1
|
Stuart SH, Ahmed ACC, Kilikevicius L, Robinson GE. Effects of microRNA-305 knockdown on brain gene expression associated with division of labor in honey bee colonies (Apis mellifera). J Exp Biol 2024; 227:jeb246785. [PMID: 38517067 PMCID: PMC11112348 DOI: 10.1242/jeb.246785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 03/13/2024] [Indexed: 03/23/2024]
Abstract
Division of labor in honey bee colonies is based on the behavioral maturation of adult workers that involves a transition from working in the hive to foraging. This behavioral maturation is associated with distinct task-related transcriptomic profiles in the brain and abdominal fat body that are related to multiple regulatory factors including juvenile hormone (JH) and queen mandibular pheromone (QMP). A prominent physiological feature associated with behavioral maturation is a loss of abdominal lipid mass as bees transition to foraging. We used transcriptomic and physiological analyses to study whether microRNAs (miRNAs) are involved in the regulation of division of labor. We first identified two miRNAs that showed patterns of expression associated with behavioral maturation, ame-miR-305-5p and ame-miR-375-3p. We then downregulated the expression of these two miRNAs with sequence-specific antagomirs. Neither ame-miR-305-5p nor ame-miR-375-3p knockdown in the abdomen affected abdominal lipid mass on their own. Similarly, knockdown of ame-miR-305-5p in combination with JH or QMP also did not affect lipid mass. By contrast, ame-miR-305-5p knockdown in the abdomen caused substantial changes in gene expression in the brain. Brain gene expression changes included genes encoding transcription factors previously implicated in behavioral maturation. The results of these functional genomic experiments extend previous correlative associations of microRNAs with honey bee division of labor and point to specific roles for ame-miR-305-5p.
Collapse
Affiliation(s)
- Sarai H. Stuart
- Program in Ecology, Evolution, and Conservation Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Amy C. Cash Ahmed
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Laura Kilikevicius
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Gene E. Robinson
- Program in Ecology, Evolution, and Conservation Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Department of Entomology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
2
|
Fine JD, Cox-Foster DL, Moor KJ, Chen R, Avalos A. Trisiloxane Surfactants Negatively Affect Reproductive Behaviors and Enhance Viral Replication in Honey Bees. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024; 43:222-233. [PMID: 37861380 DOI: 10.1002/etc.5771] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/06/2023] [Accepted: 10/18/2023] [Indexed: 10/21/2023]
Abstract
Trisiloxane surfactants are often applied in formulated adjuvant products to blooming crops, including almonds, exposing the managed honey bees (Apis mellifera) used for pollination of these crops and persisting in colony matrices, such as bee bread. Despite this, little is known regarding the effects of trisiloxane surfactants on important aspects of colony health, such as reproduction. In the present study, we use laboratory assays to examine how exposure to field-relevant concentrations of three trisiloxane surfactants found in commonly used adjuvant formulations affect queen oviposition rates, worker interactions with the queen, and worker susceptibility to endogenous viral pathogens. Trisiloxane surfactants were administered at 5 mg/kg in pollen supplement diet for 14 days. No effects on worker behavior or physiology could be detected, but our results demonstrate that hydroxy-capped trisiloxane surfactants can negatively affect queen oviposition and methyl-capped trisiloxane surfactants cause increased replication of Deformed Wing Virus in workers, suggesting that trisiloxane surfactant use while honey bees are foraging may negatively impact colony longevity and growth. Environ Toxicol Chem 2024;43:222-233. © 2023 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
Collapse
Affiliation(s)
- Julia D Fine
- US Department of Agriculture-Agricultural Research Service Invasive Species and Pollinator Health Research Unit, Davis, California, USA
| | - Diana L Cox-Foster
- US Department of Agriculture-Agricultural Research Service Pollinating Insect Research Unit, Logan, Utah, USA
| | - Kyle J Moor
- Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, Logan, Utah, USA
| | - Ruiwen Chen
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Arian Avalos
- US Department of Agriculture-Agricultural Research Service Honey Bee Breeding, Genetics, and Physiology Research Laboratory, Baton Rouge, Louisiana, USA
| |
Collapse
|
3
|
Bresnahan ST, Galbraith D, Ma R, Anton K, Rangel J, Grozinger CM. Beyond conflict: Kinship theory of intragenomic conflict predicts individual variation in altruistic behaviour. Mol Ecol 2023; 32:5823-5837. [PMID: 37746895 DOI: 10.1111/mec.17145] [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: 06/19/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/26/2023]
Abstract
Behavioural variation is essential for animals to adapt to different social and environmental conditions. The Kinship Theory of Intragenomic Conflict (KTIC) predicts that parent-specific alleles can support different behavioural strategies to maximize allele fitness. Previous studies, including in honey bees (Apis mellifera), supported predictions of the KTIC for parent-specific alleles to promote selfish behaviour. Here, we test the KTIC prediction that for altruism-promoting genes (i.e. those that promote behaviours that support the reproductive fitness of kin), the allele with the higher altruism optimum should be selected to be expressed while the other is silenced. In honey bee colonies, workers act altruistically when tending to the queen by performing a 'retinue' behaviour, distributing the queen's mandibular pheromone (QMP) throughout the hive. Workers exposed to QMP do not activate their ovaries, ensuring they care for the queen's brood instead of competing to lay unfertilized eggs. Due to the haplodiploid genetics of honey bees, the KTIC predicts that response to QMP is favoured by the maternal genome. We report evidence for parent-of-origin effects on the retinue response behaviour, ovarian development and gene expression in brains of worker honey bees exposed to QMP, consistent with the KTIC. Additionally, we show enrichment for genes with parent-of-origin expression bias within gene regulatory networks associated with variation in bees' response to QMP. Our study demonstrates that intragenomic conflict can shape diverse social behaviours and influence expression patterns of single genes as well as gene networks.
Collapse
Affiliation(s)
- Sean T Bresnahan
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
- Intercollege Graduate Degree Program in Molecular, Cellular, and Integrative Biosciences, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - David Galbraith
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Rong Ma
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Kate Anton
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Juliana Rangel
- Department of Entomology, Texas A&M University, College Station, Texas, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| |
Collapse
|
4
|
Caminer MA, Libbrecht R, Majoe M, Ho DV, Baumann P, Foitzik S. Task-specific odorant receptor expression in worker antennae indicates that sensory filters regulate division of labor in ants. Commun Biol 2023; 6:1004. [PMID: 37783732 PMCID: PMC10545721 DOI: 10.1038/s42003-023-05273-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 08/22/2023] [Indexed: 10/04/2023] Open
Abstract
Division of labor (DOL) is a characteristic trait of insect societies, where tasks are generally performed by specialized individuals. Inside workers focus on brood or nest care, while others take risks by foraging outside. Theory proposes that workers have different thresholds to perform certain tasks when confronted with task-related stimuli, leading to specialization and consequently DOL. Workers are presumed to vary in their response to task-related cues rather than in how they perceive such information. Here, we test the hypothesis that DOL instead stems from workers varying in their efficiency to detect stimuli of specific tasks. We use transcriptomics to measure mRNA expression levels in the antennae and brain of nurses and foragers of the ant Temnothorax longispinosus. We find seven times as many genes to be differentially expressed between behavioral phenotypes in the antennae compared to the brain. Moreover, half of all odorant receptors are differentially expressed, with an overrepresentation of the 9-exon gene family upregulated in the antennae of nurses. Nurses and foragers thus apparently differ in the perception of their olfactory environment and task-related signals. Our study supports the hypothesis that antennal sensory filters predispose workers to specialize in specific tasks.
Collapse
Affiliation(s)
- Marcel A Caminer
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Romain Libbrecht
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS, University of Tours, Tours, France
| | - Megha Majoe
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - David V Ho
- Institute of Developmental and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Peter Baumann
- Institute of Developmental and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
- Institute of Molecular Biology, Mainz, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| |
Collapse
|
5
|
Fine JD, Foster LJ, McAfee A. Indirect exposure to insect growth disruptors affects honey bee (Apis mellifera) reproductive behaviors and ovarian protein expression. PLoS One 2023; 18:e0292176. [PMID: 37782633 PMCID: PMC10545116 DOI: 10.1371/journal.pone.0292176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/14/2023] [Indexed: 10/04/2023] Open
Abstract
Pesticide exposure and queen loss are considered to be major causes of honey bee colony mortality, yet little is known regarding the effects of regularly encountered agrochemicals on honey bee reproduction. Here, we present the results of a two-generational study using specialized cages to expose queens to commonly used insect growth disrupting pesticides (IGDs) via their retinue of worker bees. Under IGD exposure, we tracked queen performance and worker responses to queens, then the performance of the exposed queens' offspring was assessed to identify patterns that may contribute to the long-term health and stability of a social insect colony. The positive control, novaluron, resulted in deformed larvae hatching from eggs laid by exposed queens, and methoxyfenozide, diflubenzuron, and novaluron caused a slight decrease in daily egg laying rates, but this was not reflected in the total egg production over the course of the experiment. Curiously, eggs laid by queens exposed to pyriproxyfen exhibited increased hatching rates, and those larvae developed into worker progeny with increased responsiveness to their queens. Additionally, pyriproxyfen and novaluron exposure affected the queen ovarian protein expression, with the overwhelming majority of differentially expressed proteins coming from the pyriproxyfen exposure. We discuss these results and the potential implications for honey bee reproduction and colony health.
Collapse
Affiliation(s)
- Julia D. Fine
- Invasive Species and Pollinator Health Research Unit, USDA-ARS, Davis, CA, United States of America
| | - Leonard J. Foster
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Alison McAfee
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States of America
| |
Collapse
|
6
|
Martins JR, Pinheiro DG, Ahmed ACC, Giuliatti S, Mizzen CA, Bitondi MMG. Genome-wide analysis of the chromatin sites targeted by HEX 70a storage protein in the honeybee brain and fat body. INSECT MOLECULAR BIOLOGY 2023; 32:277-304. [PMID: 36630080 DOI: 10.1111/imb.12830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 12/12/2022] [Indexed: 05/15/2023]
Abstract
Hexamerins, the proteins massively stored in the larval haemolymph of insects, are gradually used throughout metamorphosis as a source of raw material and energy for the development of adult tissues. Such behaviour defined hexamerins as storage proteins. Immunofluorescence experiments coupled with confocal microscopy show a hexamerin, HEX 70a, in the nucleus of the brain and fat body cells from honeybee workers, an unexpected localization for a storage protein. HEX 70a colocalizes with fibrillarin, a nucleolar-specific protein and H3 histone, thus suggesting a potential role as a chromatin-binding protein. This was investigated through chromatin immunoprecipitation and high-throughput DNA sequencing (ChIP-seq). The significant HEX 70a-DNA binding sites were mainly localized at the intergenic, promoter and intronic regions. HEX 70a targeted DNA stretches mapped to the genomic regions encompassing genes with relevant functional attributes. Several HEX 70a targeted genes were associated with H3K27ac or/and H3K27me3, known as active and repressive histone marks. Brain and fat body tissues shared a fraction of the HEX 70 targeted genes, and tissue-specific targets were also detected. The presence of overrepresented DNA motifs in the binding sites is consistent with specific HEX 70a-chromatin association. In addition, a search for HEX 70a targets in RNA-seq public libraries of fat bodies from nurses and foragers revealed differentially expressed targets displaying hex 70a-correlated developmental expression, thus supporting a regulatory activity for HEX 70a. Our results support the premise that HEX 70a is a moonlighting protein that binds chromatin and has roles in the brain and fat body cell nuclei, apart from its canonical role as a storage protein.
Collapse
Affiliation(s)
- Juliana R Martins
- Faculdade de Medicina de Ribeirão Preto, Departamento de Genética, Ribeirão Preto, Brazil
| | - Daniel G Pinheiro
- Departamento de Biotecnologia Agropecuária e Ambiental, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP), Jaboticabal, Brazil
| | - Amy C C Ahmed
- University of Illinois at Urbana-Champaign, Carl R. Woese Institute for Genomic Biology, Urbana, Illinois, USA
| | - Silvana Giuliatti
- Faculdade de Medicina de Ribeirão Preto, Departamento de Genética, Ribeirão Preto, Brazil
| | - Craig A Mizzen
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Márcia M G Bitondi
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Ribeirão Preto, Brazil
| |
Collapse
|
7
|
He Q, Zhang Y. Kr-h1, a Cornerstone Gene in Insect Life History. Front Physiol 2022; 13:905441. [PMID: 35574485 PMCID: PMC9092015 DOI: 10.3389/fphys.2022.905441] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 04/13/2022] [Indexed: 11/13/2022] Open
Abstract
Insect life cycle is coordinated by hormones and their downstream effectors. Krüppel homolog1 (Kr-h1) is one of the crucial effectors which mediates the actions of the two critical hormones of insects, the juvenile hormone (JH) and 20-hydroxyecdysone (20E). It is a transcription factor with a DNA-binding motif of eight C2H2 zinc fingers which is found to be conserved among insect orders. The expression of Kr-h1 is fluctuant during insect development with high abundance in juvenile instars and lower levels in the final instar and pupal stage, and reappearance in adults, which is governed by the coordination of JH, 20E, and miRNAs. The dynamic expression pattern of Kr-h1 is closely linked to its function in the entire life of insects. Over the past several years, accumulating studies have advanced our understanding of the role of Kr-h1 during insect development. It acts as a universal antimetamorphic factor in both hemimetabolous and holometabolous species by directly inhibiting the transcription of 20E signaling genes Broad-Complex (Br-C) and Ecdysone induced protein 93F (E93), and steroidogenic enzyme genes involved in ecdysone biosynthesis. Meanwhile, it promotes vitellogenesis and ovarian development in the majority of studied insects. In addition, Kr-h1 regulates insect behavioral plasticity and caste identity, neuronal morphogenesis, maturation of sexual behavior, as well as embryogenesis and metabolic homeostasis. Hence, Kr-h1 acts as a cornerstone regulator in insect life.
Collapse
Affiliation(s)
- Qianyu He
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Yuanxi Zhang
- Daqing Municipal Ecology and Environment Bureau, Daqing, China
| |
Collapse
|
8
|
Sun YY, Fu DY, Liu B, Wang LJ, Chen H. Roles of Krüppel Homolog 1 and Broad-Complex in the Development of Dendroctonus armandi (Coleoptera: Scolytinae). Front Physiol 2022; 13:865442. [PMID: 35464080 PMCID: PMC9019567 DOI: 10.3389/fphys.2022.865442] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/23/2022] [Indexed: 11/13/2022] Open
Abstract
In insects, metamorphosis is controlled by juvenile hormone (JH) and 20-hydroxyecdysone (20E). Krüppel homolog 1 (Kr-h1), a key JH-early inducible gene, is responsible for the suppression of metamorphosis and the regulation of the Broad-Complex (Br-C) gene, which is induced by 20E and functions as a “pupal specifier”. In this study, we identified and characterized the expression patterns and tissue distribution of DaKr-h1 and DaBr-C at various developmental stages of Dendroctonus armandi. The expression of the two genes was induced by JH analog (JHA) methoprene and 20E, and their functions were investigated by RNA interference. DaKr-h1 and DaBr-C were predominantly expressed in the heads of larvae and were significantly downregulated during the molting stage. In contrast, the DaKr-h1 transcript level was highest in the adult anterior midgut. DaBr-C was mainly expressed in female adults, with the highest transcript levels in the ovaries. In the larval and pupal stages, both JHA and 20E significantly induced DaKr-h1, but only 20E significantly induced DaBr-C, indicating the importance of hormones in metamorphosis. DaKr-h1 knockdown in larvae upregulated DaBr-C expression, resulting in precocious metamorphosis from larvae to pupae and the formation of miniature pupae. DaKr-h1 knockdown in pupae suppressed DaBr-C expression, increased emergence, caused abnormal morphology, and caused the formation of small-winged adults. These results suggest that DaKr-h1 is required for the metamorphosis of D. armandi. Our findings provide insight into the roles of DaKr-h1 and DaBr-C in JH-induced transcriptional repression and highlight DaKr-h1 as a potential target for metamorphosis suppression in D. armandi.
Collapse
Affiliation(s)
- Ya-Ya Sun
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- College of Forestry, Northwest A&F University, Xianyang, China
| | - Dan-Yang Fu
- College of Forestry, Northwest A&F University, Xianyang, China
| | - Bin Liu
- College of Forestry, Northwest A&F University, Xianyang, China
| | - Lin-Jun Wang
- College of Forestry, Northwest A&F University, Xianyang, China
| | - Hui Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- *Correspondence: Hui Chen,
| |
Collapse
|
9
|
Tsvetkov N, Zayed A. Searching beyond the streetlight: Neonicotinoid exposure alters the neurogenomic state of worker honey bees. Ecol Evol 2021; 11:18733-18742. [PMID: 35003705 PMCID: PMC8717355 DOI: 10.1002/ece3.8480] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 12/01/2021] [Accepted: 12/06/2021] [Indexed: 12/13/2022] Open
Abstract
Neonicotinoid insecticides have been implicated in honey bee declines, with many studies showing that sublethal exposure impacts bee behaviors such as foraging, learning, and memory. Despite the large number of ecotoxicological studies carried out to date, most focus on a handful of worker phenotypes leading to a "streetlight effect" where the a priori choice of phenotypes to measure may influence the results and conclusions arising from the studies. This bias can be overcome with the use of toxicological transcriptomics, where changes in gene expression can provide a more objective view of how pesticides alter animal traits. Here, we used RNA sequencing to examine the changes in neurogenomic states of nurse and forager honey bees that were naturally exposed to neonicotinoids in the field and artificially exposed to neonicotinoids in a controlled experiment. We found that neonicotinoid exposure influenced the neurogenomic state of foragers and nurses in different ways; foragers experienced shifts in expression of genes involved in cognition and development, while nurses experienced shifts in expression of genes involved in metabolism. Our study suggests that neonicotinoids influence nurse and forager bees in a different manner. We also found no to minimal overlap in the differentially expressed genes in our study and in previously published studies, which might help reconcile the seemingly contradictory results often reported in the neonicotinoid literature.
Collapse
Affiliation(s)
| | - Amro Zayed
- Department of BiologyYork UniversityTorontoONCanada
| |
Collapse
|
10
|
Gospocic J, Glastad KM, Sheng L, Shields EJ, Berger SL, Bonasio R. Kr-h1 maintains distinct caste-specific neurotranscriptomes in response to socially regulated hormones. Cell 2021; 184:5807-5823.e14. [PMID: 34739833 DOI: 10.1016/j.cell.2021.10.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 07/13/2021] [Accepted: 10/07/2021] [Indexed: 10/19/2022]
Abstract
Behavioral plasticity is key to animal survival. Harpegnathos saltator ants can switch between worker and queen-like status (gamergate) depending on the outcome of social conflicts, providing an opportunity to study how distinct behavioral states are achieved in adult brains. Using social and molecular manipulations in live ants and ant neuronal cultures, we show that ecdysone and juvenile hormone drive molecular and functional differences in the brains of workers and gamergates and direct the transcriptional repressor Kr-h1 to different target genes. Depletion of Kr-h1 in the brain caused de-repression of "socially inappropriate" genes: gamergate genes were upregulated in workers, whereas worker genes were upregulated in gamergates. At the phenotypic level, loss of Kr-h1 resulted in the emergence of worker-specific behaviors in gamergates and gamergate-specific traits in workers. We conclude that Kr-h1 is a transcription factor that maintains distinct brain states established in response to socially regulated hormones.
Collapse
Affiliation(s)
- Janko Gospocic
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Urology and Institute of Neuropathology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Karl M Glastad
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Lihong Sheng
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Emily J Shields
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Urology and Institute of Neuropathology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Shelley L Berger
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania School of Arts and Sciences, Philadelphia, PA 19104, USA.
| | - Roberto Bonasio
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| |
Collapse
|
11
|
Litsey EM, Chung S, Fine JD. The Behavioral Toxicity of Insect Growth Disruptors on Apis mellifera Queen Care. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.729208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
As social insects, honey bees (Apis mellifera) rely on the coordinated performance of various behaviors to ensure that the needs of the colony are met. One of the most critical of these behaviors is the feeding and care of egg laying honey bee queens by non-fecund female worker attendants. These behaviors are crucial to honey bee reproduction and are known to be elicited by the queen’s pheromone blend. The degree to which workers respond to this blend can vary depending on their physiological status, but little is known regarding the impacts of developmental exposure to agrochemicals on this behavior. This work investigated how exposing workers during larval development to chronic sublethal doses of insect growth disruptors affected their development time, weight, longevity, and queen pheromone responsiveness as adult worker honey bees. Exposure to the juvenile hormone analog pyriproxyfen consistently shortened the duration of pupation, and pyriproxyfen and diflubenzuron inconsistently reduced the survivorship of adult bees. Finally, pyriproxyfen and methoxyfenozide treated bees were found to be less responsive to queen pheromone relative to other treatment groups. Here, we describe these results and discuss their possible physiological underpinnings as well as their potential impacts on honey bee reproduction and colony performance.
Collapse
|
12
|
Crone MK, Grozinger CM. Pollen protein and lipid content influence resilience to insecticides in honey bees ( Apis mellifera). J Exp Biol 2021; 224:jeb.242040. [PMID: 33758024 DOI: 10.1242/jeb.242040] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/17/2021] [Indexed: 12/19/2022]
Abstract
In honey bees (Apis mellifera), there is growing evidence that the impacts of multiple stressors can be mitigated by quality nutrition. Pollen, which is the primary source of protein and lipids in bees diets, is particularly critical for generating more resilient phenotypes. Here, we evaluate the relationship between pollen protein-to-lipid ratios (P:Ls) and honey bee insecticide resilience. We hypothesized that pollen diets richer in lipids would lead to increased survival in bees exposed to insecticides, as pollen-derived lipids have previously been shown to improve bee resilience to pathogens and parasites. Furthermore, lipid metabolic processes are altered in bees exposed to insecticides.We fed age-matched bees pollen diets of different P:Ls by altering a base pollen by either adding protein (casein powder) or lipids (canola oil) and simulating chronic insecticide exposure by feeding bees an organophosphate (Chlorpyrifos). We also tested pollen diets of naturally different P:Ls to determine if results are consistent. Linear regression analysis revealed that mean survival time for altered diets was best explained by protein concentration (p =0.04 , adjusted R2 =0.92), and that mean survival time for natural diets was best explained by P:L ratio (p =0.008 , adjusted R2 =0.93). Our results indicate that higher ratios of dietary protein to lipid has a negative effect on bee physiology when combined with insecticide exposure, while lower ratios have a positive effect. These results suggest that protein and lipid intake differentially influence insecticide response in bees, laying the groundwork for future studies of metabolic processes and development of improved diets.
Collapse
Affiliation(s)
- Makaylee K Crone
- Intercollege Graduate Program in Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, USA
| |
Collapse
|
13
|
Tsang SSK, Law STS, Li C, Qu Z, Bendena WG, Tobe SS, Hui JHL. Diversity of Insect Sesquiterpenoid Regulation. Front Genet 2020; 11:1027. [PMID: 33133135 PMCID: PMC7511761 DOI: 10.3389/fgene.2020.01027] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/11/2020] [Indexed: 12/11/2022] Open
Abstract
Insects are arguably the most successful group of animals in the world in terms of both species numbers and diverse habitats. The sesquiterpenoids juvenile hormone, methyl farnesoate, and farnesoic acid are well known to regulate metamorphosis, reproduction, sexual dimorphism, eusociality, and defense in insects. Nevertheless, different insects have evolved with different sesquiterpenoid biosynthetic pathway as well as products. On the other hand, non-coding RNAs such as microRNAs have been implicated in regulation of many important biological processes, and have recently been explored in the regulation of sesquiterpenoid production. In this review, we summarize the latest findings on the diversity of sesquiterpenoids reported in different groups of insects, as well as the recent advancements in the understanding of regulation of sesquiterpenoid production by microRNAs.
Collapse
Affiliation(s)
- Stacey S K Tsang
- Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Sean T S Law
- Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Chade Li
- Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Zhe Qu
- Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | | | - Stephen S Tobe
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Jerome H L Hui
- Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| |
Collapse
|
14
|
Nagel M, Qiu B, Brandenborg LE, Larsen RS, Ning D, Boomsma JJ, Zhang G. The gene expression network regulating queen brain remodeling after insemination and its parallel use in ants with reproductive workers. SCIENCE ADVANCES 2020; 6:6/38/eaaz5772. [PMID: 32938672 PMCID: PMC7494347 DOI: 10.1126/sciadv.aaz5772] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 07/27/2020] [Indexed: 05/16/2023]
Abstract
Caste differentiation happens early in development to produce gynes as future colony germlines and workers as present colony soma. However, gynes need insemination to become functional queens, a transition that initiates reproductive role differentiation relative to unmated gynes. Here, we analyze the anatomy and transcriptomes of brains during this differentiation process within the reproductive caste of Monomorium pharaonis Insemination terminated brain growth, whereas unmated control gynes continued to increase brain volume. Transcriptomes revealed a specific gene regulatory network (GRN) mediating both brain anatomy changes and behavioral modifications. This reproductive role differentiation GRN hardly overlapped with the gyne-worker caste differentiation GRN, but appears to be also used by distantly related ants where workers became germline individuals after the queen caste was entirely or partially lost. The genes corazonin and neuroparsin A in the anterior neurosecretory cells were overexpressed in individuals with reduced or nonreproductive roles across all four ant species investigated.
Collapse
Affiliation(s)
- Manuel Nagel
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Bitao Qiu
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Centre for Social Evolution, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Lisa Eigil Brandenborg
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Rasmus Stenbak Larsen
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Dongdong Ning
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Jacobus Jan Boomsma
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Centre for Social Evolution, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Guojie Zhang
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark.
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
- China National GeneBank, BGI-Shenzhen, Jinsha Road, Shenzhen 518083, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223, China
| |
Collapse
|
15
|
Orlova M, Starkey J, Amsalem E. A small family business: synergistic and additive effects of the queen and the brood on worker reproduction in a primitively eusocial bee. J Exp Biol 2020; 223:jeb217547. [PMID: 31953359 DOI: 10.1242/jeb.217547] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/08/2020] [Indexed: 01/04/2023]
Abstract
The mechanisms that maintain reproductive division of labor in social insects are still incompletely understood. Most studies focus on the relationship between adults, overlooking another important stakeholder - the juveniles. Recent studies show that not only the queen but also the brood regulate worker reproduction. However, how the two coordinate to maintain reproductive monopoly remained unexplored. Here, we disentangled the roles of the brood and the queen in primitively eusocial bees (Bombus impatiens) by examining their separated and combined effects on worker behavioral, physiological and brain gene expression. We found that young larvae produce a releaser effect on workers, decreasing oviposition and aggression, while the queen produces both releaser and primer effects, modifying worker behavior and reproductive physiology. The expression of reproduction- and aggression-related genes was altered in the presence of both queen and brood but was stronger or the same in the presence of the queen. We identified two types of interactions between the queen and the brood in regulating worker reproduction: (1) synergistic interactions regulating worker physiology, where the combined effect of the queen and the brood on worker physiology was greater than their separate effects; (2) additive interactions, where the combined effect of the queen and the brood on worker behavior was similar to the sum of their separate effects. Our results suggest that the queen and the brood interact synergistically and additively to regulate worker behavior and reproduction, and this interaction exists at multiple regulatory levels.
Collapse
Affiliation(s)
- Margarita Orlova
- Department of Entomology, Center for Chemical Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Jesse Starkey
- Department of Entomology, Center for Chemical Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Etya Amsalem
- Department of Entomology, Center for Chemical Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
16
|
Chandra V, Fetter-Pruneda I, Oxley PR, Ritger AL, McKenzie SK, Libbrecht R, Kronauer DJC. Social regulation of insulin signaling and the evolution of eusociality in ants. Science 2018; 361:398-402. [PMID: 30049879 PMCID: PMC6178808 DOI: 10.1126/science.aar5723] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 04/01/2018] [Accepted: 05/30/2018] [Indexed: 12/15/2022]
Abstract
Queens and workers of eusocial Hymenoptera are considered homologous to the reproductive and brood care phases of an ancestral subsocial life cycle. However, the molecular mechanisms underlying the evolution of reproductive division of labor remain obscure. Using a brain transcriptomics screen, we identified a single gene, insulin-like peptide 2 (ilp2), which is always up-regulated in ant reproductives, likely because they are better nourished than their nonreproductive nestmates. In clonal raider ants (Ooceraea biroi), larval signals inhibit adult reproduction by suppressing ilp2, thus producing a colony reproductive cycle reminiscent of ancestral subsociality. However, increasing ILP2 peptide levels overrides larval suppression, thereby breaking the colony cycle and inducing a stable division of labor. These findings suggest a simple model for the origin of ant eusociality via nutritionally determined reproductive asymmetries potentially amplified by larval signals.
Collapse
Affiliation(s)
- Vikram Chandra
- Laboratory of Social Evolution and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Ingrid Fetter-Pruneda
- Laboratory of Social Evolution and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Peter R Oxley
- Laboratory of Social Evolution and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
- Samuel J. Wood Library, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
| | - Amelia L Ritger
- Laboratory of Social Evolution and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Sean K McKenzie
- Laboratory of Social Evolution and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Romain Libbrecht
- Laboratory of Social Evolution and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Johannes-von-Müller-Weg 6, 55128 Mainz, Germany
| | - Daniel J C Kronauer
- Laboratory of Social Evolution and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| |
Collapse
|
17
|
Villar G, Wolfson MD, Hefetz A, Grozinger CM. Evaluating the Role of Drone-Produced Chemical Signals in Mediating Social Interactions in Honey Bees (Apis mellifera). J Chem Ecol 2017; 44:1-8. [PMID: 29209933 DOI: 10.1007/s10886-017-0912-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 11/09/2017] [Accepted: 11/20/2017] [Indexed: 10/18/2022]
Abstract
Pheromones play a critical role in shaping societies of social insects, including honey bees, Apis mellifera. While diverse functions have been ascribed to queen- and worker-produced compounds, few studies have explored the identity and function of male-produced (drone) compounds. However, several lines of evidence suggest that drones engage in a variety of social interactions inside and outside of the colony. Here we elucidate the chemical composition of extracts of the drone mandibular gland, and test the hypothesis that compounds produced in these glands, or a synthetic blend consisting of the six main compounds, mediate drone social interactions in and out of the colony. Drone mandibular glands primarily produce a blend of saturated, unsaturated and methyl branched fatty acids ranging in chain length from nonanoic to docosanoic acids, and both gland extracts and synthetic blends of these chemicals serve to attract drones outside of the hive, but do not attract workers inside the hive. These studies shed light on the role drones and drone-produced chemicals have on mediating social interactions with other drones and highlight their potential importance in communicating with other castes.
Collapse
Affiliation(s)
- Gabriel Villar
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Megan D Wolfson
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Abraham Hefetz
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978, Ramat Aviv, Israel
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| |
Collapse
|
18
|
Zanni V, Galbraith DA, Annoscia D, Grozinger CM, Nazzi F. Transcriptional signatures of parasitization and markers of colony decline in Varroa-infested honey bees (Apis mellifera). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 87:1-13. [PMID: 28595898 DOI: 10.1016/j.ibmb.2017.06.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/28/2017] [Accepted: 06/02/2017] [Indexed: 06/07/2023]
Abstract
Extensive annual losses of honey bee colonies (Apis mellifera L.) reported in the northern hemisphere represent a global problem for agriculture and biodiversity. The parasitic mite Varroa destructor, in association with deformed wing virus (DWV), plays a key role in this phenomenon, but the underlying mechanisms are still unclear. To elucidate these mechanisms, we analyzed the gene expression profile of uninfested and mite infested bees, under laboratory and field conditions, highlighting the effects of parasitization on the bee's transcriptome under a variety of conditions and scenarios. Parasitization was significantly correlated with higher viral loads. Honey bees exposed to mite infestation exhibited an altered expression of genes related to stress response, immunity, nervous system function, metabolism and behavioural maturation. Additionally, mite infested young bees showed a gene expression profile resembling that of forager bees. To identify potential molecular markers of colony decline, the expression of genes that were commonly regulated across the experiments were subsequently assessed in colonies experiencing increasing mite infestation levels. These studies suggest that PGRP-2, hymenoptaecin, a glucan recognition protein, UNC93 and a p450 cytocrome maybe suitable general biomarkers of Varroa-induced colony decline. Furthermore, the reliability of vitellogenin, a yolk protein previously identified as a good marker of colony survival, was confirmed here.
Collapse
Affiliation(s)
- Virginia Zanni
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università degli Studi di Udine, Via delle Scienze 206, 33100, Udine, Italy.
| | - David A Galbraith
- Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.
| | - Desiderato Annoscia
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università degli Studi di Udine, Via delle Scienze 206, 33100, Udine, Italy.
| | - Christina M Grozinger
- Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.
| | - Francesco Nazzi
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università degli Studi di Udine, Via delle Scienze 206, 33100, Udine, Italy.
| |
Collapse
|
19
|
Villar G, Grozinger CM. Primer effects of the honeybee, Apis mellifera, queen pheromone 9-ODA on drones. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.03.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
20
|
Camiletti AL, Thompson GJ. Drosophila As a Genetically Tractable Model for Social Insect Behavior. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
21
|
Complex patterns of differential expression in candidate master regulatory genes for social behavior in honey bees. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2071-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
22
|
Galbraith DA, Wang Y, Amdam GV, Page RE, Grozinger CM. Reproductive physiology mediates honey bee (Apis mellifera) worker responses to social cues. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-015-1963-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
23
|
Mondet F, Alaux C, Severac D, Rohmer M, Mercer AR, Le Conte Y. Antennae hold a key to Varroa-sensitive hygiene behaviour in honey bees. Sci Rep 2015; 5:10454. [PMID: 26000641 PMCID: PMC4441115 DOI: 10.1038/srep10454] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 04/14/2015] [Indexed: 12/19/2022] Open
Abstract
In honey bees, Varroa sensitive hygiene (VSH) behaviour, which involves the detection and removal of brood parasitised by the mite Varroa destructor, can actively participate in the survival of colonies facing Varroa outbreaks. This study investigated the mechanisms of VSH behaviour, by comparing the antennal transcriptomes of bees that do and do not perform VSH behaviour. Results indicate that antennae likely play a key role in the expression of VSH behaviour. Comparisons with the antennal transcriptome of nurse and forager bees suggest that VSH profile is more similar to that of nurse bees than foragers. Enhanced detection of certain odorants in VSH bees may be predicted from transcriptional patterns, as well as a higher metabolism and antennal motor activity. Interestingly, Deformed wing virus/Varroa destructor virus infections were detected in the antennae, with higher level in non-VSH bees; a putative negative impact of viral infection on bees' ability to display VSH behaviour is proposed. These results bring new perspectives to the understanding of VSH behaviour and the evolution of collective defence by focusing attention on the importance of the peripheral nervous system. In addition, such data might be useful for promoting marker-assisted selection of honey bees that can survive Varroa infestations.
Collapse
Affiliation(s)
- Fanny Mondet
- INRA, UR 406 Abeilles et Environnement, 84914 Avignon Cedex 09, France
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
- AgroParisTech, 75005 Paris, France
| | - Cédric Alaux
- INRA, UR 406 Abeilles et Environnement, 84914 Avignon Cedex 09, France
| | - Dany Severac
- MGX – Montpellier GenomiX, Institut de Génomique Fonctionnelle, 141 rue de la Cardonille, 34094, Montpellier Cedex 05, France
| | - Marine Rohmer
- MGX – Montpellier GenomiX, Institut de Génomique Fonctionnelle, 141 rue de la Cardonille, 34094, Montpellier Cedex 05, France
| | - Alison R. Mercer
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
| | - Yves Le Conte
- INRA, UR 406 Abeilles et Environnement, 84914 Avignon Cedex 09, France
| |
Collapse
|
24
|
Neurophysiological mechanisms underlying sex- and maturation-related variation in pheromone responses in honey bees (Apis mellifera). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2015; 201:731-9. [PMID: 25840687 DOI: 10.1007/s00359-015-1006-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 03/20/2015] [Accepted: 03/23/2015] [Indexed: 10/23/2022]
Abstract
In the honey bee (Apis mellifera), social organization is primarily mediated by pheromones. Queen-produced 9-oxo-2-decenoic acid (9-ODA) functions as both a social and sex pheromone, eliciting attraction in both female workers and male drones, but also affecting other critical aspects of worker physiology and behavior. These effects are also maturation related, as younger workers and sexually mature drones are most receptive to 9-ODA. While changes in the peripheral nervous system drive sex-related differences in sensitivity to 9-ODA, the mechanisms driving maturation-related shifts in receptivity to 9-ODA remain unknown. Here, we investigate the hypothesis that changes at the peripheral nervous system may be mediating plastic responses to 9-ODA by characterizing expression levels of AmOR11 (the olfactory receptor tuned to 9-ODA) and electrophysiological responses to 9-ODA. We find that receptor expression correlates significantly with behavioral receptivity to 9-ODA, with nurses and sexually mature drones exhibiting higher levels of expression than foragers and immature drones, respectively. Electrophysiological responses to 9-ODA were not found to correlate with behavioral receptivity or receptor expression, however. Thus, while receptor expression at the periphery exhibits a level of plasticity that correlates with behavior, the mechanisms driving maturation-dependent responsiveness to 9-ODA appear to function primarily in the central nervous system.
Collapse
|
25
|
Shpigler H, Amsalem E, Huang ZY, Cohen M, Siegel AJ, Hefetz A, Bloch G. Gonadotropic and physiological functions of juvenile hormone in Bumblebee (Bombus terrestris) workers. PLoS One 2014; 9:e100650. [PMID: 24959888 PMCID: PMC4069101 DOI: 10.1371/journal.pone.0100650] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 05/29/2014] [Indexed: 11/21/2022] Open
Abstract
The evolution of advanced sociality in bees is associated with apparent modifications in juvenile hormone (JH) signaling. By contrast to most insects in which JH is a gonadotropin regulating female fertility, in the highly eusocial honey bee (Apis mellifera) JH has lost its gonadotrophic function in adult females, and instead regulates age-related division of labor among worker bees. In order to shed light on the evolution of JH signaling in bees we performed allatectomy and replacement therapies to manipulate JH levels in workers of the "primitively eusocial" bumblebee Bombus terrestris. Allatectomized worker bees showed remarkable reduction in ovarian development, egg laying, Vitellogenin and Krüppel homolog 1 fat body transcript levels, hemolymph Vitellogenin protein abundance, wax secretion, and egg-cell construction. These effects were reverted, at least partially, by treating allatectomized bees with JH-III, the natural JH of bees. Allatectomy also affected the amount of ester component in Dufour's gland secretion, which is thought to convey a social signal relating to worker fertility. These findings provide a strong support for the hypothesis that in contrast to honey bees, JH is a gonadotropin in bumblebees and lend credence to the hypothesis that the evolution of advanced eusociality in honey bees was associated with major modifications in JH signaling.
Collapse
Affiliation(s)
- Hagai Shpigler
- Department of Ecology, Evolution, and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail:
| | - Etya Amsalem
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Zachary Y. Huang
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Mira Cohen
- Department of Ecology, Evolution, and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adam J. Siegel
- Department of Ecology, Evolution, and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Abraham Hefetz
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Guy Bloch
- Department of Ecology, Evolution, and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
26
|
Yamamoto R, Bai H, Dolezal AG, Amdam G, Tatar M. Juvenile hormone regulation of Drosophila aging. BMC Biol 2013; 11:85. [PMID: 23866071 PMCID: PMC3726347 DOI: 10.1186/1741-7007-11-85] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 07/05/2013] [Indexed: 01/01/2023] Open
Abstract
Background Juvenile hormone (JH) has been demonstrated to control adult lifespan in a number of non-model insects where surgical removal of the corpora allata eliminates the hormone’s source. In contrast, little is known about how juvenile hormone affects adult Drosophila melanogaster. Previous work suggests that insulin signaling may modulate Drosophila aging in part through its impact on juvenile hormone titer, but no data yet address whether reduction of juvenile hormone is sufficient to control Drosophila life span. Here we adapt a genetic approach to knock out the corpora allata in adult Drosophila melanogaster and characterize adult life history phenotypes produced by reduction of juvenile hormone. With this system we test potential explanations for how juvenile hormone modulates aging. Results A tissue specific driver inducing an inhibitor of a protein phosphatase was used to ablate the corpora allata while permitting normal development of adult flies. Corpora allata knockout adults had greatly reduced fecundity, inhibited oogenesis, impaired adult fat body development and extended lifespan. Treating these adults with the juvenile hormone analog methoprene restored all traits toward wildtype. Knockout females remained relatively long-lived even when crossed into a genotype that blocked all egg production. Dietary restriction further extended the lifespan of knockout females. In an analysis of expression profiles of knockout females in fertile and sterile backgrounds, about 100 genes changed in response to loss of juvenile hormone independent of reproductive state. Conclusions Reduced juvenile hormone alone is sufficient to extend the lifespan of Drosophila melanogaster. Reduced juvenile hormone limits reproduction by inhibiting the production of yolked eggs, and this may arise because juvenile hormone is required for the post-eclosion development of the vitellogenin-producing adult fat body. Our data do not support a mechanism for juvenile hormone control of longevity simply based on reducing the physiological costs of egg production. Nor does the longevity benefit appear to function through mechanisms by which dietary restriction extends longevity. We identify transcripts that change in response to juvenile hormone independent of reproductive state and suggest these represent somatically expressed genes that could modulate how juvenile hormone controls persistence and longevity.
Collapse
Affiliation(s)
- Rochele Yamamoto
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, USA
| | | | | | | | | |
Collapse
|
27
|
Duportets L, Maria A, Vitecek S, Gadenne C, Debernard S. Steroid hormone signaling is involved in the age-dependent behavioral response to sex pheromone in the adult male moth Agrotis ipsilon. Gen Comp Endocrinol 2013; 186:58-66. [PMID: 23474331 DOI: 10.1016/j.ygcen.2013.02.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 02/19/2013] [Accepted: 02/20/2013] [Indexed: 10/27/2022]
Abstract
In most animals, including insects, male reproduction depends on the detection and processing of female-produced sex pheromones. In the male moth, Agrotis ipsilon, both behavioral response and neuronal sensitivity in the primary olfactory center, the antennal lobe (AL), to female sex pheromone are age- and hormone-dependent. In many animal species, steroids are known to act at the brain level to modulate the responsiveness to sexually relevant chemical cues. We aimed to address the hypothesis that the steroidal system and in particular 20-hydroxyecdysone (20E), the main insect steroid hormone, might also be involved in this olfactory plasticity. Therefore, we first cloned the nuclear ecdysteroid receptor EcR (AipsEcR) and its partner Ultraspiracle (AipsUSP) of A. ipsilon, the expression of which increased concomitantly with age in ALs. Injection of 20E into young sexually immature males led to an increase in both responsiveness to sex pheromone and amount of AipsEcR and AipsUSP in their ALs. Conversely, the behavioral response decreased in older, sexually mature males after injection of cucurbitacin B (CurB), an antagonist of the 20E/EcR/USP complex. Also, the amount of AipsEcR and AipsUSP significantly declined after treatment with CurB. These results suggest that 20E is involved in the expression of sexual behavior via the EcR/USP signaling pathway, probably acting on central pheromone processing in A. ipsilon.
Collapse
Affiliation(s)
- Line Duportets
- UMR 1272, UPMC-INRA, Physiologie de l'Insecte: Signalisation et Communication, Université Paris VI, Bâtiment A, 7 quai Saint Bernard, 75005 Paris, France
| | | | | | | | | |
Collapse
|
28
|
Moda LM, Vieira J, Guimarães Freire AC, Bonatti V, Bomtorin AD, Barchuk AR, Simões ZLP. Nutritionally driven differential gene expression leads to heterochronic brain development in honeybee castes. PLoS One 2013; 8:e64815. [PMID: 23738002 PMCID: PMC3667793 DOI: 10.1371/journal.pone.0064815] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 04/16/2013] [Indexed: 11/19/2022] Open
Abstract
The differential feeding regimes experienced by the queen and worker larvae of the honeybee Apis mellifera shape a complex endocrine response cascade that ultimately gives rise to differences in brain morphologies. Brain development analyzed at the morphological level from the third (L3) through fifth (L5) larval instars revealed an asynchrony between queens and workers. In the feeding phase of the last larval instar (L5F), two well-formed structures, pedunculi and calyces, are identifiable in the mushroom bodies of queens, both of which are not present in workers until a later phase (spinning phase, L5S). Genome-wide expression analyses and normalized transcript expression experiments monitoring specific genes revealed that this differential brain development starts earlier, during L3. Analyzing brains from L3 through L5S1 larvae, we identified 21 genes with caste-specific transcription patterns (e.g., APC-4, GlcAT-P, fax, kr-h1 and shot), which encode proteins that are potentially involved in the development of brain tissues through controlling the cell proliferation rate (APC4, kr-h1) and fasciculation (GlcAT-P, fax, and shot). Shot, whose expression is known to be required for axon extension and cell proliferation, was found to be transcribed at significantly higher levels in L4 queens compared with worker larvae. Moreover, the protein encoded by this gene was immunolocalized to the cytoplasm of cells near the antennal lobe neuropiles and proximal to the Kenyon cells in the brains of L4 queens. In conclusion, during the larval period, the brains of queens are larger and develop more rapidly than workers’ brains, which represents a developmental heterochrony reflecting the effect of the differential feeding regime of the two castes on nervous system development. Furthermore, this differential development is characterized by caste-specific transcriptional profiles of a set of genes, thus pointing to a link between differential nutrition and differential neurogenesis via genes that control cell proliferation and fasciculation.
Collapse
Affiliation(s)
- Lívia Maria Moda
- Departamento de Genética, Universidade de São Paulo-FMRP, Ribeirão Preto, São Paulo, Brazil
- Departamento de Biologia Celular, Tecidual e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| | - Joseana Vieira
- Departamento de Biologia Celular, Tecidual e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| | - Anna Cláudia Guimarães Freire
- Departamento de Biologia Celular, Tecidual e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| | - Vanessa Bonatti
- Departamento de Genética, Universidade de São Paulo-FMRP, Ribeirão Preto, São Paulo, Brazil
- Departamento de Biologia Celular, Tecidual e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| | - Ana Durvalina Bomtorin
- Departamento de Genética, Universidade de São Paulo-FMRP, Ribeirão Preto, São Paulo, Brazil
| | - Angel Roberto Barchuk
- Departamento de Biologia Celular, Tecidual e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
- * E-mail:
| | - Zilá Luz Paulino Simões
- Departamento de Biologia, Universidade de São Paulo-FFCLRP, Ribeirão Preto, São Paulo, Brazil
| |
Collapse
|
29
|
Matsuura K. Multifunctional queen pheromone and maintenance of reproductive harmony in termite colonies. J Chem Ecol 2012; 38:746-54. [PMID: 22623152 DOI: 10.1007/s10886-012-0137-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 05/03/2012] [Accepted: 05/08/2012] [Indexed: 11/26/2022]
Abstract
Pheromones are likely involved in all social activities of social insects including foraging, sexual behavior, defense, nestmate recognition, and caste regulation. Regulation of the number of fertile queens requires communication between reproductive and non-reproductive individuals. Queen-produced pheromones have long been believed to be the main factor inhibiting the differentiation of new reproductive individuals. However, since the discovery more than 50 years ago of the queen honeybee substance that inhibits the queen-rearing behavior of workers, little progress has been made in the chemical identification of inhibitory queen pheromones in other social insects. The recent identification of a termite queen pheromone and subsequent studies have elucidated the multifaceted roles of volatile pheromones, including functions such as a fertility signal, worker attractant, queen-queen communication signal, and antimicrobial agent. The proximate origin and evolutionary parsimony of the termite queen pheromone also are discussed.
Collapse
Affiliation(s)
- Kenji Matsuura
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwakecho, Kyoto, 606-8502, Japan.
| |
Collapse
|
30
|
Orthodenticle and Kruppel homolog 1 regulate Drosophila photoreceptor maturation. Proc Natl Acad Sci U S A 2012; 109:7893-8. [PMID: 22547825 DOI: 10.1073/pnas.1120276109] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neurons present a wide variety of morphologies that are associated with their specialized functions. However, to date very few pathways and factors regulating neuronal maturation, including morphogenesis, have been identified. To address this issue we make use here of the genetically amenable developing fly photoreceptor (PR). Whereas this sensory neuron is specified early during retinal development, its maturation spans several days. During this time, this neuron acquires specialized membrane domains while undergoing extensive polarity remodeling. In this study, we identify a pathway in which the conserved homeobox protein Orthodenticle (Otd) acts together with the ecdysone receptor (EcR) to directly repress the expression of the transcription factor (TF) Kruppel homolog 1 (Kr-h1). We demonstrate that this pathway is not required to promote neuronal specification but is crucial to regulate PR maturation. PR maturation includes the remodeling of the cell's epithelial features and associated apical membrane morphogenesis. Furthermore, we show that hormonal control coordinates PR differentiation and morphogenesis with overall development. This study demonstrates that during PR differentiation, transient repression of Kr-h1 represents a key step regulating neuronal maturation. Down-regulation of Kr-h1 expression has been previously associated with instances of neuronal remodeling in the fly brain. We therefore conclude that repression of this transcription factor represents a key step, enabling remodeling and maturation in a wide variety of neurons.
