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PloS One 2020Temperate insect species often enter diapause in preparation for overwintering. One such species is the invasive vinegar fly, Drosophila suzukii (Matsumura), which has...
Temperate insect species often enter diapause in preparation for overwintering. One such species is the invasive vinegar fly, Drosophila suzukii (Matsumura), which has seasonal polymorphisms, considered winter and summer morphs. To date, the morphs have been differentiated by color and size with winter morphs typically being darker and larger compared to summer morphs. 'Dark' and 'large' are subjective, however, and standardizing an identification process can ensure that the morph of interest is being accurately characterized. The goal of our research was to investigate a quantitative method to distinguish between D. suzukii morphs based on body and wing size. We reared winter and summer morph D. suzukii in the laboratory using standard procedures, and measured wing length, wing width, and hind tibia length. Additionally, we collected field D. suzukii to document the seasonal phenology of the morphs in Minnesota based on our model's cutoff criteria. A classification and regression tree analysis were used to determine which metrics would be best for predicting field-caught D. suzukii morphs. Using laboratory-reared flies as our known morphs for the training data in the classification model we developed classification trees based on wing length and the ratio of wing length to hind tibia length. The frequency of winter and summer morphs present in the field varied based on which classification tree was used. Nevertheless, we suggest ratio of wing length to hind tibia length as the most robust criteria for differentiating D. suzukii morphs because the ratio accounts for the size variability between laboratory-reared and field-caught flies and the error rate of misclassification is reduced to 0.01 for males. The results from this work can aid in future D. suzukii research by allowing scientists to objectively differentiate the morphs, and thereby improve our understanding of the biology and phenology of seasonal morph dynamics.
Topics: Animals; Drosophila; Life Cycle Stages; Seasons
PubMed: 32027732
DOI: 10.1371/journal.pone.0228780 -
Biology Letters Feb 2022Animals that ingest toxins can become unpalatable and even toxic to predators and parasites through toxin sequestration. Because most animals rapidly eliminate toxins to...
Animals that ingest toxins can become unpalatable and even toxic to predators and parasites through toxin sequestration. Because most animals rapidly eliminate toxins to survive their ingestion, it is unclear how populations transition from susceptibility and toxin elimination to tolerance and accumulation as chemical defence emerges. Studies of chemical defence have generally focused on species with active toxin sequestration and target-site insensitivity mutations or toxin-binding proteins that permit survival without necessitating toxin elimination. Here, we investigate whether animals that presumably rely on toxin elimination for survival can use ingested toxins for defence. We use the A4 and A3 fly strains from the Drosophila Synthetic Population Resource (DSPR), which respectively possess high and low metabolic nicotine resistance among DSPR fly lines. We find that ingesting nicotine increased A4 but not A3 fly survival against wasp parasitism. Further, we find that despite possessing genetic variants that enhance toxin elimination, A4 flies accrued more nicotine than A3 individuals, likely by consuming more medium. Our results suggest that enhanced toxin metabolism can allow greater toxin intake by offsetting the cost of toxin ingestion. Passive toxin accumulation that accompanies increased toxin intake may underlie the early origins of chemical defence.
Topics: Animals; Drosophila; Drosophila melanogaster; Eating; Nicotine; Toxins, Biological; Wasps
PubMed: 35135316
DOI: 10.1098/rsbl.2021.0579 -
The Journal of Experimental Biology Mar 2021Many animal species show aggression to gain mating partners and to protect territories and other resources from competitors. Both male and female fruit flies of the...
Many animal species show aggression to gain mating partners and to protect territories and other resources from competitors. Both male and female fruit flies of the species exhibit aggression in same-sex pairings, but the strategies used are sexually dimorphic. We have begun to explore the biological basis for the differing aggression strategies, and the cues promoting one form of aggression over the other. Here, we describe a line of genetically masculinized females that switch between male and female aggression patterns based on the sexual identity of their opponents. When these masculinized females are paired with more aggressive opponents, they increase the amount of male-like aggression they use, but do not alter the level of female aggression. This suggests that male aggression may be more highly responsive to behavioral cues than female aggression. Although the masculinized females of this line show opponent-dependent changes in aggression and courtship behavior, locomotor activity and sleep are unaffected. Thus, the driver line used may specifically masculinize neurons involved in social behavior. A discussion of possible different roles of male and female aggression in fruit flies is included here. These results can serve as precursors to future experiments aimed at elucidating the circuitry and triggering cues underlying sexually dimorphic aggressive behavior.
Topics: Animals; Drosophila; Drosophila Proteins; Drosophila melanogaster; Female; Male; Neurons; Sexual Behavior, Animal; Social Behavior
PubMed: 33568440
DOI: 10.1242/jeb.238006 -
Current Opinion in Neurobiology Dec 2020The larva of Drosophila melanogaster is emerging as a powerful model system for comprehensive brain-wide understanding of the circuit implementation of neural... (Review)
Review
The larva of Drosophila melanogaster is emerging as a powerful model system for comprehensive brain-wide understanding of the circuit implementation of neural computations. With an unprecedented amount of tools in hand, including synaptic-resolution connectomics, whole-brain imaging, and genetic tools for selective targeting of single neuron types, it is possible to dissect which circuits and computations are at work behind behaviors that have an interesting level of complexity. Here we present some of the recent advances regarding multisensory integration, learning, and action selection in Drosophila larva.
Topics: Animals; Central Nervous System; Connectome; Drosophila; Drosophila melanogaster; Larva
PubMed: 33242722
DOI: 10.1016/j.conb.2020.09.008 -
Proceedings of the National Academy of... May 2023The degree to which developmental biases affect trait evolution is subject to much debate. Here, we first quantify fluctuating asymmetry as a measure of developmental...
The degree to which developmental biases affect trait evolution is subject to much debate. Here, we first quantify fluctuating asymmetry as a measure of developmental variability, i.e., the propensity of developmental systems to create some phenotypic variants more often than others, and show that it predicts phenotypic and standing genetic variation as well as deep macroevolutionary divergence in wing shape in sepsid flies. Comparing our data to the findings of a previous study demonstrates that developmental variability in the sepsid fly strongly aligns with mutational, standing genetic, and macroevolutionary variation in the Drosophilidae--a group that diverged from the sepsid lineage ca. 64 My ago. We also find that developmental bias in wing shape aligns with the effects of allometry, but less so with putatively adaptive thermal plasticity and population differentiation along latitude. Our findings demonstrate that developmental bias in fly wings predicts evolvability and macroevolutionary trajectories on a much greater scale than previously appreciated but also suggest that causal explanations for such alignments may go beyond simple constraint hypotheses.
Topics: Animals; Biological Evolution; Mutation; Phenotype; Wings, Animal; Drosophilidae
PubMed: 37126721
DOI: 10.1073/pnas.2211210120 -
Journal of Insect Science (Online) May 2023Traditional chemical pesticides pose potential threats to human health, the environment, and food safety, and there is an urgent need to develop botanical pesticides...
Traditional chemical pesticides pose potential threats to human health, the environment, and food safety, and there is an urgent need to develop botanical pesticides that are easily degradable, renewable, and environmentally compatible. This research serves to detect the lethal impacts of Amanita pantherina(DC.:Fr) Schrmm.(Agaricales, Amanitaceae, Amanita), Amanita virgineoides Bas (Agaricales, Amanitaceae, Amanita), Coprinus comatus (O.F.Müll.) Pers. (Agaricales, Psathyrellaceae, Coprinus), Pycnoporus cinnabarinus(Jacq.:Fr) Karst (Polyporales, Polyporaceae, Polyporus) and Phallus rubicundus (Bosc) Fr. (Phallales, Phallaceae, Phallus) on Drosophila melanogaster(Diptera, Drosophilidae, Drosophila), including their effects on lifespan, fecundity, offspring growth and developmental characteristics, antioxidant enzyme activity, peroxide content, and the gene transcription associated with signaling pathways and lifespan of D. melanogaster. The results demonstrated that they all produced lethal effects on D. melanogaster. Female flies were more sensitive to the addition of macrofungi to their diet and have a shorter survival time than male flies. The toxic activity of A. pantherina-supplemented diet was the strongest, so that the D. melanogaster in this group had no offspring. The macrofungal-supplemented diets were able to significantly reduce the activity of antioxidant enzymes, accumulate peroxidation products, up-regulatd the transcription of genes related to signaling pathways, inhibit the expression of longevity genes, reduce the lifespan and fertility of D. melanogaster. Consequently, we hypothetically suggest that medicinal C. comatus, P. cinnabarinus and P. rubicundus hold the potential to be developed into an environmentally friendly biopesticide for fly killing.
Topics: Male; Female; Humans; Animals; Drosophila melanogaster; Antioxidants; Longevity; Drosophila; Fertility
PubMed: 37352434
DOI: 10.1093/jisesa/iead042 -
Genes Jul 2023The evolution of endosymbionts and their hosts can lead to highly dynamic interactions with varying fitness effects for both the endosymbiont and host species. , a...
The evolution of endosymbionts and their hosts can lead to highly dynamic interactions with varying fitness effects for both the endosymbiont and host species. , a ubiquitous endosymbiont of arthropods and nematodes, can have both beneficial and detrimental effects on host fitness. We documented the occurrence and patterns of transmission of within the Hawaiian Drosophilidae and examined the potential contributions of to the rapid diversification of their hosts. Screens for infections across a minimum of 140 species of Hawaiian and revealed species-level infections of 20.0%, and across all 399 samples, a general infection rate of 10.3%. Among the 44 strains we identified using a modified multi-locus strain typing scheme, 30 (68.18%) belonged to supergroup B, five (11.36%) belonged to supergroup A, and nine (20.45%) had alleles with conflicting supergroup assignments. Co-phylogenetic reconciliation analysis indicated that strain diversity within their endemic Hawaiian Drosophilidae hosts can be explained by vertical (e.g., co-speciation) and horizontal (e.g., host switch) modes of transmission. Results from stochastic character trait mapping suggest that horizontal transmission is associated with the preferred oviposition substrate of the host, but not the host's plant family or island of occurrence. For Hawaiian Drosophilid species of conservation concern, with 13 species listed as endangered and 1 listed as threatened, knowledge of strain types, infection status, and potential for superinfection could assist with conservation breeding programs designed to bolster population sizes, especially when wild populations are supplemented with laboratory-reared, translocated individuals. Future research aimed at improving the understanding of the mechanisms of transmission in nature, their impact on the host, and their role in host species formation may shed light on the influence of as an evolutionary driver, especially in Hawaiian ecosystems.
Topics: Female; Animals; Ecosystem; Hawaii; Phylogeny; Wolbachia; Drosophila
PubMed: 37628597
DOI: 10.3390/genes14081545 -
Scientific Reports Mar 2023Cuticle pigmentation was shown to be associated with body temperature for several relatively large species of insects, but it was questioned for small insects. Here we...
Cuticle pigmentation was shown to be associated with body temperature for several relatively large species of insects, but it was questioned for small insects. Here we used a thermal camera to assess the association between drosophilid cuticle pigmentation and body temperature increase when individuals are exposed to light. We compared mutants of large effects within species (Drosophila melanogaster ebony and yellow mutants). Then we analyzed the impact of naturally occurring pigmentation variation within species complexes (Drosophila americana/Drosophila novamexicana and Drosophila yakuba/Drosophila santomea). Finally we analyzed lines of D. melanogaster with moderate differences in pigmentation. We found significant differences in temperatures for each of the four pairs we analyzed. The temperature differences appeared to be proportional to the differently pigmented area: between Drosophila melanogaster ebony and yellow mutants or between Drosophila americana and Drosophila novamexicana, for which the whole body is differently pigmented, the temperature difference was around 0.6 °C ± 0.2 °C. By contrast, between D. yakuba and D. santomea or between Drosophila melanogaster Dark and Pale lines, for which only the posterior abdomen is differentially pigmented, we detected a temperature difference of about 0.14 °C ± 0.10 °C. This strongly suggests that cuticle pigmentation has ecological implications in drosophilids regarding adaptation to environmental temperature.
