1
|
Chechenova M, McLendon L, Dallas B, Stratton H, Kiani K, Gerberich E, Alekseyenko A, Tamba N, An S, Castillo L, Czajkowski E, Talley C, Brown A, Bryantsev AL. Muscle degeneration in aging Drosophila flies: the role of mechanical stress. Skelet Muscle 2024; 14:20. [PMID: 39164781 PMCID: PMC11334408 DOI: 10.1186/s13395-024-00352-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Accepted: 08/09/2024] [Indexed: 08/22/2024] Open
Abstract
Muscle wasting is a universal hallmark of aging which is displayed by a wide range of organisms, although the causes and mechanisms of this phenomenon are not fully understood. We used Drosophila to characterize the phenomenon of spontaneous muscle fiber degeneration (SMFD) during aging. We found that SMFD occurs across diverse types of somatic muscles, progresses with chronological age, and positively correlates with functional muscle decline. Data from vital dyes and morphological markers imply that degenerative fibers most likely die by necrosis. Mechanistically, SMFD is driven by the damage resulting from muscle contractions, and the nervous system may play a significant role in this process. Our quantitative model of SMFD assessment can be useful in identifying and validating novel genetic factors that influence aging-related muscle wasting.
Collapse
Affiliation(s)
- Maria Chechenova
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
- Present Affiliation: MNG Laboratories, A LabCorp Company, Atlanta, GA, USA
| | - Lilla McLendon
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Bracey Dallas
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Hannah Stratton
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Kaveh Kiani
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Erik Gerberich
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Alesia Alekseyenko
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Natasya Tamba
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - SooBin An
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Lizzet Castillo
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Emily Czajkowski
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
- Present Affiliation: Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Christina Talley
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA
| | - Austin Brown
- Department of Mathematics, Kennesaw State University, Kennesaw, GA, USA
| | - Anton L Bryantsev
- Department of Molecular and Cellular Biology, Kennesaw State University, 105 Marietta Dr., NW, Room 4004, MD 1201, Kennesaw, GA, 30144, USA.
| |
Collapse
|
2
|
Kasuya J, Johnson W, Chen HL, Kitamoto T. Dietary Supplementation with Milk Lipids Leads to Suppression of Developmental and Behavioral Phenotypes of Hyperexcitable Drosophila Mutants. Neuroscience 2023; 520:1-17. [PMID: 37004908 PMCID: PMC10200772 DOI: 10.1016/j.neuroscience.2023.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 03/20/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
Dietary modifications often have a profound impact on the penetrance and expressivity of neurological phenotypes that are caused by genetic defects. Our previous studies in Drosophila melanogaster revealed that seizure-like phenotypes of gain-of-function voltage-gated sodium (Nav) channel mutants (paraShu, parabss1, and paraGEFS+), as well as other seizure-prone "bang-sensitive" mutants (eas and sda), were drastically suppressed by supplementation of a standard diet with milk whey. In the current study we sought to determine which components of milk whey are responsible for the diet-dependent suppression of their hyperexcitable phenotypes. Our systematic analysis reveals that supplementing the diet with a modest amount of milk lipids (0.26% w/v) mimics the effects of milk whey. We further found that a minor milk lipid component, α-linolenic acid, contributed to the diet-dependent suppression of adult paraShu phenotypes. Given that lipid supplementation during the larval stages effectively suppressed adult paraShu phenotypes, dietary lipids likely modify neural development to compensate for the defects caused by the mutations. Consistent with this notion, lipid feeding fully rescued abnormal dendrite development of class IV sensory neurons in paraShu larvae. Overall, our findings demonstrate that milk lipids are sufficient to ameliorate hyperexcitable phenotypes in Drosophila mutants, providing a foundation for future investigation of the molecular and cellular mechanisms by which dietary lipids modify genetically induced abnormalities in neural development, physiology, and behavior.
Collapse
Affiliation(s)
- Junko Kasuya
- Department of Anesthesia, Carver College of Medicine, University of Iowa, 1-376 BSB, 51 Newton Road, Iowa City, IA 52242, United States.
| | - Wayne Johnson
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, United States; Interdisciplinary Graduate Program in Genetics, University of Iowa, IA 52242, United States.
| | - Hung-Lin Chen
- Interdisciplinary Graduate Program in Genetics, University of Iowa, IA 52242, United States
| | - Toshihiro Kitamoto
- Interdisciplinary Graduate Program in Genetics, University of Iowa, IA 52242, United States.
| |
Collapse
|
3
|
Chechenova M, Stratton H, Kiani K, Gerberich E, Alekseyenko A, Tamba N, An S, Castillo L, Czajkowski E, Talley C, Bryantsev A. Quantitative model of aging-related muscle degeneration: a Drosophila study. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.19.529145. [PMID: 36865342 PMCID: PMC9980004 DOI: 10.1101/2023.02.19.529145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Changes in the composition and functionality of somatic muscles is a universal hallmark of aging that is displayed by a wide range of species. In humans, complications arising from muscle decline due to sarcopenia aggravate morbidity and mortality rates. The genetics of aging-related deterioration of muscle tissue is not well understood, which prompted us to characterize aging-related muscle degeneration in Drosophila melanogaster (fruit fly), a leading model organism in experimental genetics. Adult flies demonstrate spontaneous degeneration of muscle fibers in all types of somatic muscles, which correlates with functional, chronological, and populational aging. Morphological data imply that individual muscle fibers die by necrosis. Using quantitative analysis, we demonstrate that muscle degeneration in aging flies has a genetic component. Chronic neuronal overstimulation of muscles promotes fiber degeneration rates, suggesting a role for the nervous system in muscle aging. From the other hand, muscles decoupled from neuronal stimulation retain a basal level of spontaneous degeneration, suggesting the presence of intrinsic factors. Based on our characterization, Drosophila can be adopted for systematic screening and validation of genetic factors linked to aging-related muscle loss.
Collapse
Affiliation(s)
- Maria Chechenova
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - Hannah Stratton
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - Kaveh Kiani
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - Erik Gerberich
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - Alesia Alekseyenko
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - Natasya Tamba
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - SooBin An
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - Lizzet Castillo
- Department of Biology, University of New Mexico, Albuquerque, NM
| | - Emily Czajkowski
- Department of Biology, University of New Mexico, Albuquerque, NM
| | - Christina Talley
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| | - Anton Bryantsev
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA
| |
Collapse
|
4
|
Fischer FP, Karge RA, Weber YG, Koch H, Wolking S, Voigt A. Drosophila melanogaster as a versatile model organism to study genetic epilepsies: An overview. Front Mol Neurosci 2023; 16:1116000. [PMID: 36873106 PMCID: PMC9978166 DOI: 10.3389/fnmol.2023.1116000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 01/23/2023] [Indexed: 02/18/2023] Open
Abstract
Epilepsy is one of the most prevalent neurological disorders, affecting more than 45 million people worldwide. Recent advances in genetic techniques, such as next-generation sequencing, have driven genetic discovery and increased our understanding of the molecular and cellular mechanisms behind many epilepsy syndromes. These insights prompt the development of personalized therapies tailored to the genetic characteristics of an individual patient. However, the surging number of novel genetic variants renders the interpretation of pathogenetic consequences and of potential therapeutic implications ever more challenging. Model organisms can help explore these aspects in vivo. In the last decades, rodent models have significantly contributed to our understanding of genetic epilepsies but their establishment is laborious, expensive, and time-consuming. Additional model organisms to investigate disease variants on a large scale would be desirable. The fruit fly Drosophila melanogaster has been used as a model organism in epilepsy research since the discovery of "bang-sensitive" mutants more than half a century ago. These flies respond to mechanical stimulation, such as a brief vortex, with stereotypic seizures and paralysis. Furthermore, the identification of seizure-suppressor mutations allows to pinpoint novel therapeutic targets. Gene editing techniques, such as CRISPR/Cas9, are a convenient way to generate flies carrying disease-associated variants. These flies can be screened for phenotypic and behavioral abnormalities, shifting of seizure thresholds, and response to anti-seizure medications and other substances. Moreover, modification of neuronal activity and seizure induction can be achieved using optogenetic tools. In combination with calcium and fluorescent imaging, functional alterations caused by mutations in epilepsy genes can be traced. Here, we review Drosophila as a versatile model organism to study genetic epilepsies, especially as 81% of human epilepsy genes have an orthologous gene in Drosophila. Furthermore, we discuss newly established analysis techniques that might be used to further unravel the pathophysiological aspects of genetic epilepsies.
Collapse
Affiliation(s)
- Florian P. Fischer
- Department of Epileptology and Neurology, RWTH Aachen University, Aachen, Germany
| | - Robin A. Karge
- Department of Epileptology and Neurology, RWTH Aachen University, Aachen, Germany
| | - Yvonne G. Weber
- Department of Epileptology and Neurology, RWTH Aachen University, Aachen, Germany
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Henner Koch
- Department of Epileptology and Neurology, RWTH Aachen University, Aachen, Germany
| | - Stefan Wolking
- Department of Epileptology and Neurology, RWTH Aachen University, Aachen, Germany
| | - Aaron Voigt
- Department of Neurology, RWTH Aachen University, Aachen, Germany
- JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| |
Collapse
|
5
|
Coulson B, Hunter I, Doran S, Parkin J, Landgraf M, Baines RA. Critical periods in Drosophila neural network development: Importance to network tuning and therapeutic potential. Front Physiol 2022; 13:1073307. [PMID: 36531164 PMCID: PMC9757492 DOI: 10.3389/fphys.2022.1073307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/23/2022] [Indexed: 02/25/2024] Open
Abstract
Critical periods are phases of heightened plasticity that occur during the development of neural networks. Beginning with pioneering work of Hubel and Wiesel, which identified a critical period for the formation of ocular dominance in mammalian visual network connectivity, critical periods have been identified for many circuits, both sensory and motor, and across phyla, suggesting a universal phenomenon. However, a key unanswered question remains why these forms of plasticity are restricted to specific developmental periods rather than being continuously present. The consequence of this temporal restriction is that activity perturbations during critical periods can have lasting and significant functional consequences for mature neural networks. From a developmental perspective, critical period plasticity might enable reproducibly robust network function to emerge from ensembles of cells, whose properties are necessarily variable and fluctuating. Critical periods also offer significant clinical opportunity. Imposed activity perturbation during these periods has shown remarkable beneficial outcomes in a range of animal models of neurological disease including epilepsy. In this review, we spotlight the recent identification of a locomotor critical period in Drosophila larva and describe how studying this model organism, because of its simplified nervous system and an almost complete wired connectome, offers an attractive prospect of understanding how activity during a critical period impacts a neuronal network.
Collapse
Affiliation(s)
- Bramwell Coulson
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Iain Hunter
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Sarah Doran
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Jill Parkin
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Matthias Landgraf
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Richard A. Baines
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| |
Collapse
|
6
|
Jeong J, Lee J, Kim JH, Lim C. Metabolic flux from the Krebs cycle to glutamate transmission tunes a neural brake on seizure onset. PLoS Genet 2021; 17:e1009871. [PMID: 34714823 PMCID: PMC8555787 DOI: 10.1371/journal.pgen.1009871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 10/11/2021] [Indexed: 01/18/2023] Open
Abstract
Kohlschütter-Tönz syndrome (KTS) manifests as neurological dysfunctions, including early-onset seizures. Mutations in the citrate transporter SLC13A5 are associated with KTS, yet their underlying mechanisms remain elusive. Here, we report that a Drosophila SLC13A5 homolog, I'm not dead yet (Indy), constitutes a neurometabolic pathway that suppresses seizure. Loss of Indy function in glutamatergic neurons caused "bang-induced" seizure-like behaviors. In fact, glutamate biosynthesis from the citric acid cycle was limiting in Indy mutants for seizure-suppressing glutamate transmission. Oral administration of the rate-limiting α-ketoglutarate in the metabolic pathway rescued low glutamate levels in Indy mutants and ameliorated their seizure-like behaviors. This metabolic control of the seizure susceptibility was mapped to a pair of glutamatergic neurons, reversible by optogenetic controls of their activity, and further relayed onto fan-shaped body neurons via the ionotropic glutamate receptors. Accordingly, our findings reveal a micro-circuit that links neural metabolism to seizure, providing important clues to KTS-associated neurodevelopmental deficits.
Collapse
Affiliation(s)
- Jiwon Jeong
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jongbin Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Ji-hyung Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Chunghun Lim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- * E-mail:
| |
Collapse
|
7
|
Slo2/K Na Channels in Drosophila Protect against Spontaneous and Induced Seizure-like Behavior Associated with an Increased Persistent Na + Current. J Neurosci 2021; 41:9047-9063. [PMID: 34544836 DOI: 10.1523/jneurosci.0290-21.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/20/2021] [Accepted: 09/13/2021] [Indexed: 11/21/2022] Open
Abstract
Na+ sensitivity is a unique feature of Na+-activated K+ (KNa) channels, making them naturally suited to counter a sudden influx in Na+ ions. As such, it has long been suggested that KNa channels may serve a protective function against excessive excitation associated with neuronal injury and disease. This hypothesis, however, has remained largely untested. Here, we examine KNa channels encoded by the Drosophila Slo2 (dSlo2) gene in males and females. We show that dSlo2/KNa channels are selectively expressed in cholinergic neurons in the adult brain, as well as in glutamatergic motor neurons, where dampening excitation may function to inhibit global hyperactivity and seizure-like behavior. Indeed, we show that effects of feeding Drosophila a cholinergic agonist are exacerbated by the loss of dSlo2/KNa channels. Similar to mammalian Slo2/KNa channels, we show that dSlo2/KNa channels encode a TTX-sensitive K+ conductance, indicating that dSlo2/KNa channels can be activated by Na+ carried by voltage-dependent Na+ channels. We then tested the role of dSlo2/KNa channels in established genetic seizure models in which the voltage-dependent persistent Na+ current (INap) is elevated. We show that the absence of dSlo2/KNa channels increased susceptibility to mechanically induced seizure-like behavior. Similar results were observed in WT flies treated with veratridine, an enhancer of INap Finally, we show that loss of dSlo2/KNa channels in both genetic and pharmacologically primed seizure models resulted in the appearance of spontaneous seizures. Together, our results support a model in which dSlo2/KNa channels, activated by neuronal overexcitation, contribute to a protective threshold to suppress the induction of seizure-like activity.SIGNIFICANCE STATEMENT Slo2/KNa channels are unique in that they constitute a repolarizing K+ pore that is activated by the depolarizing Na+ ion, making them naturally suited to function as a protective "brake" against overexcitation and Na+ overload. Here, we test this hypothesis in vivo by examining how a null mutation of the Drosophila Slo2 (dSlo2)/KNa gene affects seizure-like behavior in genetic and pharmacological models of epilepsy. We show that indeed the loss of dSlo2/KNa channels results in increased incidence and severity of induced seizure behavior, as well as the appearance of spontaneous seizure activity. Our results advance our understanding of neuronal excitability and protective mechanisms that preserve normal physiology and the suppression of seizure susceptibility.
Collapse
|
8
|
Abstract
Hypersynchronous neural activity is a characteristic feature of seizures. Although many Drosophila mutants of epilepsy-related genes display clear behavioral spasms and motor unit hyperexcitability, field potential measurements of aberrant hypersynchronous activity across brain regions during seizures have yet to be described. Here, we report a straightforward method to observe local field potentials (LFPs) from the Drosophila brain to monitor ensemble neural activity during seizures in behaving tethered flies. High frequency stimulation across the brain reliably triggers a stereotypic sequence of electroconvulsive seizure (ECS) spike discharges readily detectable in the dorsal longitudinal muscle (DLM) and coupled with behavioral spasms. During seizure episodes, the LFP signal displayed characteristic large-amplitude oscillations with a stereotypic temporal correlation to DLM flight muscle spiking. ECS-related LFP events were clearly distinct from rest- and flight-associated LFP patterns. We further characterized the LFP activity during different types of seizures originating from genetic and pharmacological manipulations. In the 'bang-sensitive' sodium channel mutant bangsenseless (bss), the LFP pattern was prolonged, and the temporal correlation between LFP oscillations and DLM discharges was altered. Following administration of the pro-convulsant GABAA blocker picrotoxin, we uncovered a qualitatively different LFP activity pattern, which consisted of a slow (1-Hz), repetitive, waveform, closely coupled with DLM bursting and behavioral spasms. Our approach to record brain LFPs presents an initial framework for electrophysiological analysis of the complex brain-wide activity patterns in the large collection of Drosophila excitability mutants.
Collapse
Affiliation(s)
- Atulya Iyengar
- Department of Biology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| | - Chun-Fang Wu
- Department of Biology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| |
Collapse
|
9
|
Characterization of Seizure Induction Methods in Drosophila. eNeuro 2021; 8:ENEURO.0079-21.2021. [PMID: 34330816 PMCID: PMC8387149 DOI: 10.1523/eneuro.0079-21.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/02/2021] [Accepted: 06/10/2021] [Indexed: 02/07/2023] Open
Abstract
Epilepsy is one of the most common neurologic disorders. Around one third of patients do not respond to current medications. This lack of treatment indicates a need for better understanding of the underlying mechanisms and, importantly, the identification of novel targets for drug manipulation. The fruit fly Drosophila melanogaster has a fast reproduction time, powerful genetics, and facilitates large sample sizes, making it a strong model of seizure mechanisms. To better understand behavioral and physiological phenotypes across major fly seizure genotypes we systematically measured seizure severity and secondary behavioral phenotypes at both the larval and adult stage. Comparison of several seizure-induction methods; specifically electrical, mechanical and heat induction, show that larval electroshock is the most effective at inducing seizures across a wide range of seizure-prone mutants tested. Locomotion in adults and larvae was found to be non-predictive of seizure susceptibility. Recording activity in identified larval motor neurons revealed variations in action potential (AP) patterns, across different genotypes, but these patterns did not correlate with seizure susceptibility. To conclude, while there is wide variation in mechanical induction, heat induction, and secondary phenotypes, electroshock is the most consistent method of seizure induction across known major seizure genotypes in Drosophila.
Collapse
|
10
|
Kasuya J, Iyengar A, Chen HL, Lansdon P, Wu CF, Kitamoto T. Milk-whey diet substantially suppresses seizure-like phenotypes of paraShu, a Drosophila voltage-gated sodium channel mutant. J Neurogenet 2019; 33:164-178. [PMID: 31096839 DOI: 10.1080/01677063.2019.1597082] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The Drosophila mutant paraShu harbors a dominant, gain-of-function allele of the voltage-gated sodium channel gene, paralytic (para). The mutant flies display severe seizure-like phenotypes, including neuronal hyperexcitability, spontaneous spasms, ether-induced leg shaking, and heat-induced convulsions. We unexpectedly found that two distinct food recipes used routinely in the Drosophila research community result in a striking difference in severity of the paraShu phenotypes. Namely, when paraShu mutants were raised on the diet originally formulated by Edward Lewis in 1960, they showed severe neurological defects as previously reported. In contrast, when they were raised on the diet developed by Frankel and Brousseau in 1968, these phenotypes were substantially suppressed. Comparison of the effects of these two well-established food recipes revealed that the diet-dependent phenotypic suppression is accounted for by milk whey, which is present only in the latter. Inclusion of milk whey in the diet during larval stages was critical for suppression of the adult paraShu phenotypes, suggesting that this dietary modification affects development of the nervous system. We also found that milk whey has selective effects on other neurological mutants. Among the behavioral phenotypes of different para mutant alleles, those of paraGEFS+ and parabss were suppressed by milk whey, while those of paraDS and parats1 were not significantly affected. Overall, our study demonstrates that different diets routinely used in Drosophila labs could have considerably different effects on neurological phenotypes of Drosophila mutants. This finding provides a solid foundation for further investigation into how dietary modifications affect development and function of the nervous system and, ultimately, how they influence behavior.