Collapse
|
31
|
Duportets L, Bozzolan F, Abrieux A, Maria A, Gadenne C, Debernard S. The transcription factor Krüppel homolog 1 is linked to the juvenile hormone-dependent maturation of sexual behavior in the male moth, Agrotis ipsilon. Gen Comp Endocrinol 2012; 176:158-66. [PMID: 22285394 DOI: 10.1016/j.ygcen.2012.01.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/04/2012] [Accepted: 01/07/2012] [Indexed: 12/26/2022]
Abstract
In the male moth, Agrotis ipsilon, the behavioral response and neuronal sensitivity in the primary olfactory center, the antennal lobe (AL), to sex pheromone increase with age and juvenile hormone (JH) biosynthesis. Although JH has been shown to control this age-dependent plasticity, the underlying signaling pathway remains obscure. In this context, we cloned a full cDNA encoding the Krüppel homolog 1 transcription factor (AipsKr-h1) of A. ipsilon, which was found to be predominantly expressed in ALs, where its amount increased concomitantly with age and sex pheromone responses. Conversely, the expression of AipsKr-h1 protein in the antenna was age-independent. Moreover, the administration of JH in immature males or fluvastatin, an inhibitor of JH biosynthesis, in mature males induced an increase or a decline of the AipsKr-h1 protein level in ALs, respectively. This effect was suppressed with a combined injection of fluvastatin and JH. Our results showed that Aipskr-h1 is a JH-upregulated gene that might mediate JH action on central pheromone processing, modulating sexual behavior in A. ipsilon.
Collapse
Affiliation(s)
- Line Duportets
- UMR 1272, UPMC-INRA, Physiologie de l'Insecte: Signalisation et Communication, Université Paris VI, Bâtiment A, 7 quai Saint Bernard, 75005 Paris, France
| | | | | | | | | | | |
Collapse
|
32
|
Ament SA, Chan QW, Wheeler MM, Nixon SE, Johnson SP, Rodriguez-Zas SL, Foster LJ, Robinson GE. Mechanisms of stable lipid loss in a social insect. ACTA ACUST UNITED AC 2012; 214:3808-21. [PMID: 22031746 DOI: 10.1242/jeb.060244] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Worker honey bees undergo a socially regulated, highly stable lipid loss as part of their behavioral maturation. We used large-scale transcriptomic and proteomic experiments, physiological experiments and RNA interference to explore the mechanistic basis for this lipid loss. Lipid loss was associated with thousands of gene expression changes in abdominal fat bodies. Many of these genes were also regulated in young bees by nutrition during an initial period of lipid gain. Surprisingly, in older bees, which is when maximum lipid loss occurs, diet played less of a role in regulating fat body gene expression for components of evolutionarily conserved nutrition-related endocrine systems involving insulin and juvenile hormone signaling. By contrast, fat body gene expression in older bees was regulated more strongly by evolutionarily novel regulatory factors, queen mandibular pheromone (a honey bee-specific social signal) and vitellogenin (a conserved yolk protein that has evolved novel, maturation-related functions in the bee), independent of nutrition. These results demonstrate that conserved molecular pathways can be manipulated to achieve stable lipid loss through evolutionarily novel regulatory processes.
Collapse
Affiliation(s)
- Seth A Ament
- Neuroscience Program, University of Illinois, Urbana, IL 61801, USA
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Bloch G, Grozinger CM. Social molecular pathways and the evolution of bee societies. Philos Trans R Soc Lond B Biol Sci 2011; 366:2155-70. [PMID: 21690132 PMCID: PMC3130366 DOI: 10.1098/rstb.2010.0346] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bees provide an excellent model with which to study the neuronal and molecular modifications associated with the evolution of sociality because relatively closely related species differ profoundly in social behaviour, from solitary to highly social. The recent development of powerful genomic tools and resources has set the stage for studying the social behaviour of bees in molecular terms. We review 'ground plan' and 'genetic toolkit' models which hypothesize that discrete pathways or sets of genes that regulate fundamental behavioural and physiological processes in solitary species have been co-opted to regulate complex social behaviours in social species. We further develop these models and propose that these conserved pathways and genes may be incorporated into 'social pathways', which consist of relatively independent modules involved in social signal detection, integration and processing within the nervous and endocrine systems, and subsequent behavioural outputs. Modifications within modules or in their connections result in the evolution of novel behavioural patterns. We describe how the evolution of pheromonal regulation of social pathways may lead to the expression of behaviour under new social contexts, and review plasticity in circadian rhythms as an example for a social pathway with a modular structure.
Collapse
Affiliation(s)
- Guy Bloch
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
| | | |
Collapse
|
34
|
Effects of instrumental insemination and insemination quantity on Dufour's gland chemical profiles and vitellogenin expression in honey bee queens (Apis mellifera). J Chem Ecol 2011; 37:1027-36. [PMID: 21786084 DOI: 10.1007/s10886-011-9999-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 05/18/2011] [Accepted: 07/10/2011] [Indexed: 10/18/2022]
Abstract
Honey bee queens (Apis mellifera) mate in their early adult lives with a variable number of males (drones). Mating stimulates dramatic changes in queen behavior, physiology, gene expression, and pheromone production. Here, we used virgin, single drone- (SDI), and multi-drone- (MDI) inseminated queens to study the effects of instrumental insemination and insemination quantity on the pheromone profiles of the Dufour's gland, and the expression of the egg-yolk protein, vitellogenin, in the fat body. Age, environmental conditions, and genetic background of the queens were standardized to specifically characterize the effects of these treatments. Our data demonstrate that insemination and insemination quantity significantly affect the chemical profiles of the Dufour's gland secretion. Moreover, workers were more attracted to Dufour's gland extract from inseminated queens compared to virgins, and to the extract of MDI queens compared to extract of SDI queens. However, while there were differences in the amounts of some esters between MDI queens and the other groups, it appears that the differences in behavioral responses were elicited by subtle changes in the overall chemical profiles rather than dramatic changes in specific individual chemicals. We also found a decrease in vitellogenin gene expression in the fat body of the MDI queens, which is negatively correlated with the quantities of Dufour's gland content. The possible explanations of this reduction are discussed.
Collapse
|
35
|
Fussnecker BL, McKenzie AM, Grozinger CM. cGMP modulates responses to queen mandibular pheromone in worker honey bees. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2011; 197:939-48. [PMID: 21626397 DOI: 10.1007/s00359-011-0654-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 05/11/2011] [Accepted: 05/14/2011] [Indexed: 11/26/2022]
Abstract
Responses to social cues, such as pheromones, can be modified by genotype, physiology, or environmental context. Honey bee queens produce a pheromone (queen mandibular pheromone; QMP) which regulates aspects of worker bee behavior and physiology. Forager bees are less responsive to QMP than young bees engaged in brood care, suggesting that physiological changes associated with behavioral maturation modulate response to this pheromone. Since 3',5'-cyclic guanosine monophosphate (cGMP) is a major regulator of behavioral maturation in workers, we examined its role in modulating worker responses to QMP. Treatment with a cGMP analog resulted in significant reductions in both behavioral and physiological responses to QMP in young caged workers. Treatment significantly reduced attraction to QMP and inhibited the QMP-mediated increase in vitellogenin RNA levels in the fat bodies of worker bees. Genome-wide analysis of brain gene expression patterns demonstrated that cGMP has a larger effect on expression levels than QMP, and that QMP has specific effects in the presence of cGMP, suggesting that some responses to QMP may be dependent on an individual bees' physiological state. Our data suggest that cGMP-mediated processes play a role in modulating responses to QMP in honey bees at the behavioral, physiological, and molecular levels.
Collapse
Affiliation(s)
- Brendon L Fussnecker
- Department of Genetics, North Carolina State University, Box 7614, Raleigh 27695, USA.
| | | | | |
Collapse
|
36
|
Ihle KE, Page RE, Frederick K, Fondrk MK, Amdam GV. Genotype effect on regulation of behaviour by vitellogenin supports reproductive origin of honeybee foraging bias. Anim Behav 2010; 79:1001-1006. [PMID: 20454635 DOI: 10.1016/j.anbehav.2010.02.009] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In honeybee colonies, food collection is performed by a group of mostly sterile females called workers. After an initial nest phase, workers begin foraging for nectar and pollen, but tend to bias their collection towards one or the other. The foraging choice of honeybees is influenced by vitellogenin (vg), an egg-yolk precursor protein that is expressed although workers typically do not lay eggs. The forager reproductive ground plan hypothesis (RGPH) proposes an evolutionary path in which the behavioural bias toward collecting nectar or pollen on foraging trips is influenced by variation in reproductive physiology, such as hormone levels and vg gene expression. Recently, the connections between vg and foraging behaviour were challenged by Oldroyd and Beekman (2008), who concluded from their study that the ovary, and especially vg, played no role in foraging behaviour of bees. We address their challenge directly by manipulating vg expression by RNA interference- (RNAi) mediated gene knockdown in two honeybee genotypes with different foraging behaviour and reproductive physiology. We show that the effect of vg on the food-loading decisions of the workers occurs only in the genotype where timing of foraging onset (by age) is also sensitive to vg levels. In the second genotype, changing vg levels do not affect foraging onset or bias. The effect of vg on workers' age at foraging onset is explained by the well-supported double repressor hypothesis (DHR), which describes a mutually inhibitory relationship between vg and juvenile hormone (JH) - an endocrine factor that influences development, reproduction, and behaviour in many insects. These results support the RGPH and demonstrate how it intersects with an established mechanism of honeybee behavioural control.
