. Moreover, the Dp186 mutant flies which display a decreased odor avoidance behavior were rescued by Dp186 restoration in the Drosophila olfactory neurons in either the presynaptic ORNs or the postsynaptic PNs. Therefore, these results revealed a role for Dystrophin, Dp 186 isoform in gain control of the olfactory synapse via the modulation of excitatory and inhibitory synaptic inputs to olfactory projection neurons.


Assuntos
Distrofina/metabolismo , Condutos Olfatórios/fisiologia , Olfato/fisiologia , Animais , Cálcio/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Distrofina/fisiologia , Feminino , Interneurônios/metabolismo , Masculino , Odorantes , Percepção Olfatória/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Sinapses/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA