1
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Ueno T, Takahashi Y. Mitochondrial polymorphism shapes intrapopulation behavioural variation in wild Drosophila. Biol Lett 2021; 17:20210194. [PMID: 34314641 PMCID: PMC8315832 DOI: 10.1098/rsbl.2021.0194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/05/2021] [Indexed: 11/12/2022] Open
Abstract
Intrapopulation variation in behaviour, including activity, boldness and aggressiveness, is becoming more widely recognized and is hypothesized to substantially affect ecological and evolutionary dynamics. Although previous studies used candidate-gene approaches and genome-wide association analyses to identify genes correlated with variations in activity and aggressiveness, behavioural variation may not be fully captured in the nuclear genome, as it does not account for mitochondrial genomes. Mitochondrial genes encode products that are key regulators of the cellular energy-producing pathways in metabolic processes and are thought to play a significant role in life-history and reproductive traits. In this study, we considered many isofemale lines of Drosophila immigrans established from two wild populations to investigate whether intrapopulation variation in the mitochondrial genome affected activity level within this species. We identified two major haplogroups in these populations, and activity levels in both larvae and adults differed significantly between the two haplogroups. This result indicated that intrapopulation variation in activity level may be partially controlled by mitochondrial genes, along with the interaction between nuclear and mitochondrial genes and the age of individual organisms.
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Affiliation(s)
- Takahisa Ueno
- Graduate School of Science and Engineering, Chiba University, Chiba, Japan
| | - Yuma Takahashi
- Graduate School of Science, Chiba University, Chiba, Japan
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2
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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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3
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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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4
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J Gray L, B Sokolowski M, J Simpson S. Drosophila as a useful model for understanding the evolutionary physiology of obesity resistance and metabolic thrift. Fly (Austin) 2021; 15:47-59. [PMID: 33704003 DOI: 10.1080/19336934.2021.1896960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Evolved metabolic thriftiness in humans is a proposed contributor to the obesity epidemic. Insect models have been shown to evolve both 'metabolic thrift' in response to rearing on high-protein diets that promote leanness, and 'obesity resistance' when reared on fattening high-carbohydrate, low-protein foods. Despite the hypothesis that human obesity is caused by evolved metabolic thrift, genetic contributions to this physiological trait remain elusive. Here we conducted a pilot study to determine whether thrift and obesity resistance can arise under laboratory based 'quasi-natural selection' in the genetic model organism Drosophila melanogaster. We found that both these traits can evolve within 16 generations. Contrary to predictions from the 'thrifty genotype/phenotype' hypothesis, we found that when animals from a metabolic thrift inducing high-protein environment are mismatched to fattening high-carbohydrate foods, they did not become 'obese'. Rather, they accumulate less triglyceride than control animals, not more. We speculate that this may arise through as yet un-quantified parental effects - potentially epigenetic. This study establishes that D. melanogaster could be a useful model for elucidating the role of the trans- and inter-generational effects of diet on the genetics of metabolic traits in higher animals.
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Affiliation(s)
- Lindsey J Gray
- Charles Perkins Centre and School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Marla B Sokolowski
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON Canada
| | - Stephen J Simpson
- Charles Perkins Centre and School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
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5
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Ueno T, Takahashi Y. Intrapopulation genetic variation in the level and rhythm of daily activity in Drosophila immigrans. Ecol Evol 2020; 10:14388-14393. [PMID: 33391722 PMCID: PMC7771174 DOI: 10.1002/ece3.7041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/07/2020] [Accepted: 10/30/2020] [Indexed: 01/12/2023] Open
Abstract
Genetic diversity within a population, such as polymorphisms and personality, is considered to improve population performance because such intraspecific variations have the potential to alleviate the competition for a limited resource or the risk of predation and sexual harassment at a population level. Variation in the level and rhythm of daily activity in a population could also affect population performance by directly altering ecological, social, and sexual interactions among individuals. However, it remains to be elucidated whether such intra-population variation in the level and rhythms of daily activity exists in a natural population. Here, we investigated the genetic variation in daily activity within a single natural population of Drosophila immigrans. We established 21 isofemale lines from a single natural population and measured larval activity level and the level and daily pattern of adult activity over a 24 hr period. Larval activity level significantly varied among isofemale lines. Likewise, the activity level in the adult stage significantly varied among lines. The significant variation was also found in the daily pattern of adult activity; some lines showed greater activity level in the daytime, and others showed greater activity level in the night. Our results consistently suggest that there is a genetic variation in behavioral activity in a natural population, probably contributing to shaping the population performance.
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Affiliation(s)
- Takahisa Ueno
- Graduate School of Science and EngineeringChiba UniversityChibaJapan
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6
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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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7
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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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8
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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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9
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Neitzel LR, Broadus MR, Zhang N, Sawyer L, Wallace HA, Merkle JA, Jodoin JN, Sitaram P, Crispi EE, Rork W, Lee LA, Pan D, Gould KL, Page-McCaw A, Lee E. Characterization of a cdc14 null allele in Drosophila melanogaster. Biol Open 2018; 7:bio.035394. [PMID: 29945873 PMCID: PMC6078348 DOI: 10.1242/bio.035394] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cdc14 is an evolutionarily conserved serine/threonine phosphatase. Originally identified in Saccharomyces cerevisiae as a cell cycle regulator, its role in other eukaryotic organisms remains unclear. In Drosophila melanogaster, Cdc14 is encoded by a single gene, thus facilitating its study. We found that Cdc14 expression is highest in the testis of adult flies and that cdc14 null flies are viable. cdc14 null female and male flies do not display altered fertility. cdc14 null males, however, exhibit decreased sperm competitiveness. Previous studies have shown that Cdc14 plays a role in ciliogenesis during zebrafish development. In Drosophila, sensory neurons are ciliated. We found that the Drosophila cdc14 null mutants have defects in chemosensation and mechanosensation as indicated by decreased avoidance of repellant substances and decreased response to touch. In addition, we show that cdc14 null mutants have defects in lipid metabolism and resistance to starvation. These studies highlight the diversity of Cdc14 function in eukaryotes despite its structural conservation. Summary: The Cdc14 phosphatase has been implicated in cell cycle regulation in S. cerevisiae. We show that Drosophila cdc14 mutants are viable, but exhibit defects in sperm competition, chemosensation, and mechanosensation.
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Affiliation(s)
- Leif R Neitzel
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Matthew R Broadus
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Nailing Zhang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Leah Sawyer
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Heather A Wallace
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Division of Genetics, Brigham and Women's Hospital, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Julie A Merkle
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jeanne N Jodoin
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Poojitha Sitaram
- Department of Microbiology, New York University Langone Medical Center, New York, NY 10016, USA
| | - Emily E Crispi
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - William Rork
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Laura A Lee
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Duojia Pan
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Andrea Page-McCaw
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA .,Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA .,Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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10
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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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11
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Feeding-Related Traits Are Affected by Dosage of the foraging Gene in Drosophila melanogaster. Genetics 2016; 205:761-773. [PMID: 28007892 DOI: 10.1534/genetics.116.197939] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/03/2016] [Indexed: 12/31/2022] Open
Abstract
Nutrient acquisition and energy storage are critical parts of achieving metabolic homeostasis. The foraging gene in Drosophila melanogaster has previously been implicated in multiple feeding-related and metabolic traits. Before foraging's functions can be further dissected, we need a precise genetic null mutant to definitively map its amorphic phenotypes. We used homologous recombination to precisely delete foraging, generating the for0 null allele, and used recombineering to reintegrate a full copy of the gene, generating the {forBAC} rescue allele. We show that a total loss of foraging expression in larvae results in reduced larval path length and food intake behavior, while conversely showing an increase in triglyceride levels. Furthermore, varying foraging gene dosage demonstrates a linear dose-response on these phenotypes in relation to foraging gene expression levels. These experiments have unequivocally proven a causal, dose-dependent relationship between the foraging gene and its pleiotropic influence on these feeding-related traits. Our analysis of foraging's transcription start sites, termination sites, and splicing patterns using rapid amplification of cDNA ends (RACE) and full-length cDNA sequencing, revealed four independent promoters, pr1-4, that produce 21 transcripts with nine distinct open reading frames (ORFs). The use of alternative promoters and alternative splicing at the foraging locus creates diversity and flexibility in the regulation of gene expression, and ultimately function. Future studies will exploit these genetic tools to precisely dissect the isoform- and tissue-specific requirements of foraging's functions and shed light on the genetic control of feeding-related traits involved in energy homeostasis.
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