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Current Opinion in Neurobiology Dec 2020Visually guided decision-making requires integration of information from distributed brain areas, necessitating a brain-wide approach to examine its neural mechanisms.... (Review)
Review
Visually guided decision-making requires integration of information from distributed brain areas, necessitating a brain-wide approach to examine its neural mechanisms. New tools in Drosophila melanogaster enable circuits spanning the brain to be charted with single cell-type resolution. Here, we highlight recent advances uncovering the computations and circuits that transform and integrate visual information across the brain to make behavioral choices. Visual information flows from the optic lobes to three primary central brain regions: a sensorimotor mapping area and two 'higher' centers for memory or spatial orientation. Rapid decision-making during predator evasion emerges from the spike timing dynamics in parallel sensorimotor cascades. Goal-directed decisions may occur through memory, navigation and valence processing in the central complex and mushroom bodies.
Topics: Animals; Brain; Drosophila; Drosophila melanogaster; Memory; Mushroom Bodies
PubMed: 33217639
DOI: 10.1016/j.conb.2020.10.010 -
Genetics Nov 2007Over the course of the past century, flies in the family Drosophilidae have been important models for understanding genetic, developmental, cellular, ecological, and... (Review)
Review
Over the course of the past century, flies in the family Drosophilidae have been important models for understanding genetic, developmental, cellular, ecological, and evolutionary processes. Full genome sequences from a total of 12 species promise to extend this work by facilitating comparative studies of gene expression, of molecules such as proteins, of developmental mechanisms, and of ecological adaptation. Here we review basic biological and ecological information of the species whose genomes have recently been completely sequenced in the context of current research.
Topics: Animals; Behavior, Animal; Biological Evolution; Drosophila; Ecosystem; Gene Rearrangement; Genome, Insect; Genomics; Phylogeny; Species Specificity
PubMed: 18039866
DOI: 10.1534/genetics.107.074112 -
Current Biology : CB Aug 2020Maternal decisions, such as where to build a nest or where to lay your eggs, are critical for the offspring's fitness and survival in any species. A new study in...
Maternal decisions, such as where to build a nest or where to lay your eggs, are critical for the offspring's fitness and survival in any species. A new study in Drosophila now reveals that distinct classes of mechanosensory receptors and neurons fine tune the physical assessment of an oviposition site and determine where the female fly lays her eggs.
Topics: Animals; Drosophila; Drosophila melanogaster; Eggs; Female; Neurons; Oviposition
PubMed: 32810453
DOI: 10.1016/j.cub.2020.06.082 -
Neuroscience and Biobehavioral Reviews Nov 2022NASA is planning to resume human-crewed lunar missions and lay the foundation for human exploration to Mars. However, our knowledge of the overall effects of... (Review)
Review
NASA is planning to resume human-crewed lunar missions and lay the foundation for human exploration to Mars. However, our knowledge of the overall effects of long-duration spaceflight on human physiology is limited. During spaceflight, astronauts are exposed to multiple risk factors, including gravitational changes, ionizing radiation, physiological stress, and altered circadian lighting. These factors contribute to pathophysiological responses that target different organ systems in the body. This review discusses the advancements in gravitational biology using Drosophila melanogaster, one of the first organisms to be launched into space. As a well-established spaceflight model organism, fruit flies have yielded significant information, including neurobehavioral, aging, immune, cardiovascular, developmental, and multi-omics changes across tissues and developmental stages, as detailed in this review.
Topics: Humans; Animals; Drosophila melanogaster; Space Flight; Astronauts; Gravitation; Drosophila
PubMed: 36126744
DOI: 10.1016/j.neubiorev.2022.104880 -
Genetics Jan 2023
Topics: Animals; Drosophila; Eye; Drosophila melanogaster
PubMed: 36370082
DOI: 10.1093/genetics/iyac169 -
The Journal of Neuroscience : the... Sep 2023The structure of neural circuitry plays a crucial role in brain function. Previous studies of brain organization generally had to trade off between coarse descriptions...
