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Sokolowski DJ, Vasquez OE, Wilson MD, Sokolowski MB, Anreiter I. Transcriptomic effects of the foraging gene shed light on pathways of pleiotropy and plasticity. Ann N Y Acad Sci 2023; 1526:99-113. [PMID: 37350250 DOI: 10.1111/nyas.15015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Genes are often pleiotropic and plastic in their expression, features which increase and diversify the functionality of the genome. The foraging (for) gene in Drosophila melanogaster is highly pleiotropic and a long-standing model for studying individual differences in behavior and plasticity from ethological, evolutionary, and genetic perspectives. Its pleiotropy is known to be linked to its complex molecular structure; however, the downstream pathways and interactors remain mostly elusive. To uncover these pathways and interactors and gain a better understanding of how pleiotropy and plasticity are achieved at the molecular level, we explore the effects of different for alleles on gene expression at baseline and in response to 4 h of food deprivation, using RNA sequencing analysis in different Drosophila larval tissues. The results show tissue-specific transcriptomic dynamics influenced by for allelic variation and food deprivation, as well as genotype by treatment interactions. Differentially expressed genes yielded pathways linked to previously described for phenotypes and several potentially novel phenotypes. Together, these findings provide putative genes and pathways through which for might regulate its varied phenotypes in a pleiotropic, plastic, and gene-structure-dependent manner.
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Affiliation(s)
- Dustin J Sokolowski
- Genetics and Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Oscar E Vasquez
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Michael D Wilson
- Genetics and Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Program in Child and Brain Development, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | - Ina Anreiter
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
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2
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Vasquez OE, Allen AM, So AKC, Nguyen QH, Krause HM, Levine JD, Sokolowski MB. Characterizing the Protein Isoforms of foraging ( for), the PKGI Ortholog in Drosophila melanogaster. Int J Mol Sci 2023; 24:10219. [PMID: 37373366 DOI: 10.3390/ijms241210219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
The foraging (for) gene of Drosophila melanogaster encodes a cGMP-dependent protein kinase (PKG), which is a major effector of the cGMP signaling pathway involved in the regulation of behaviour and metabolic traits. Despite being well studied at the transcript level, little is known about the for gene at the protein level. Here, we provide a detailed characterization of the for gene protein (FOR) products and present new tools for their study, including five isoform-specific antibodies and a transgenic strain that carries an HA-labelled for allele (forBAC::HA). Our results showed that multiple FOR isoforms were expressed in the larval and adult stages of D. melanogaster and that the majority of whole-body FOR expression arises from three (P1, P1α, and P3) of eight putative protein isoforms. We found that FOR expression differed between the larval and adult stages and between the dissected larval organs we analyzed, which included the central nervous system (CNS), fat body, carcass, and intestine. Moreover, we showed that the FOR expression differed between two allelic variants of the for gene, namely, fors (sitter) and forR (rover), that are known to differ in many food-related traits. Together, our in vivo identification of FOR isoforms and the existence of temporal, spatial, and genetic differences in their expression lay the groundwork for determining their functional significance.
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Affiliation(s)
- Oscar E Vasquez
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Aaron M Allen
- Centre for Neural Circuits and Behaviour, Oxford University, Oxford OX1 3SR, UK
| | - Anthony K-C So
- Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Quynh H Nguyen
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Henry M Krause
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Joel D Levine
- Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada
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3
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Nevoa JC, Latorre-Estivalis JM, Pais FSM, Marliére NP, Fernandes GDR, Lorenzo MG, Guarneri AA. Global characterization of gene expression in the brain of starved immature Rhodnius prolixus. PLoS One 2023; 18:e0282490. [PMID: 36867641 PMCID: PMC9983911 DOI: 10.1371/journal.pone.0282490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 02/15/2023] [Indexed: 03/04/2023] Open
Abstract
BACKGROUND Rhodnius prolixus is a vector of Chagas disease and has become a model organism to study physiology, behavior, and pathogen interaction. The publication of its genome allowed initiating a process of comparative characterization of the gene expression profiles of diverse organs exposed to varying conditions. Brain processes control the expression of behavior and, as such, mediate immediate adjustment to a changing environment, allowing organisms to maximize their chances to survive and reproduce. The expression of fundamental behavioral processes like feeding requires fine control in triatomines because they obtain their blood meals from potential predators. Therefore, the characterization of gene expression profiles of key components modulating behavior in brain processes, like those of neuropeptide precursors and their receptors, seems fundamental. Here we study global gene expression profiles in the brain of starved R. prolixus fifth instar nymphs by means of RNA sequencing (RNA-Seq). RESULTS The expression of neuromodulatory genes such as those of precursors of neuropeptides, neurohormones, and their receptors; as well as the enzymes involved in the biosynthesis and processing of neuropeptides and biogenic amines were fully characterized. Other important gene targets such as neurotransmitter receptors, nuclear receptors, clock genes, sensory receptors, and takeouts genes were identified and their gene expression analyzed. CONCLUSION We propose that the set of neuromodulatory-related genes highly expressed in the brain of starved R. prolixus nymphs deserves functional characterization to allow the subsequent development of tools targeting them for bug control. As the brain is a complex structure that presents functionally specialized areas, future studies should focus on characterizing gene expression profiles in target areas, e.g. mushroom bodies, to complement our current knowledge.
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Affiliation(s)
- Jessica Coraiola Nevoa
- Vector Behaviour and Pathogen Interaction Group, Instituto René Rachou – FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Jose Manuel Latorre-Estivalis
- Laboratorio de Insectos Sociales, Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires - CONICET, Buenos Aires, Argentina
| | | | - Newmar Pinto Marliére
- Vector Behaviour and Pathogen Interaction Group, Instituto René Rachou – FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | | | - Marcelo Gustavo Lorenzo
- Vector Behaviour and Pathogen Interaction Group, Instituto René Rachou – FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Alessandra Aparecida Guarneri
- Vector Behaviour and Pathogen Interaction Group, Instituto René Rachou – FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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4
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Gallot A, Desouhant E, Lhuillier V, Lepetit D, El Filali A, Mouton L, Vieira-Heddi C, Amat I. The for gene as one of the drivers of foraging variations in a parasitic wasp. Mol Ecol 2022; 32:1760-1776. [PMID: 36571434 DOI: 10.1111/mec.16834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/08/2022] [Accepted: 12/22/2022] [Indexed: 12/27/2022]
Abstract
Foraging behaviours encompass strategies to locate resources and to exploit them. In many taxa, these behaviours are driven by a major gene called for, but the mechanisms of gene regulation vary between species. In the parasitoid wasp Venturia canescens, sexual and asexual populations coexist in sympatry but differ in life-history traits, physiology and behaviours, which could impact their foraging strategies. Here, we explored the molecular bases underpinning divergence in behaviours by testing two mutually nonexclusive hypotheses: first, the divergence in the for gene correlates with differences in foraging strategies, and second, the latter rely on a divergence in whole-genome expression. Using comparative genomics, we showed that the for gene was conserved across insects considering both sequence and gene model complexity. Polymorphism analysis did not support the occurrence of two allelic variants diverging across the two populations, yet the asexual population exhibited less polymorphism than the sexual population. Sexual and asexual transcriptomes split sharply, with 10.9% differentially expressed genes, but these were not enriched in behaviour-related genes. We showed that the for gene was more highly expressed in asexual female heads than in sexual heads and that those differences correlate with divergence in foraging behaviours in our experiment given that asexuals explored the environment more and exploited more host patches. Overall, these results suggested that fine tuning of for gene expression between populations may have led to distinct foraging behaviours. We hypothesized that reproductive polymorphism and coexistence in sympatry of sexual and asexual populations specialized to different ecological niches via divergent optima on phenotypic traits could imply adaptation through different expression patterns of the for gene and at many other loci throughout the genome.
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Affiliation(s)
- Aurore Gallot
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Emmanuel Desouhant
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Vincent Lhuillier
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - David Lepetit
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Adil El Filali
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Laurence Mouton
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Cristina Vieira-Heddi
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Isabelle Amat
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
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Xu H, Yu Y, Gao Y, Hassan A, Jia B, Huang Q. The cGMP-dependent protein kinase gene can regulate trail-following behaviour and locomotion in the termite Reticulitermes chinensis Snyder. INSECT MOLECULAR BIOLOGY 2022; 31:585-592. [PMID: 35506165 DOI: 10.1111/imb.12781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/28/2022] [Indexed: 06/14/2023]
Abstract
Social behaviours in termites are closely related to the chemical communication between individuals. It is well known that foraging worker termites can use trail pheromones to orient and locomote along trails so as to take food resources back to the nest. However, it is still unclear how termites recognize trail pheromones. Here, we cloned and sequenced the cGMP-dependent protein kinase (PKG) gene from the termite Reticulitermes chinensis Snyder, and then examined the response of termites to trail pheromones after silencing PKG through RNA interference. We found that PKG knockdown impaired termite ability to follow trail pheromones accurately and exhibited irregular behavioural trajectories in response to the trail pheromone in the termite R. chinensis. Our locomotion assays further showed that PKG knockdown significantly increased the turn angle and angular velocity in the termite R. chinensis. These findings help us better understanding the molecular regulatory mechanism of foraging communications in termites.
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Affiliation(s)
- Huan Xu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yichun Yu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yongyong Gao
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Ali Hassan
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Bao Jia
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China
- Nanning Institute of Termite Control, Nanning, Guangxi, China
| | - Qiuying Huang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China
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6
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Mueller JM, Zhang N, Carlson JM, Simpson JH. Variation and Variability in Drosophila Grooming Behavior. Front Behav Neurosci 2022; 15:769372. [PMID: 35087385 PMCID: PMC8787196 DOI: 10.3389/fnbeh.2021.769372] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/13/2021] [Indexed: 01/23/2023] Open
Abstract
Behavioral differences can be observed between species or populations (variation) or between individuals in a genetically similar population (variability). Here, we investigate genetic differences as a possible source of variation and variability in Drosophila grooming. Grooming confers survival and social benefits. Grooming features of five Drosophila species exposed to a dust irritant were analyzed. Aspects of grooming behavior, such as anterior to posterior progression, were conserved between and within species. However, significant differences in activity levels, proportion of time spent in different cleaning movements, and grooming syntax were identified between species. All species tested showed individual variability in the order and duration of action sequences. Genetic diversity was not found to correlate with grooming variability within a species: melanogaster flies bred to increase or decrease genetic heterogeneity exhibited similar variability in grooming syntax. Individual flies observed on consecutive days also showed grooming sequence variability. Standardization of sensory input using optogenetics reduced but did not eliminate this variability. In aggregate, these data suggest that sequence variability may be a conserved feature of grooming behavior itself. These results also demonstrate that large genetic differences result in distinguishable grooming phenotypes (variation), but that genetic heterogeneity within a population does not necessarily correspond to an increase in the range of grooming behavior (variability).
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Affiliation(s)
- Joshua M. Mueller
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara, Santa Barbara, CA, United States
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Neil Zhang
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Jean M. Carlson
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Julie H. Simpson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
- *Correspondence: Julie H. Simpson,
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7
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Devineni AV, Scaplen KM. Neural Circuits Underlying Behavioral Flexibility: Insights From Drosophila. Front Behav Neurosci 2022; 15:821680. [PMID: 35069145 PMCID: PMC8770416 DOI: 10.3389/fnbeh.2021.821680] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022] Open
Abstract
Behavioral flexibility is critical to survival. Animals must adapt their behavioral responses based on changes in the environmental context, internal state, or experience. Studies in Drosophila melanogaster have provided insight into the neural circuit mechanisms underlying behavioral flexibility. Here we discuss how Drosophila behavior is modulated by internal and behavioral state, environmental context, and learning. We describe general principles of neural circuit organization and modulation that underlie behavioral flexibility, principles that are likely to extend to other species.
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Affiliation(s)
- Anita V. Devineni
- Department of Biology, Emory University, Atlanta, GA, United States
- Zuckerman Mind Brain Institute, Columbia University, New York, NY, United States
| | - Kristin M. Scaplen
- Department of Psychology, Bryant University, Smithfield, RI, United States
- Center for Health and Behavioral Studies, Bryant University, Smithfield, RI, United States
- Department of Neuroscience, Brown University, Providence, RI, United States
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8
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Awde DN, Skandalis A, Richards MH. Foraging gene expression patterns in queens, workers, and males in a eusocial insect. CAN J ZOOL 2022. [DOI: 10.1139/cjz-2021-0124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reproductive division of labour is based on biased expression of complementary parental behaviours, brood production (egg-laying) by queens and brood care (in particular, brood-provisioning) by workers. In many social insect species, queens provision brood when establishing colonies at the beginning of a breeding season and reproductive division of labour begins with the emergence of workers. In many social insect species, the expression of foraging (for) mRNA is associated with the intensity of foraging behaviour and therefore brood-provisioning. However, only two studies have compared queen and worker for expression levels and neither accounted for transcript splice variation. In this study, we compare the expression level of the for-α transcript variant across four life stages of the queen caste, two behavioural groups of workers, and males of a eusocial sweat bee Lasioglossum laevissimum (Smith, 1853). Foundresses collected prior to the onset of the foraging season and males had the highest for-α expression levels. All active (post-hibernatory) queens and workers had similar for-α expression levels independent of behaviour. These results suggest that the for gene in L. laevissimum acts as a primer before foraging activity and that caste-specific expression patterns correlate with the timing of foraging activity in queens and workers.
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Affiliation(s)
- David N. Awde
- Department of Entomology, University of Kentucky, Lexington, KY 40546-0091, USA
| | - Adonis Skandalis
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Miriam H. Richards
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
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9
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Hughson BN. PKG acts in the adult corpora cardiaca to regulate nutrient stress-responsivity through adipokinetic hormone. JOURNAL OF INSECT PHYSIOLOGY 2022; 136:104339. [PMID: 34856210 DOI: 10.1016/j.jinsphys.2021.104339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 11/22/2021] [Accepted: 11/22/2021] [Indexed: 06/13/2023]
Abstract
In Drosophila melanogaster, the adipokinetic hormone (AKH) is a glucagon-like peptide that acts antagonistically with insulin-like peptides to maintain metabolic homeostasis. AKH is biosynthesized in and secreted from the corpora cardiaca (CC). This report describes a CC-specific role for dg2 - which encodes a cGMP-dependent protein kinase (PKG) - as a regulator of AKH during adulthood. Transcriptional silencing of dg2 during adulthood decreased starvation resistance, increased sucrose responsiveness, and decreased whole body lipid content. PKG protein was localized to CC cell membranes, and starvation caused a significant decrease in CC intracellular AKH content. Strikingly, reduced CC-dg2 expression caused a significant decrease in intracellular AKH content in adults fed ad libitum. This work demonstrated that dysregulation of CC-specific dg2 expression during adult life impaired metabolic homeostasis, and that dg2 acted in the CC to regulate systemic AKH activity.
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Affiliation(s)
- Bryon N Hughson
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, Canada; University of Toronto, 27 King's College Circle, Toronto, Ontario M5S 3B2, Canada.
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10
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Jezovit JA, Alwash N, Levine JD. Using Flies to Understand Social Networks. Front Neural Circuits 2021; 15:755093. [PMID: 34924963 PMCID: PMC8683092 DOI: 10.3389/fncir.2021.755093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/08/2021] [Indexed: 12/21/2022] Open
Abstract
Many animals live in groups and interact with each other, creating an organized collective structure. Social network analysis (SNA) is a statistical tool that aids in revealing and understanding the organized patterns of shared social connections between individuals in groups. Surprisingly, the application of SNA revealed that Drosophila melanogaster, previously considered a solitary organism, displays group dynamics and that the structure of group life is inherited. Although the number of studies investigating Drosophila social networks is currently limited, they address a wide array of questions that have only begun to capture the details of group level behavior in this insect. Here, we aim to review these studies, comparing their respective scopes and the methods used, to draw parallels between them and the broader body of knowledge available. For example, we highlight how despite methodological differences, there are similarities across studies investigating the effects of social isolation on social network dynamics. Finally, this review aims to generate hypotheses and predictions that inspire future research in the emerging field of Drosophila social networks.
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Affiliation(s)
- Jacob A. Jezovit
- Department of Cell and Systems Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Nawar Alwash
- Department of Cell and Systems Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Joel D. Levine
- Department of Cell and Systems Biology, University of Toronto Mississauga, Mississauga, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- International Research Centre for Neurointelligence, University of Tokyo, Tokyo, Japan
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11
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Dason JS, Anreiter I, Wu CF. Transcending boundaries: from quantitative genetics to single genes. J Neurogenet 2021; 35:95-98. [PMID: 34544325 DOI: 10.1080/01677063.2021.1960519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Jeffrey S Dason
- Department of Biomedical Sciences, University of Windsor, Windsor, Canada
| | - Ina Anreiter
- Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Chun-Fang Wu
- Department of Biology, University of Iowa, Iowa City, IA, USA
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12
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Allen AM, B Sokolowski M. Expression of the foraging gene in adult Drosophila melanogaster. J Neurogenet 2021; 35:192-212. [PMID: 34382904 PMCID: PMC8846931 DOI: 10.1080/01677063.2021.1941946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The foraging gene in Drosophila melanogaster, which encodes a cGMP-dependent protein kinase, is a highly conserved, complex gene with multiple pleiotropic behavioral and physiological functions in both the larval and adult fly. Adult foraging expression is less well characterized than in the larva. We characterized foraging expression in the brain, gastric system, and reproductive systems using a T2A-Gal4 gene-trap allele. In the brain, foraging expression appears to be restricted to multiple sub-types of glia. This glial-specific cellular localization of foraging was supported by single-cell transcriptomic atlases of the adult brain. foraging is extensively expressed in most cell types in the gastric and reproductive systems. We then mapped multiple cis-regulatory elements responsible for parts of the observed expression patterns by a nested cloned promoter-Gal4 analysis. The mapped cis-regulatory elements were consistently modular when comparing the larval and adult expression patterns. These new data using the T2A-Gal4 gene-trap and cloned foraging promoter fusion GAL4's are discussed with respect to previous work using an anti-FOR antibody, which we show here to be non-specific. Future studies of foraging's function will consider roles for glial subtypes and peripheral tissues (gastric and reproductive systems) in foraging's pleiotropic behavioral and physiological effects.
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Affiliation(s)
- Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Marla B Sokolowski
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
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13
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Murakami K, Palermo J, Stanhope BA, Gibbs AG, Keene AC. A screen for sleep and starvation resistance identifies a wake-promoting role for the auxiliary channel unc79. G3 (BETHESDA, MD.) 2021; 11:6300522. [PMID: 34849820 PMCID: PMC8496288 DOI: 10.1093/g3journal/jkab199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/25/2021] [Indexed: 11/22/2022]
Abstract
The regulation of sleep and metabolism are highly interconnected, and dysregulation of sleep is linked to metabolic diseases that include obesity, diabetes, and heart disease. Furthermore, both acute and long-term changes in diet potently impact sleep duration and quality. To identify novel factors that modulate interactions between sleep and metabolic state, we performed a genetic screen for their roles in regulating sleep duration, starvation resistance, and starvation-dependent modulation of sleep. This screen identified a number of genes with potential roles in regulating sleep, metabolism, or both processes. One such gene encodes the auxiliary ion channel UNC79, which was implicated in both the regulation of sleep and starvation resistance. Genetic knockdown or mutation of unc79 results in flies with increased sleep duration, as well as increased starvation resistance. Previous findings have shown that unc79 is required in pacemaker for 24-hours circadian rhythms. Here, we find that unc79 functions in the mushroom body, but not pacemaker neurons, to regulate sleep duration and starvation resistance. Together, these findings reveal spatially localized separable functions of unc79 in the regulation of circadian behavior, sleep, and metabolic function.
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Affiliation(s)
- Kazuma Murakami
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Justin Palermo
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Bethany A Stanhope
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Allen G Gibbs
- Department of Biological Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154, USA
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
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14
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Hofmann F. The cGMP system: components and function. Biol Chem 2021; 401:447-469. [PMID: 31747372 DOI: 10.1515/hsz-2019-0386] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 10/30/2019] [Indexed: 12/29/2022]
Abstract
The cyclic guanosine monophosphate (cGMP) signaling system is one of the most prominent regulators of a variety of physiological and pathophysiological processes in many mammalian and non-mammalian tissues. Targeting this pathway by increasing cGMP levels has been a very successful approach in pharmacology as shown for nitrates, phosphodiesterase (PDE) inhibitors and stimulators of nitric oxide-guanylyl cyclase (NO-GC) and particulate GC (pGC). This is an introductory review to the cGMP signaling system intended to introduce those readers to this system, who do not work in this area. This article does not intend an in-depth review of this system. Signal transduction by cGMP is controlled by the generating enzymes GCs, the degrading enzymes PDEs and the cGMP-regulated enzymes cyclic nucleotide-gated ion channels, cGMP-dependent protein kinases and cGMP-regulated PDEs. Part A gives a very concise introduction to the components. Part B gives a very concise introduction to the functions modulated by cGMP. The article cites many recent reviews for those who want a deeper insight.
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Affiliation(s)
- Franz Hofmann
- Pharmakologisches Institut, Technische Universität München, Biedersteiner Str. 29, D-80802 München, Germany
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15
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Reiss AP, Rankin CH. Gaining an understanding of behavioral genetics through studies of foraging in Drosophila and learning in C. elegans. J Neurogenet 2021; 35:119-131. [PMID: 34151727 DOI: 10.1080/01677063.2021.1928113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The pursuit of understanding behavior has led to investigations of how genes, the environment, and the nervous system all work together to produce and influence behavior, giving rise to a field of research known as behavioral neurogenetics. This review focuses on the research journeys of two pioneers of aspects of behavioral neurogenetic research: Dr. Marla Sokolowski and Dr. Catharine Rankin as examples of how different approaches have been used to understand relationships between genes and behavior. Marla Sokolowski's research is centered around the discovery and analysis of foraging, a gene responsible for the natural behavioral polymorphism of Drosophila melanogaster larvae foraging behavior. Catharine Rankin's work began with demonstrating the ability to learn in Caenorhabditis elegans and then setting out to investigate the mechanisms underlying the "simplest" form of learning, habituation. Using these simple invertebrate organisms both investigators were able to perform in-depth dissections of behavior at genetic and molecular levels. By exploring their research and highlighting their findings we present ways their work has furthered our understanding of behavior and contributed to the field of behavioral neurogenetics.
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Affiliation(s)
- Aaron P Reiss
- Department of Psychology, University of British Columbia, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Catharine H Rankin
- Department of Psychology, University of British Columbia, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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16
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Greenspan RJ. Learning about quantitative genetics from Marla Sokolowski. J Neurogenet 2021; 35:110-111. [PMID: 34128769 DOI: 10.1080/01677063.2021.1940167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Marla Sokolowski is a true pioneer in behavioral genetics, having made the first molecular delineation of a naturally occurring behavioral polymorphism in her work on the foraging locus in Drosophila melanogaster. The gene was subsequently found to be responsible for behavioral variants and types in many other species, both invertebrate and mammal (human). The path to get there is a paradigmatic example of how to use the power of genetic analysis, including some rather esoteric techniques, to zero in on a gene and delineate its molecular identity and its pleiotropic roles.
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Affiliation(s)
- Ralph J Greenspan
- Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA, USA
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17
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Alwash N, Allen AM, B Sokolowski M, Levine JD. The Drosophila melanogaster foraging gene affects social networks. J Neurogenet 2021; 35:249-261. [PMID: 34121597 DOI: 10.1080/01677063.2021.1936517] [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] [Indexed: 10/21/2022]
Abstract
Drosophila melanogaster displays social behaviors including courtship, mating, aggression, and group foraging. Recent studies employed social network analyses (SNAs) to show that D. melanogaster strains differ in their group behavior, suggesting that genes influence social network phenotypes. Aside from genes associated with sensory function, few studies address the genetic underpinnings of these networks. The foraging gene (for) is a well-established example of a pleiotropic gene that regulates multiple behavioral phenotypes and their plasticity. In D. melanogaster, there are two naturally occurring alleles of for called rover and sitter that differ in their larval and adult food-search behavior as well as other behavioral phenotypes. Here, we hypothesize that for affects behavioral elements required to form social networks and the social networks themselves. These effects are evident when we manipulate gene dosage. We found that flies of the rover and sitter strains exhibit differences in duration, frequency, and reciprocity of pairwise interactions, and they form social networks with differences in assortativity and global efficiency. Consistent with other adult phenotypes influenced by for, rover-sitter heterozygotes show intermediate patterns of dominance in many of these characteristics. Multiple generations of backcrossing a rover allele into a sitter strain showed that many but not all of these rover-sitter differences may be attributed to allelic variation at for. Our findings reveal the significant role that for plays in affecting social network properties and their behavioral elements in Drosophila melanogaster.
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Affiliation(s)
- Nawar Alwash
- Department of Biology, University of Toronto at Mississauga, Mississauga, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behavior, University of Oxford, Oxford, UK
| | - Marla B Sokolowski
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Canada
| | - Joel D Levine
- Department of Biology, University of Toronto at Mississauga, Mississauga, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Canada
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18
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Sokolowski DJ. Women in science: a son's perspective. J Neurogenet 2021; 35:104-106. [PMID: 34121599 DOI: 10.1080/01677063.2021.1940171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
I am often asked how our mother inspired my sister Moriah and me to want to become scientists. She never directly suggested we should go down that path. Instead, she shared the aspects of the natural world, that she loved, with us while keeping the non-science aspects of her job separate from our lives at home. Now, I have learned that her perspective provides insights that spark innovative discoveries, some of which challenged the status quo. Her passion for research has allowed her to pursue what she believes to be worth studying. Her personality and collaborative nature allow her to be teased at home, facilitate a room of diverse opinions, and command a hall of hundreds of people. Her respect for those around her is inspiring. My mom's trust in her trainees and collaborators allows her to answer questions that could fundamentally not be answered had she pigeonholed herself to a single field. She managed to accomplish everything while being nothing other than my mom to me, and I am so glad that I am growing into a person who can truly appreciate the woman she is to everyone else.
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Affiliation(s)
- Dustin J Sokolowski
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.,Genetics and Genome Biology, SickKids Research Institute, Toronto, ON, Canada
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19
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Oepen AS, Catalano JL, Azanchi R, Kaun KR. The foraging gene affects alcohol sensitivity, metabolism and memory in Drosophila. J Neurogenet 2021; 35:236-248. [PMID: 34092172 DOI: 10.1080/01677063.2021.1931178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The genetic basis of alcohol use disorder (AUD) is complex. Understanding how natural genetic variation contributes to alcohol phenotypes can help us identify and understand the genetic basis of AUD. Recently, a single nucleotide polymorphism in the human foraging (for) gene ortholog, Protein Kinase cGMP-Dependent 1 (PRKG1), was found to be associated with stress-induced risk for alcohol abuse. However, the mechanistic role that PRKG1 plays in AUD is not well understood. We use natural variation in the Drosophila for gene to describe how variation of cGMP-dependent protein kinase (PKG) activity modifies ethanol-induced phenotypes. We found that variation in for affects ethanol-induced increases in locomotion and memory of the appetitive properties of ethanol intoxication. Further, these differences may stem from the ability to metabolize ethanol. Together, this data suggests that natural variation in PKG modulates cue reactivity for alcohol, and thus could influence alcohol cravings by differentially modulating metabolic and behavioral sensitivities to alcohol.
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Affiliation(s)
- Anne S Oepen
- Department of Neuroscience, Brown University, Providence, RI, USA.,Masters Program in Developmental, Neuronal and Behavioral Biology, Georg-August-University, Göttingen, Germany
| | - Jamie L Catalano
- Department of Neuroscience, Brown University, Providence, RI, USA.,Molecular Pharmacology and Physiology Graduate Program, Brown University, Providence, RI, USA
| | - Reza Azanchi
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Karla R Kaun
- Department of Neuroscience, Brown University, Providence, RI, USA
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20
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Dason JS, Sokolowski MB. A cGMP-dependent protein kinase, encoded by the Drosophila foraging gene, regulates neurotransmission through changes in synaptic structure and function. J Neurogenet 2021; 35:213-220. [PMID: 33998378 DOI: 10.1080/01677063.2021.1905639] [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] [Indexed: 10/21/2022]
Abstract
A cGMP-dependent protein kinase (PKG) encoded by the Drosophila foraging (for) gene regulates both synaptic structure (nerve terminal growth) and function (neurotransmission) through independent mechanisms at the Drosophila larval neuromuscular junction (nmj). Glial for is known to restrict nerve terminal growth, whereas presynaptic for inhibits synaptic vesicle (SV) exocytosis during low frequency stimulation. Presynaptic for also facilitates SV endocytosis during high frequency stimulation. for's effects on neurotransmission can occur independent of any changes in nerve terminal growth. However, it remains unclear if for's effects on neurotransmission affect nerve terminal growth. Furthermore, it's possible that for's effects on synaptic structure contribute to changes in neurotransmission. In the present study, we examined these questions using RNA interference to selectively knockdown for in presynaptic neurons or glia at the Drosophila larval nmj. Consistent with our previous findings, presynaptic knockdown of for impaired SV endocytosis, whereas knockdown of glial for had no effect on SV endocytosis. Surprisingly, we found that knockdown of either presynaptic or glial for increased neurotransmitter release in response to low frequency stimulation. Knockdown of presynaptic for did not affect nerve terminal growth, demonstrating that for's effects on neurotransmission does not alter nerve terminal growth. In contrast, knockdown of glial for enhanced nerve terminal growth. This enhanced nerve terminal growth was likely the cause of the enhanced neurotransmitter release seen following knockdown of glial for. Overall, we show that for can affect neurotransmitter release by regulating both synaptic structure and function.
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Affiliation(s)
- Jeffrey S Dason
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada.,Department of Biomedical Sciences, University of Windsor, Windsor, Canada
| | - Marla B Sokolowski
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
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21
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Anreiter I, Allen AM, Vasquez OE, To L, Douglas SJ, Alvarez JV, Ewer J, Sokolowski MB. The Drosophila foraging gene plays a vital role at the start of metamorphosis for subsequent adult emergence. J Neurogenet 2021; 35:179-191. [PMID: 33944658 DOI: 10.1080/01677063.2021.1914608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The foraging (for) gene has been extensively studied in many species for its functions in development, physiology, and behavior. It is common for genes that influence behavior and development to be essential genes, and for has been found to be an essential gene in both fruit flies and mammals, with for mutants dying before reaching the adult stage. However, the biological process underlying the lethality associated with this gene is not known. Here, we show that in Drosophila melanogaster, some but not all gene products of for are essential for survival. Specifically, we show that promoter 3 of for, but not promoters 1, 2, and 4 are required for survival past pupal stage. We use full and partial genetic deletions of for, and temperature-restricted knock-down of the gene to further investigate the stage of lethality. While deletion analysis shows that flies lacking for die at the end of pupal development, as pharate adults, temperature-restricted knock-down shows that for is only required at the start of pupal development, for normal adult emergence (AE) and viability. We further show that the inability of these mutants to emerge from their pupal cases is linked to deficiencies in emergence behaviors, caused by a possible energy deficiency, and finally, that the lethality of for mutants seems to be linked to protein isoform P3, transcribed from for promoter 3.
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Affiliation(s)
- Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada.,Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behavior, University of Oxford, Oxford, UK
| | - Oscar E Vasquez
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Lydia To
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Scott J Douglas
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Javier V Alvarez
- Centro Interdisciplinario de Neurociencia de Valparaíso e Instituto de Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - John Ewer
- Centro Interdisciplinario de Neurociencia de Valparaíso e Instituto de Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
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22
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McKinney RM, Valdez R, Ben-Shahar Y. The genetic architecture of larval aggregation behavior in Drosophila. J Neurogenet 2021; 35:274-284. [PMID: 33629904 DOI: 10.1080/01677063.2021.1887174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Many insect species exhibit basal social behaviors such as aggregation, which play important roles in their feeding and mating ecologies. However, the evolutionary, genetic, and physiological mechanisms that regulate insect aggregation remain unknown for most species. Here, we used natural populations of Drosophila melanogaster to identify the genetic architecture that drives larval aggregation feeding behavior. By using quantitative and reverse genetic approaches, we have identified a complex neurogenetic network that plays a role in regulating the decision of larvae to feed in either solitude or as a group. Results from single gene, RNAi-knockdown experiments show that several of the identified genes represent key nodes in the genetic network that determines the level of aggregation while feeding. Furthermore, we show that a single non-coding variant in the gene CG14205, a putative acyltransferase, is associated with both decreased mRNA expression and increased aggregate formation, which suggests that it has a specific role in inhibiting aggregation behavior. Our results identify, for the first time, the genetic components which interact to regulate naturally occurring levels of aggregation in D. melanogaster larvae.
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Affiliation(s)
- Ross M McKinney
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Ryan Valdez
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Yehuda Ben-Shahar
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
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23
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Hughson BN, Shimell M, O'Connor MB. AKH Signaling in D. melanogaster Alters Larval Development in a Nutrient-Dependent Manner That Influences Adult Metabolism. Front Physiol 2021; 12:619219. [PMID: 33708137 PMCID: PMC7940354 DOI: 10.3389/fphys.2021.619219] [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: 10/19/2020] [Accepted: 01/11/2021] [Indexed: 12/21/2022] Open
Abstract
Metabolism, growth, and development are intrinsically linked, and their coordination is dependent upon inter-organ communication mediated by anabolic, catabolic, and steroid hormones. In Drosophila melanogaster, the corpora cardiaca (CC) influences metabolic homeostasis through adipokinetic hormone (AKH) signaling. AKH has glucagon-like properties and is evolutionarily conserved in mammals as the gonadotropin-releasing hormone, but its role in insect development is unknown. Here we report that AKH signaling alters larval development in a nutrient stress-dependent manner. This activity is regulated by the locus dg2, which encodes a cGMP-dependent protein kinase (PKG). CC-specific downregulation of dg2 expression delayed the developmental transition from larval to pupal life, and altered adult metabolism and behavior. These developmental effects were AKH-dependent, and were observed only in flies that experienced low nutrient stress during larval development. Calcium-mediated vesicle exocytosis regulates ecdysteroid secretion from the prothoracic gland (PG), and we found that AKH signaling increased cytosolic free calcium levels in the PG. We identified a novel pathway through which PKG acts in the CC to communicate metabolic information to the PG via AKH signaling. AKH signaling provides a means whereby larval nutrient stress can alter developmental trajectories into adulthood.
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Affiliation(s)
- Bryon N Hughson
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - MaryJane Shimell
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, United States
| | - Michael B O'Connor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, United States
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24
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Merchant A, Song D, Yang X, Li X, Zhou X“J. Candidate
foraging
gene orthologs in a lower termite,
Reticulitermes flavipes. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2020; 334:168-177. [DOI: 10.1002/jez.b.22918] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 08/24/2019] [Accepted: 09/14/2019] [Indexed: 11/07/2022]
Affiliation(s)
- Austin Merchant
- Department of EntomologyUniversity of KentuckyLexington Kentucky
| | - Dongyan Song
- Department of EntomologyUniversity of KentuckyLexington Kentucky
| | - Xiaowei Yang
- Department of EntomologyUniversity of KentuckyLexington Kentucky
| | - Xiangrui Li
- Department of EntomologyUniversity of KentuckyLexington Kentucky
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing China
| | - Xuguo “Joe” Zhou
- Department of EntomologyUniversity of KentuckyLexington Kentucky
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25
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Goossens S, Wybouw N, Van Leeuwen T, Bonte D. The physiology of movement. MOVEMENT ECOLOGY 2020; 8:5. [PMID: 32042434 PMCID: PMC7001223 DOI: 10.1186/s40462-020-0192-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 01/08/2020] [Indexed: 05/05/2023]
Abstract
Movement, from foraging to migration, is known to be under the influence of the environment. The translation of environmental cues to individual movement decision making is determined by an individual's internal state and anticipated to balance costs and benefits. General body condition, metabolic and hormonal physiology mechanistically underpin this internal state. These physiological determinants are tightly, and often genetically linked with each other and hence central to a mechanistic understanding of movement. We here synthesise the available evidence of the physiological drivers and signatures of movement and review (1) how physiological state as measured in its most coarse way by body condition correlates with movement decisions during foraging, migration and dispersal, (2) how hormonal changes underlie changes in these movement strategies and (3) how these can be linked to molecular pathways. We reveale that a high body condition facilitates the efficiency of routine foraging, dispersal and migration. Dispersal decision making is, however, in some cases stimulated by a decreased individual condition. Many of the biotic and abiotic stressors that induce movement initiate a physiological cascade in vertebrates through the production of stress hormones. Movement is therefore associated with hormone levels in vertebrates but also insects, often in interaction with factors related to body or social condition. The underlying molecular and physiological mechanisms are currently studied in few model species, and show -in congruence with our insights on the role of body condition- a central role of energy metabolism during glycolysis, and the coupling with timing processes during migration. Molecular insights into the physiological basis of movement remain, however, highly refractory. We finalise this review with a critical reflection on the importance of these physiological feedbacks for a better mechanistic understanding of movement and its effects on ecological dynamics at all levels of biological organization.
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Affiliation(s)
- Steven Goossens
- Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Nicky Wybouw
- Laboratory of Agrozoology, Department of Plants and Crops, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Thomas Van Leeuwen
- Laboratory of Agrozoology, Department of Plants and Crops, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Dries Bonte
- Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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26
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Abstract
The Drosophila melanogaster foraging (for) gene is a well-established example of a gene with major effects on behavior and natural variation. This gene is best known for underlying the behavioral strategies of rover and sitter foraging larvae, having been mapped and named for this phenotype. Nevertheless, in the last three decades an extensive array of studies describing for's role as a modifier of behavior in a wide range of phenotypes, in both Drosophila and other organisms, has emerged. Furthermore, recent work reveals new insights into the genetic and molecular underpinnings of how for affects these phenotypes. In this article, we discuss the history of the for gene and its role in natural variation in behavior, plasticity, and behavioral pleiotropy, with special attention to recent findings on the molecular structure and transcriptional regulation of this gene.
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Affiliation(s)
- Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada;
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada;
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27
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Drosophila melanogaster foraging regulates a nociceptive-like escape behavior through a developmentally plastic sensory circuit. Proc Natl Acad Sci U S A 2019; 117:23286-23291. [PMID: 31213548 DOI: 10.1073/pnas.1820840116] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Painful or threatening experiences trigger escape responses that are guided by nociceptive neuronal circuitry. Although some components of this circuitry are known and conserved across animals, how this circuitry is regulated at the genetic and developmental levels is mostly unknown. To escape noxious stimuli, such as parasitoid wasp attacks, Drosophila melanogaster larvae generate a curling and rolling response. Rover and sitter allelic variants of the Drosophila foraging (for) gene differ in parasitoid wasp susceptibility, suggesting a link between for and nociception. By optogenetically activating cells associated with each of for's promoters (pr1-pr4), we show that pr1 cells regulate larval escape behavior. In accordance with rover and sitter differences in parasitoid wasp susceptibility, we found that rovers have higher pr1 expression and increased sensitivity to nociception relative to sitters. The for null mutants display impaired responses to thermal nociception, which are rescued by restoring for expression in pr1 cells. Conversely, knockdown of for in pr1 cells phenocopies the for null mutant. To gain insight into the circuitry underlying this response, we used an intersectional approach and activity-dependent GFP reconstitution across synaptic partners (GRASP) to show that pr1 cells in the ventral nerve cord (VNC) are required for the nociceptive response, and that multidendritic sensory nociceptive neurons synapse onto pr1 neurons in the VNC. Finally, we show that activation of the pr1 circuit during development suppresses the escape response. Our data demonstrate a role of for in larval nociceptive behavior. This function is specific to for pr1 neurons in the VNC, guiding a developmentally plastic escape response circuit.
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28
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Abstract
Foraging is a goal-directed behavior that balances the need to explore the environment for resources with the need to exploit those resources. In Drosophila melanogaster, distinct phenotypes have been observed in relation to the foraging gene (for), labeled the rover and sitter. Adult rovers explore their environs more extensively than do adult sitters. We explored whether this distinction would be conserved in humans. We made use of a distinction from regulatory mode theory between those who "get on with it," so-called locomotors, and those who prefer to ensure they "do the right thing," so-called assessors. In this logic, rovers and locomotors share similarities in goal pursuit, as do sitters and assessors. We showed that genetic variation in PRKG1, the human ortholog of for, is associated with preferential adoption of a specific regulatory mode. Next, participants performed a foraging task to see whether genetic differences associated with distinct regulatory modes would be associated with distinct goal pursuit patterns. Assessors tended to hug the boundary of the foraging environment, much like behaviors seen in Drosophila adult sitters. In a patchy foraging environment, assessors adopted more cautious search strategies maximizing exploitation. These results show that distinct patterns of goal pursuit are associated with particular genotypes of PRKG1, the human ortholog of for.
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29
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Takahashi Y, Tanaka R, Yamamoto D, Noriyuki S, Kawata M. Balanced genetic diversity improves population fitness. Proc Biol Sci 2019; 285:rspb.2017.2045. [PMID: 29343595 DOI: 10.1098/rspb.2017.2045] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 12/18/2017] [Indexed: 11/12/2022] Open
Abstract
Although genetic diversity within a population is suggested to improve population-level fitness and productivity, the existence of these effects is controversial because empirical evidence for an ecological effect of genetic diversity and the underlying mechanisms is scarce and incomplete. Here, we show that the natural single-gene behavioural polymorphism (Rover and sitter) in Drosophila melanogaster has a positive effect on population fitness. Our simple numerical model predicted that the fitness of a polymorphic population would be higher than that expected with two monomorphic populations, but only under balancing selection. Moreover, this positive diversity effect of genetic polymorphism was attributable to a complementarity effect, rather than to a selection effect. Our empirical tests using the behavioural polymorphism in D. melanogaster clearly supported the model predictions. These results provide direct evidence for an ecological effect of genetic diversity on population fitness and its condition dependence.
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Affiliation(s)
- Yuma Takahashi
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Miyagi, Japan .,Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Ryoya Tanaka
- Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Daisuke Yamamoto
- Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
| | - Suzuki Noriyuki
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, USA.,Center for Geo-Environmental Science, Rissho University, Saitama, Japan
| | - Masakado Kawata
- Graduate School of Life Sciences, Tohoku University, Miyagi, Japan
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30
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Dason JS, Allen AM, Vasquez OE, Sokolowski MB. Distinct functions of a cGMP-dependent protein kinase in nerve terminal growth and synaptic vesicle cycling. J Cell Sci 2019; 132:jcs.227165. [DOI: 10.1242/jcs.227165] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/26/2019] [Indexed: 01/20/2023] Open
Abstract
Sustained neurotransmission requires the tight coupling of synaptic vesicle (SV) exocytosis and endocytosis. The mechanisms underlying this coupling are poorly understood. We tested the hypothesis that a cGMP-dependent protein kinase (PKG), encoded by the foraging (for) gene in Drosophila melanogaster, is critical for this process using a for null mutant, genomic rescues, and tissue specific rescues. We uncoupled FOR's exocytic and endocytic functions in neurotransmission using a temperature-sensitive shibire mutant in conjunction with fluorescein-assisted light inactivation of FOR. We discovered a dual role for presynaptic FOR, where FOR inhibits SV exocytosis during low frequency stimulation by negatively regulating presynaptic Ca2+ levels and maintains neurotransmission during high frequency stimulation by facilitating SV endocytosis. Additionally, glial FOR negatively regulated nerve terminal growth through TGF-β signaling and this developmental effect was independent from FOR's effects on neurotransmission. Overall, FOR plays a critical role in coupling SV exocytosis and endocytosis, thereby balancing these two components to maintain sustained neurotransmission.
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Affiliation(s)
- Jeffrey S. Dason
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Department of Biological Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada
| | - Aaron M. Allen
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Present Address: Centre for Neural Circuits and Behaviour, University of Oxford, OX1 3SR Oxford, UK
| | - Oscar E. Vasquez
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Marla B. Sokolowski
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, M5G 1M1, Canada
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Allen AM, Anreiter I, Vesterberg A, Douglas SJ, Sokolowski MB. Pleiotropy of the Drosophila melanogaster foraging gene on larval feeding-related traits. J Neurogenet 2018; 32:256-266. [PMID: 30303018 PMCID: PMC6309726 DOI: 10.1080/01677063.2018.1500572] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/09/2018] [Indexed: 10/28/2022]
Abstract
Little is known about the molecular underpinning of behavioral pleiotropy. The Drosophila melanogaster foraging gene is highly pleiotropic, affecting many independent larval and adult phenotypes. Included in foraging's multiple phenotypes are larval foraging path length, triglyceride levels, and food intake. foraging has a complex structure with four promoters and 21 transcripts that encode nine protein isoforms of a cGMP dependent protein kinase (PKG). We examined if foraging's complex molecular structure underlies the behavioral pleiotropy associated with this gene. Using a promotor analysis strategy, we cloned DNA fragments upstream of each of foraging's transcription start sites and generated four separate forpr-Gal4s. Supporting our hypothesis of modular function, they had discrete, restricted expression patterns throughout the larva. In the CNS, forpr1-Gal4 and forpr4-Gal4 were expressed in neurons while forpr2-Gal4 and forpr3-Gal4 were expressed in glia cells. In the gastric system, forpr1-Gal4 and forpr3-Gal4 were expressed in enteroendocrine cells of the midgut while forpr2-Gal4 was expressed in the stem cells of the midgut. forpr3-Gal4 was expressed in the midgut enterocytes, and midgut and hindgut visceral muscle. forpr4-Gal4's gastric system expression was restricted to the hindgut. We also found promoter specific expression in the larval fat body, salivary glands, and body muscle. The modularity of foraging's molecular structure was also apparent in the phenotypic rescues. We rescued larval path length, triglyceride levels (bordered on significance), and food intake of for0 null larvae using different forpr-Gal4s to drive UAS-forcDNA. In a foraging null genetic background, forpr1-Gal4 was the only promoter driven Gal4 to rescue larval path length, forpr3-Gal4 altered triglyceride levels, and forpr4-Gal4 rescued food intake. Our results refine the spatial expression responsible for foraging's associated phenotypes, as well as the sub-regions of the locus responsible for their expression. foraging's pleiotropy arises at least in part from the individual contributions of its four promoters.