Collapse
Affiliation(s)
- Junko Kasuya
- a Department of Anesthesia, Carver College of Medicine , University of Iowa , Iowa city , IA , USA
| | - Atulya Iyengar
- b Department of Biology, College of Liberal Arts and Sciences , University of Iowa , Iowa city , IA , USA.,c Interdisciplinary Graduate Program in Neuroscience , University of Iowa , Iowa city , IA , USA
| | - Hung-Lin Chen
- d Department of Medical Research , Tung's Taichung MetroHarbor Hospital , Taichung , Taiwan 43503 , ROC
| | - Patrick Lansdon
- e Interdisciplinary Graduate Program in Genetics , University of Iowa , Iowa city , IA , USA
| | - Chun-Fang Wu
- b Department of Biology, College of Liberal Arts and Sciences , University of Iowa , Iowa city , IA , USA.,c Interdisciplinary Graduate Program in Neuroscience , University of Iowa , Iowa city , IA , USA.,e Interdisciplinary Graduate Program in Genetics , University of Iowa , Iowa city , IA , USA
| | - Toshihiro Kitamoto
- a Department of Anesthesia, Carver College of Medicine , University of Iowa , Iowa city , IA , USA.,c Interdisciplinary Graduate Program in Neuroscience , University of Iowa , Iowa city , IA , USA.,e Interdisciplinary Graduate Program in Genetics , University of Iowa , Iowa city , IA , USA
| |
Collapse
|
11
|
Reynolds ER. Shortened Lifespan and Other Age-Related Defects in Bang Sensitive Mutants of Drosophila melanogaster. G3 (BETHESDA, MD.) 2018; 8:3953-3960. [PMID: 30355763 PMCID: PMC6288826 DOI: 10.1534/g3.118.200610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/18/2018] [Indexed: 11/28/2022]
Abstract
Mitochondrial diseases are complex disorders that exhibit their primary effects in energetically active tissues. Damage generated by mitochondria is also thought to be a key component of aging and age-related disease. An important model for mitochondrial dysfunction is the bang sensitive (bs) mutants in Drosophila melanogaster Although these mutants all show a striking seizure phenotype, several bs mutants have gene products that are involved with mitochondrial function, while others affect excitability another way. All of the bs mutants (parabss , eas, jus, ses B, tko are examined here) paralyze and seize upon challenge with a sensory stimulus, most notably mechanical stimulation. These and other excitability mutants have been linked to neurodegeneration with age. In addition to these phenotypes, we have found age-related defects for several of the bs strains. The mutants eas, ses B, and tko display shortened lifespan, an increased mean recovery time from seizure with age, and decreased climbing ability over lifespan as compared to isogenic CS or w1118 lines. Other mutants show a subset of these defects. The age-related phenotypes can be rescued by feeding melatonin, an antioxidant, in all the mutants except ses B The age-related defects do not appear to be correlated with the seizure phenotype. Inducing seizures on a daily basis did not exacerbate the phenotypes and treatment with antiepileptic drugs did not increase lifespan. The results suggest that the excitability phenotypes and the age-related phenotypes may be somewhat independent and that these phenotypes mutants may arise from impacts on different pathways.
Collapse
|
12
|
Dean D, Weinstein H, Amin S, Karno B, McAvoy E, Hoy R, Recknagel A, Jarvis C, Deitcher D. Extending julius seizure, a bang-sensitive gene, as a model for studying epileptogenesis: Cold shock, and a new insertional mutation. Fly (Austin) 2017; 12:55-61. [PMID: 29125376 DOI: 10.1080/19336934.2017.1402993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The bang-sensitive (BS) mutants of Drosophila are an important model for studying epilepsy. We recently identified a novel BS locus, julius seizure (jus), encoding a protein containing two transmembrane domains and an extracellular cysteine-rich loop. We also determined that jussda iso7.8, a previously identified BS mutation, is an allele of jus by recombination, deficiency mapping, complementation testing, and genetic rescue. RNAi knockdown revealed that jus expression is important in cholinergic neurons and that the critical stage of jus expression is the mid-pupa. Finally, we found that a functional, GFP-tagged genomic construct of jus is expressed mostly in axons of the neck connectives and of the thoracic abdominal ganglia. In this Extra View article, we show that a MiMiC GFP-tagged Jus is localized to the same nervous system regions as the GFP-tagged genomic construct, but its expression is mostly confined to cell bodies and it causes bang-sensitivity. The MiMiC GFP-tag lies in the extracellular loop while the genomic construct is tagged at the C-terminus. This suggests that the alternate position of the GFP tag may disrupt Jus protein function by altering its subcellular localization and/or stability. We also show that a small subset of jus-expressing neurons are responsible for the BS phenotype. Finally, extending the utility of the BS seizure model, we show that jus mutants exhibit cold-sensitive paralysis and are partially sensitive to strobe-induced seizures.
Collapse
Affiliation(s)
- Derek Dean
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Hannah Weinstein
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Seema Amin
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Breelyn Karno
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Emma McAvoy
- a Department of Biology , Williams College , Williamstown , MA USA
| | - Ronald Hoy
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
| | - Andrew Recknagel
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
| | - Casey Jarvis
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
| | - David Deitcher
- b Department of Neurobiology and Behavior , Cornell University , Ithaca , NY USA
| |
Collapse
|