Topics: Animals; Body Temperature; Drosophila melanogaster; Fever; Drosophila; Pigmentation; Diospyros
PubMed: 36864153
DOI: 10.1038/s41598-023-30652-6 -
Proceedings. Biological Sciences May 2023Understanding how species adapt to different temperatures is crucial to predict their response to global warming, and thermal performance curves (TPCs) have been...
Understanding how species adapt to different temperatures is crucial to predict their response to global warming, and thermal performance curves (TPCs) have been employed recurrently to study this topic. Nevertheless, fundamental questions regarding how thermodynamic constraints and evolution interact to shape TPCs in lineages inhabiting different environments remain unanswered. Here, we study along a latitudinal gradient spanning 3000 km to test opposing hypotheses based on thermodynamic constrains () versus biochemical adaptation () as primary determinants of TPCs variation across populations. We compare thermal responses in metabolic rate and the egg-to-adult survival as descriptors of organismal performance and fitness, respectively, and show that different descriptors of TPCs vary in tandem with mean environmental temperatures, providing strong support to . Thermodynamic constraints also resulted in a strong negative association between maximum performance and thermal breadth. Lastly, we show that descriptors of TPCs for metabolism and egg-to-adult survival are highly correlated, providing evidence of co-adaptation, and that curves for egg-to-adult survival are systematically narrower and displaced toward lower temperatures. Taken together, our results support the pervasive role of thermodynamics constraining thermal responses in populations along a latitudinal gradient, that are only partly compensated by evolutionary adaptation.
Topics: Animals; Temperature; Drosophila; Acclimatization; Thermodynamics; Drosophila simulans
PubMed: 37161321
DOI: 10.1098/rspb.2023.0507 -
Frontiers in Immunology 2023Insects have specialized cell types that participate in the elimination of parasites, for instance, the lamellocytes of the broadly studied species . Other drosophilids,...
BACKGROUND
Insects have specialized cell types that participate in the elimination of parasites, for instance, the lamellocytes of the broadly studied species . Other drosophilids, such as and the invasive , have multinucleated giant hemocytes, a syncytium of blood cells that participate in the encapsulation of the eggs or larvae of parasitoid wasps. These cells can be formed by the fusion of hemocytes in circulation or originate from the lymph gland. Their ultrastructure highly resembles that of the mammalian megakaryocytes.
METHODS
Morphological, protein expressional, and functional features of blood cells were revealed using epifluorescence and confocal microscopy. The respective hemocyte subpopulations were identified using monoclonal antibodies in indirect immunofluorescence assays. Fluorescein isothiocyanate (FITC)-labeled bacteria were used in phagocytosis tests. Gene expression analysis was performed following mRNA sequencing of blood cells.
RESULTS
and encapsulate foreign particles with the involvement of multinucleated giant hemocytes and mount a highly efficient immune response against parasitoid wasps. Morphological, protein expressional, and functional assays of blood cells suggested that these cells could be derived from large plasmatocytes, a unique cell type developing specifically after parasitoid wasp infection. Transcriptomic analysis of blood cells, isolated from naïve and wasp-infected larvae, revealed several differentially expressed genes involved in signal transduction, cell movements, encapsulation of foreign targets, energy production, and melanization, suggesting their role in the anti-parasitoid response. A large number of genes that encode proteins associated with coagulation and wound healing, such as phenoloxidase activity factor-like proteins, fibrinogen-related proteins, lectins, and proteins involved in the differentiation and function of platelets, were constitutively expressed. The remarkable ultrastructural similarities between giant hemocytes and mammalian megakaryocytes, and presence of platelets, and giant cell-derived anucleated fragments at wound sites hint at the involvement of this cell subpopulation in wound healing processes, in addition to participation in the encapsulation reaction.
CONCLUSION
Our observations provide insights into the broad repertoire of blood cell functions required for efficient defense reactions to maintain the homeostasis of the organism. The analysis of the differentiation and function of multinucleated giant hemocytes gives an insight into the diversification of the immune mechanisms.
Topics: Animals; Hemocytes; Drosophila melanogaster; Cell Differentiation; Drosophila; Blood Platelets; Wasps; Mammals
PubMed: 38187383
DOI: 10.3389/fimmu.2023.1322381