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Affiliation(s)
- A. M. Allen
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada, M5S 3G5
- Current address: Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK, OX1 3SR
| | - I. Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada, M5S 3B2
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, West Tower, 661 University Ave., Suite 505, Toronto, Ontario, Canada, M5G 1M1
| | - A. Vesterberg
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada, M5S 3B2
| | - S. J. Douglas
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada, M5S 3G5
| | - M. B. Sokolowski
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada, M5S 3G5
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada, M5S 3B2
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, West Tower, 661 University Ave., Suite 505, Toronto, Ontario, Canada, M5G 1M1
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32
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Kelly SP, Risley MG, Miranda LE, Dawson-Scully K. Contribution of a natural polymorphism in protein kinase G modulates electroconvulsive seizure recovery in Drosophila melanogaster. ACTA ACUST UNITED AC 2018; 221:jeb.179747. [PMID: 29798846 DOI: 10.1242/jeb.179747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 05/21/2018] [Indexed: 11/20/2022]
Abstract
Drosophila melanogaster is a well-characterized model for neurological disorders and is widely used for investigating causes of altered neuronal excitability leading to seizure-like behavior. One method used to analyze behavioral output of neuronal perturbance is recording the time to locomotor recovery from an electroconvulsive shock. Based on this behavior, we sought to quantify seizure susceptibility in larval D. melanogaster with differences in the enzymatic activity levels of a major protein, cGMP-dependent protein kinase (PKG). PKG, encoded by foraging, has two natural allelic variants and has previously been implicated in several important physiological characteristics including: foraging patterns, learning and memory, and environmental stress tolerance. The well-established NO/cGMP/PKG signaling pathway found in the fly, which potentially targets downstream K+ channel(s), ultimately impacts membrane excitability, leading to our hypothesis: altering PKG enzymatic activity modulates time to recovery from an electroconvulsive seizure. Our results show that by both genetically and pharmacologically increasing PKG enzymatic activity, we can decrease the locomotor recovery time from an electroconvulsive seizure in larval D. melanogaster.
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Affiliation(s)
- Stephanie P Kelly
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA
| | - Monica G Risley
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA.,International Max-Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, FL 33431, USA
| | - Leonor E Miranda
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA
| | - Ken Dawson-Scully
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA
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Hughson BN, Anreiter I, Jackson Chornenki NL, Murphy KR, Ja WW, Huber R, Sokolowski MB. The adult foraging assay (AFA) detects strain and food-deprivation effects in feeding-related traits of Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2018; 106:20-29. [PMID: 28860037 PMCID: PMC5832525 DOI: 10.1016/j.jinsphys.2017.08.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 08/23/2017] [Accepted: 08/26/2017] [Indexed: 06/07/2023]
Abstract
We introduce a high-resolution adult foraging assay (AFA) that relates pre- and post-ingestive walking behavior to individual instances of food consumption. We explore the utility of the AFA by taking advantage of established rover and sitter strains known to differ in a number of feeding-related traits. The AFA allows us to effectively distinguish locomotor behavior in Fed and Food-Deprived (FD) rover and sitter foragers. We found that rovers exhibit more exploratory behavior into the center of an arena containing sucrose drops compared to sitters who hug the edges of the arena and exhibit thigmotaxic behavior. Rovers also discover and ingest more sucrose drops than sitters. Sitters become more exploratory with increasing durations of food deprivation and the number of ingestion events also increases progressively with prolonged fasting for both strains. AFA results are matched by strain differences in sucrose responsiveness, starvation resistance, and lipid levels, suggesting that under the same feeding condition, rovers are more motivated to forage than sitters. These findings demonstrate the AFA's ability to effectively discriminate movement and food ingestion patterns of different strains and feeding treatments.
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Affiliation(s)
- Bryon N Hughson
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada
| | - Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada; Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), 180 Dundas St. West, Suite 1400, Toronto, Ontario M5G 1Z8, Canada
| | - Nicholas L Jackson Chornenki
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada
| | - Keith R Murphy
- Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way 3B3, Jupiter, FL 33458, USA; Center on Aging, The Scripps Research Institute, 130 Scripps Way 3B3, Jupiter, FL 33458, USA
| | - William W Ja
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way 3B3, Jupiter, FL 33458, USA; Center on Aging, The Scripps Research Institute, 130 Scripps Way 3B3, Jupiter, FL 33458, USA
| | - Robert Huber
- JP Scott Center for Neuroscience, Mind & Behavior, Biological Sciences, Bowling Green State University, Bowling Green, OH 43614, USA; Radcliffe Institute for Advanced Study, Harvard University, 10 Garden Street, Cambridge, MA 02138, USA
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada; Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), 180 Dundas St. West, Suite 1400, Toronto, Ontario M5G 1Z8, Canada.
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34
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Anreiter I, Sokolowski MB. Deciphering pleiotropy: How complex genes regulate behavior. Commun Integr Biol 2018; 11:1-4. [PMID: 30083283 PMCID: PMC6067849 DOI: 10.1080/19420889.2018.1447743] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 02/28/2018] [Indexed: 11/10/2022] Open
Abstract
The genetic underpinnings of animal behavior are exceedingly complex. Behavioral phenotypes are commonly regulated by many genes, and the behavioral effects of a gene often dependent on environmental conditions and genetic background. To complicate the study of behavioral genetics further, many genes that regulate behavioral phenotypes are themselves very complex genes, with several gene products and functions. One example of such a complex gene is the foraging gene in D. melanogaster. foraging influences many behaviors in the fruit fly, and the key to its effects likely lies in its complex molecular structure. We've recently found that expression levels of a small subset of transcripts of the foraging gene underlie the behavioral differences seen in adult foraging patterns of the rover and sitter D. melanogaster strains. Here we comment on the larger implications of this and other findings on gene regulation and pleiotropy in behavior.