The structure of neural circuitry plays a crucial role in brain function. Previous studies of brain organization generally had to trade off between coarse descriptions at a large scale and fine descriptions on a small scale. Researchers have now reconstructed tens to hundreds of thousands of neurons at synaptic resolution, enabling investigations into the interplay between global, modular organization, and cell type-specific wiring. Analyzing data of this scale, however, presents unique challenges. To address this problem, we applied novel community detection methods to analyze the synapse-level reconstruction of an adult female brain containing >20,000 neurons and 10 million synapses. Using a machine-learning algorithm, we find the most densely connected communities of neurons by maximizing a generalized modularity density measure. We resolve the community structure at a range of scales, from large (on the order of thousands of neurons) to small (on the order of tens of neurons). We find that the network is organized hierarchically, and larger-scale communities are composed of smaller-scale structures. Our methods identify well-known features of the fly brain, including its sensory pathways. Moreover, focusing on specific brain regions, we are able to identify subnetworks with distinct connectivity types. For example, manual efforts have identified layered structures in the fan-shaped body. Our methods not only automatically recover this layered structure, but also resolve finer connectivity patterns to downstream and upstream areas. We also find a novel modular organization of the superior neuropil, with distinct clusters of upstream and downstream brain regions dividing the neuropil into several pathways. These methods show that the fine-scale, local network reconstruction made possible by modern experimental methods are sufficiently detailed to identify the organization of the brain across scales, and enable novel predictions about the structure and function of its parts. The Hemibrain is a partial connectome of an adult female brain containing >20,000 neurons and 10 million synapses. Analyzing the structure of a network of this size requires novel and efficient computational tools. We applied a new community detection method to automatically uncover the modular structure in the Hemibrain dataset by maximizing a generalized modularity measure. This allowed us to resolve the community structure of the fly hemibrain at a range of spatial scales revealing a hierarchical organization of the network, where larger-scale modules are composed of smaller-scale structures. The method also allowed us to identify subnetworks with distinct cell and connectivity structures, such as the layered structures in the fan-shaped body, and the modular organization of the superior neuropil. Thus, network analysis methods can be adopted to the connectomes being reconstructed using modern experimental methods to reveal the organization of the brain across scales. This supports the view that such connectomes will allow us to uncover the organizational structure of the brain, which can ultimately lead to a better understanding of its function.
Topics: Female; Animals; Drosophila; Drosophila melanogaster; Connectome; Brain; Neurons; Pentaerythritol Tetranitrate
PubMed: 37591738
DOI: 10.1523/JNEUROSCI.0134-23.2023 -
Development Genes and Evolution Dec 2022The origin, diversification, and secondary loss of sexually dimorphic characters are common in animal evolution. In some cases, structurally and functionally similar...
The origin, diversification, and secondary loss of sexually dimorphic characters are common in animal evolution. In some cases, structurally and functionally similar traits have evolved independently in multiple lineages. Prominent examples of such traits include the male-specific grasping structures that develop on the front legs of many dipteran insects. In this report, we describe the evolution and development of one of these structures, the male-specific "sex brush." The sex brush is composed of densely packed, irregularly arranged modified bristles and is found in several distantly related lineages in the family Drosophilidae. Phylogenetic analysis using 250 genes from over 200 species provides modest support for a single origin of the sex brush followed by many secondary losses; however, independent origins of the sex brush cannot be ruled out completely. We show that sex brushes develop in very similar ways in all brush-bearing lineages. The dense packing of brush hairs is explained by the specification of bristle precursor cells at a near-maximum density permitted by the lateral inhibition mechanism, as well as by the reduced size of the surrounding epithelial cells. In contrast to the female and the ancestral male condition, where bristles are arranged in stereotypical, precisely spaced rows, cell migration does not contribute appreciably to the formation of the sex brush. The complex phylogenetic history of the sex brush can make it a valuable model for investigating coevolution of sex-specific morphology and mating behavior.
Topics: Animals; Male; Female; Phylogeny; Biological Evolution; Drosophilidae; Drosophila melanogaster; Phenotype; Sex Characteristics
PubMed: 35939093
DOI: 10.1007/s00427-022-00694-3 -
BMC Ecology and Evolution Sep 2023No phenotypic trait evolves independently of all other traits, but the cause of trait-trait coevolution is poorly understood. While the coevolution could arise simply...
No phenotypic trait evolves independently of all other traits, but the cause of trait-trait coevolution is poorly understood. While the coevolution could arise simply from pleiotropic mutations that simultaneously affect the traits concerned, it could also result from multivariate natural selection favoring certain trait relationships. To gain a general mechanistic understanding of trait-trait coevolution, we examine the evolution of 220 cell morphology traits across 16 natural strains of the yeast Saccharomyces cerevisiae and the evolution of 24 wing morphology traits across 110 fly species of the family Drosophilidae, along with the variations of these traits among gene deletion or mutation accumulation lines (a.k.a. mutants). For numerous trait pairs, the phenotypic correlation among evolutionary lineages differs significantly from that among mutants. Specifically, we find hundreds of cases where the evolutionary correlation between traits is strengthened or reversed relative to the mutational correlation, which, according to our population genetic simulation, is likely caused by multivariate selection. Furthermore, we detect selection for enhanced modularity of the yeast traits analyzed. Together, these results demonstrate that trait-trait coevolution is shaped by natural selection and suggest that the pleiotropic structure of mutation is not optimal. Because the morphological traits analyzed here are chosen largely because of their measurability and thereby are not expected to be biased with regard to natural selection, our conclusion is likely general.
Topics: Animals; Saccharomyces cerevisiae; Computer Simulation; Drosophilidae; Gene Deletion; Mutation
PubMed: 37700252
DOI: 10.1186/s12862-023-02164-4 -
Frontiers in Cellular and Infection... 2023The fruit fly has emerged as a valuable model for investigating human biology, including the role of the microbiome in health and disease. Historically, studies... (Review)
Review
The fruit fly has emerged as a valuable model for investigating human biology, including the role of the microbiome in health and disease. Historically, studies involving the infection of with single microbial species have yielded critical insights into bacterial colonization and host innate immunity. However, recent evidence has underscored that multiple microbial species can interact in complex ways through physical connections, metabolic cross-feeding, or signaling exchanges, with significant implications for healthy homeostasis and the initiation, progression, and outcomes of disease. As a result, researchers have shifted their focus toward developing more robust and representative models of co-infection to probe the intricacies of polymicrobial synergy and dysbiosis. This review provides a comprehensive overview of the pioneering work and recent advances in the field, highlighting the utility of as an alternative model for studying the multifaceted microbial interactions that occur within the oral cavity and other body sites. We will discuss the factors and mechanisms that drive microbial community dynamics, as well as their impacts on host physiology and immune responses. Furthermore, this review will delve into the emerging evidence that connects oral microbes to systemic conditions in both health and disease. As our understanding of the microbiome continues to evolve, offers a powerful and tractable model for unraveling the complex interplay between host and microbes including oral microbes, which has far-reaching implications for human health and the development of targeted therapeutic interventions.
Topics: Humans; Animals; Drosophila melanogaster; Dysbiosis; Drosophila; Cognition; Coinfection
PubMed: 38192401
DOI: 10.3389/fcimb.2023.1279380 -
Scientific Reports Feb 2021The diverse flora of the Atlantic Forest is fertile ground for discovering new chemical structures with insecticidal activity. The presence of species belonging to the...
The diverse flora of the Atlantic Forest is fertile ground for discovering new chemical structures with insecticidal activity. The presence of species belonging to the genus Baccharis is of particular interest, as these species have shown promise in pest management applications. The objective of this study is to chemically identify the constituents expressed in the leaves of seven species of Baccharis (B. anomala DC., B. calvescens DC., B. mesoneura DC., B. milleflora DC., B. oblongifolia Pers., B. trimera (Less) DC. and B. uncinella DC.) and to evaluate the toxicological and morphological effects caused by essential oils (EOs) on the larvae and adults of Drosophila suzukii (Diptera: Drosophilidae). Chemical analysis using gas chromatography-mass spectrometry (GC-MS) indicated that limonene was the main common constituent in all Baccharis species. This constituent in isolation, as well as the EOs of B. calvescens, B. mesoneura, and B. oblongifolia, caused mortality in over 80% of adults of D. suzukii at a discriminatory concentration of 80 mg L in bioassays of ingestion and topical application. These results are similar to the effect of spinosyn-based synthetic insecticides (spinetoram 75 mg L) 120 h after exposure. Limonene and EOs from all species had the lowest LC and LC values relative to spinosyn and azadirachtin (12 g L) in both bioassays. However, they showed the same time toxicity over time as spinetoram when applied to adults of D. suzukii (LT ranging from 4.6 to 8.7 h) in a topical application bioassay. In olfactometry tests, 92% of D. suzukii females showed repellent behavior when exposed to the EOs and limonene. Likewise, the EOs of B. calvescens, B. mesoneura, and B. oblongifolia significantly reduced the number of eggs in artificial fruits (≅ 7.6 eggs fruit), differing from the control treatment with water (17.2 eggs fruit) and acetone (17.6 eggs fruit). According to histological analyses, the L3 larvae of D. suzukii had morphological and physiological alterations and deformations after exposure to treatments containing EOs and limonene, which resulted in high larval, pupal, and adult mortality. In view of the results, Baccharis EOs and their isolated constituent, limonene, proved to be promising alternatives for developing bioinsecticides to manage of D. suzukii.
Topics: Animals; Baccharis; Drosophila; Fruit; Gas Chromatography-Mass Spectrometry; Insect Repellents; Insecticides; Larva; Limonene; Oils, Volatile; Oviposition; Plant Extracts; Plant Leaves; Pupa
PubMed: 33597617
DOI: 10.1038/s41598-021-83557-7