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Affiliation(s)
- Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Ontario, Canada
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Ontario, Canada
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35
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Abstract
Excess adipose fat accumulation, or obesity, is a growing problem worldwide in terms of both the rate of incidence and the severity of obesity-associated metabolic disease. Adipose tissue evolved in animals as a specialized dynamic lipid storage depot: adipose cells synthesize fat (a process called lipogenesis) when energy is plentiful and mobilize stored fat (a process called lipolysis) when energy is needed. When a disruption of lipid homeostasis favors increased fat synthesis and storage with little turnover owing to genetic predisposition, overnutrition or sedentary living, complications such as diabetes and cardiovascular disease are more likely to arise. The vinegar fly Drosophila melanogaster (Diptera: Drosophilidae) is used as a model to better understand the mechanisms governing fat metabolism and distribution. Flies offer a wealth of paradigms with which to study the regulation and physiological effects of fat accumulation. Obese flies accumulate triacylglycerols in the fat body, an organ similar to mammalian adipose tissue, which specializes in lipid storage and catabolism. Discoveries in Drosophila have ranged from endocrine hormones that control obesity to subcellular mechanisms that regulate lipogenesis and lipolysis, many of which are evolutionarily conserved. Furthermore, obese flies exhibit pathophysiological complications, including hyperglycemia, reduced longevity and cardiovascular function - similar to those observed in obese humans. Here, we review some of the salient features of the fly that enable researchers to study the contributions of feeding, absorption, distribution and the metabolism of lipids to systemic physiology.
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Affiliation(s)
- Laura Palanker Musselman
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, NY 13902, USA
| | - Ronald P Kühnlein
- Department of Biochemistry 1, Institute of Molecular Biosciences, University of Graz, Humboldtstraβe 50/II, A-8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
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36
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Malé PJG, Turner KM, Doha M, Anreiter I, Allen AM, Sokolowski MB, Frederickson ME. An ant-plant mutualism through the lens of cGMP-dependent kinase genes. Proc Biol Sci 2018; 284:rspb.2017.0896. [PMID: 28904134 DOI: 10.1098/rspb.2017.0896] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/04/2017] [Indexed: 12/19/2022] Open
Abstract
In plant-animal mutualisms, how an animal forages often determines how much benefit its plant partner receives. In many animals, foraging behaviour changes in response to foraging gene expression or activation of the cGMP-dependent protein kinase (PKG) that foraging encodes. Here, we show that this highly conserved molecular mechanism affects the outcome of a plant-animal mutualism. We studied the two PKG genes of Allomerus octoarticulatus, an Amazonian ant that defends the ant-plant Cordia nodosa against herbivores. Some ant colonies are better 'bodyguards' than others. Working in the field in Peru, we found that colonies fed with a PKG activator recruited more workers to attack herbivores than control colonies. This resulted in less herbivore damage. PKG gene expression in ant workers correlated with whether an ant colony discovered an herbivore and how much damage herbivores inflicted on leaves in a complex way; natural variation in expression levels of the two genes had significant interaction effects on ant behaviour and herbivory. Our results suggest a molecular basis for ant protection of plants in this mutualism.
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Affiliation(s)
- Pierre-Jean G Malé
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
| | - Kyle M Turner
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
| | - Manjima Doha
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
| | - Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, West Tower, 661 University Avenue, Suite 505, Toronto, Ontario, Canada M5G 1M1
| | - Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, West Tower, 661 University Avenue, Suite 505, Toronto, Ontario, Canada M5G 1M1
| | - Megan E Frederickson
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
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37
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Epigenetic switch turns on genetic behavioral variations. Proc Natl Acad Sci U S A 2017; 114:12365-12367. [PMID: 29114044 DOI: 10.1073/pnas.1717376114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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38
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Epigenetic mechanisms modulate differences in Drosophila foraging behavior. Proc Natl Acad Sci U S A 2017; 114:12518-12523. [PMID: 29078350 DOI: 10.1073/pnas.1710770114] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Little is known about how genetic variation and epigenetic marks interact to shape differences in behavior. The foraging (for) gene regulates behavioral differences between the rover and sitter Drosophila melanogaster strains, but the molecular mechanisms through which it does so have remained elusive. We show that the epigenetic regulator G9a interacts with for to regulate strain-specific adult foraging behavior through allele-specific histone methylation of a for promoter (pr4). Rovers have higher pr4 H3K9me dimethylation, lower pr4 RNA expression, and higher foraging scores than sitters. The rover-sitter differences disappear in the presence of G9a null mutant alleles, showing that G9a is necessary for these differences. Furthermore, rover foraging scores can be phenocopied by transgenically reducing pr4 expression in sitters. This compelling evidence shows that genetic variation can interact with an epigenetic modifier to produce differences in gene expression, establishing a behavioral polymorphism in Drosophila.
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Humberg TH, Sprecher SG. Age- and Wavelength-Dependency of Drosophila Larval Phototaxis and Behavioral Responses to Natural Lighting Conditions. Front Behav Neurosci 2017; 11:66. [PMID: 28473759 PMCID: PMC5397426 DOI: 10.3389/fnbeh.2017.00066] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/03/2017] [Indexed: 12/14/2022] Open
Abstract
Animals use various environmental cues as key determinant for their behavioral decisions. Visual systems are hereby responsible to translate light-dependent stimuli into neuronal encoded information. Even though the larval eyes of the fruit fly Drosophila melanogaster are comparably simple, they comprise two types of photoreceptor neurons (PRs), defined by different Rhodopsin genes expressed. Recent findings support that for light avoidance Rhodopsin5 (Rh5) expressing photoreceptors are crucial, while Rhodopsin6 (Rh6) expressing photoreceptors are dispensable under laboratory conditions. However, it remains debated how animals change light preference during larval live. We show that larval negative phototaxis is age-independent as it persists in larvae from foraging to wandering developmental stages. Moreover, if spectrally different Rhodopsins are employed for the detection of different wavelength of light remains unexplored. We found that negative phototaxis can be elicit by light with wavelengths ranging from ultraviolet (UV) to green. This behavior is uniquely mediated by Rh5 expressing photoreceptors, and therefore suggest that this photoreceptor-type is able to perceive UV up to green light. In contrast to laboratory our field experiments revealed that Drosophila larvae uses both types of photoreceptors under natural lighting conditions. All our results, demonstrate that Drosophila larval eyes mediate avoidance of light stimuli with a wide, ecological relevant range of quantity (intensities) and quality (wavelengths). Thus, the two photoreceptor-types appear more likely to play a role in different aspects of phototaxis under natural lighting conditions, rather than color discrimination.
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Affiliation(s)
| | - Simon G Sprecher
- Department of Biology, University of FribourgFribourg, Switzerland
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40
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Wang S, Sokolowski MB. Aggressive behaviours, food deprivation and the foraging gene. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170042. [PMID: 28484630 PMCID: PMC5414267 DOI: 10.1098/rsos.170042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/22/2017] [Indexed: 06/07/2023]
Abstract
A pleiotropic gene governs multiple traits, which might constrain the evolution of complexity due to conflicting selection on these traits. However, if the pleiotropic effect is modular, then this can facilitate synergistic responses to selection on functionally related traits, thereby leveraging the evolution of complexity. To understand the evolutionary consequence of pleiotropy, the relation among functionally different traits governed by the same gene is key. We examined a pleiotropic function of the foraging (for) gene with its rover and sitter allelic variants in fruit fly, Drosophila melanogaster. We measured for's effect on adult male aggressive behaviours and whether this effect was shaped by for's known role in food-related traits. Rover exhibited higher levels of offensive behaviour than sitters and s2, a sitter-like mutant on rover genetic background. With a Markov chain model, we estimated the rate of aggression escalation, and found that the rover pattern of aggressive escalation more rapidly intensified fights. Subsequent analysis revealed that this was not caused by for's effect on food-related traits, suggesting that for might directly regulate aggressive behaviours. Food deprivation did not elevate aggression, but reduced intermediate-level aggressive behaviours. Aggression and other foraging-related behaviour might comprise a synergistic trait module underlaid by this pleiotropic gene.
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Affiliation(s)
- Silu Wang
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, CanadaV6T 1Z4
| | - Marla B. Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, CanadaM5S 3B2
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), 180 Dundas Street West, Suite 1400, Toronto, Ontario, CanadaM5G 1Z8
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