Collapse
Affiliation(s)
- Kate E Ihle
- School of Life Sciences, Arizona State University, Tempe
| | | | | | | | | |
Collapse
|
37
|
Shpigler H, Patch HM, Cohen M, Fan Y, Grozinger CM, Bloch G. The transcription factor Krüppel homolog 1 is linked to hormone mediated social organization in bees. BMC Evol Biol 2010; 10:120. [PMID: 20429952 PMCID: PMC2876159 DOI: 10.1186/1471-2148-10-120] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 04/30/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Regulation of worker behavior by dominant queens or workers is a hallmark of insect societies, but the underlying molecular mechanisms and their evolutionary conservation are not well understood. Honey bee and bumble bee colonies consist of a single reproductive queen and facultatively sterile workers. The queens' influences on the workers are mediated largely via inhibition of juvenile hormone titers, which affect division of labor in honey bees and worker reproduction in bumble bees. Studies in honey bees identified a transcription factor, Krüppel-homolog 1 (Kr-h1), whose expression in worker brains is significantly downregulated in the presence of a queen or queen pheromone and higher in forager bees, making this gene an ideal candidate for examining the evolutionary conservation of socially regulated pathways in Hymenoptera. RESULTS In contrast to honey bees, bumble bees foragers do not have higher Kr-h1 levels relative to nurses: in one of three colonies levels were similar in nurses and foragers, and in two colonies levels were higher in nurses. Similarly to honey bees, brain Kr-h1 levels were significantly downregulated in the presence versus absence of a queen. Furthermore, in small queenless groups, Kr-h1 levels were downregulated in subordinate workers with undeveloped ovaries relative to dominant individuals with active ovaries. Brain Kr-h1 levels were upregulated by juvenile hormone treatment relative to a vehicle control. Finally, phylogenetic analysis indicates that KR-H1 orthologs are presence across insect orders. Though this protein is highly conserved between honey bees and bumble bees, there are significant differences between orthologs of insects from different orders. CONCLUSIONS Our results suggest that Kr-h1 is associated with juvenile hormone mediated regulation of reproduction in bumble bees. The expression of this transcription factor is inhibited by the queen and associated with endocrine mediated regulation of social organization in two species of bees. Thus, KR-H1 may transcriptionally regulate a conserved genetic module that is part of a pathway that has been co-opted to function in social behavior, and adjusts the behavior of workers to their social environmental context.
Collapse
Affiliation(s)
- Hagai Shpigler
- Department of Evolution, Systematics, and Ecology, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Harland M Patch
- Department of Entomology and Genetics, North Carolina State University, Raleigh, NC, USA
- Department of Entomology, Center for Pollinator Research, Center for Chemical Ecology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Mira Cohen
- Department of Evolution, Systematics, and Ecology, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yongliang Fan
- Department of Entomology and Genetics, North Carolina State University, Raleigh, NC, USA
- Syngenta Biotechnology, Incorporated; Research Triangle Park, NC, USA
| | - Christina M Grozinger
- Department of Entomology and Genetics, North Carolina State University, Raleigh, NC, USA
- Department of Entomology, Center for Pollinator Research, Center for Chemical Ecology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Guy Bloch
- Department of Evolution, Systematics, and Ecology, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
38
|
Kocher SD, Ayroles JF, Stone EA, Grozinger CM. Individual variation in pheromone response correlates with reproductive traits and brain gene expression in worker honey bees. PLoS One 2010; 5:e9116. [PMID: 20161742 PMCID: PMC2817734 DOI: 10.1371/journal.pone.0009116] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 01/14/2010] [Indexed: 11/23/2022] Open
Abstract
Background Variation in individual behavior within social groups can affect the fitness of the group as well as the individual, and can be caused by a combination of genetic and environmental factors. However, the molecular factors associated with individual variation in social behavior remain relatively unexplored. We used honey bees (Apis mellifera) as a model to examine differences in socially-regulated behavior among individual workers, and used transcriptional profiling to determine if specific gene expression patterns are associated with these individual differences. In honey bees, the reproductive queen produces a pheromonal signal that regulates many aspects of worker behavior and physiology and maintains colony organization. Methodology/Principal Findings Here, we demonstrate that there is substantial natural variation in individual worker attraction to queen pheromone (QMP). Furthermore, worker attraction is negatively correlated with ovariole number—a trait associated with reproductive potential in workers. We identified transcriptional differences in the adult brain associated with individual worker attraction to QMP, and identified hundreds of transcripts that are organized into statistically-correlated gene networks and associated with this response. Conclusions/Significance Our studies demonstrate that there is substantial variation in worker attraction to QMP among individuals, and that this variation is linked with specific differences in physiology and brain gene expression patterns. This variation in individual response thresholds may reveal underlying variation in queen-worker reproductive conflict, and may mediate colony function and productivity by creating variation in individual task performance.
Collapse
Affiliation(s)
- Sarah D. Kocher
- Department of Genetics, North Carolina State University, Raleigh, North Carolina, United States of America
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail: (SDK); (CMG)
| | - Julien F. Ayroles
- Department of Genetics, North Carolina State University, Raleigh, North Carolina, United States of America
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Eric A. Stone
- Department of Genetics, North Carolina State University, Raleigh, North Carolina, United States of America
- Department of Statistics, North Carolina State University, Raleigh, North Carolina, United States of America
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Christina M. Grozinger
- Department of Genetics, North Carolina State University, Raleigh, North Carolina, United States of America
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail: (SDK); (CMG)
| |
Collapse
|
39
|
Alaux C, Maisonnasse A, Le Conte Y. Pheromones in a superorganism: from gene to social regulation. VITAMINS AND HORMONES 2010; 83:401-23. [PMID: 20831956 DOI: 10.1016/s0083-6729(10)83017-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Analogous to the importance of hormones in controlling organism homoeostasis, pheromones play a major role in the regulation of group homoeostasis at the social level. In social insects, pheromones coordinate the association of "unitary" organisms into a coherent social unit or so called "superorganism." For many years, honey bees have been a convincing model for studying pheromone regulation of social life. In addition, with the recent sequencing of its genome, a global view of pheromone communication is starting to emerge, and it is now possible to decipher this complex chemical language from the molecular to the social level. We review here the different pheromones regulating the main biological functions of the superorganism and detail their respective action on the genome, physiology and behavior of nestmates. Finally, we suggest some future research that may improve our understanding of the remarkably rich syntax of pheromone communication at the social level.
Collapse
Affiliation(s)
- C Alaux
- INRA, UMR 406 Abeilles et Environnement, Site Agroparc, Domaine Saint-Paul, Avignon, France
| | | | | |
Collapse
|
40
|
Cuticular hydrocarbon profiles indicate reproductive status in the termite Zootermopsis nevadensis. Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0807-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
41
|
Abstract
Goldfish (Carassius auratus) use reproductive hormones as endocrine signals to synchronize sexual behavior with gamete maturation and as exogenous signals (pheromones) to mediate spawning interactions between conspecifics. We examined the differential effects of two hormonal pheromones, prostaglandin F(2alpha) (PGF(2alpha)) and 17alpha,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P) on neurogenesis, neurotransmission, and neuronal activities, and on plasma androstenedione (AD) levels. Exposure to waterborne PGF(2alpha) induced a multitude of changes in male goldfish brain. Histological examination indicated an increase in the number of dividing cells in male diencephalon (p < 0.05, Kruskal-Wallis test). Real-time quantitative PCR tests showed elevated levels of transcripts for the salmon gonadotropin-releasing hormone (GnRH) in the male telencephalon and cerebellum (p < 0.005, one-way ANOVA) and for ChAT (choline acetyltransferase) in the male vagal lobe and the brainstem underneath the vagal lobe (p < 0.05, one-way ANOVA). Therefore, PGF(2alpha) seemed to modulate male brain plasticity that coincided with behavioral changes during spawning season. Exposure to waterborne 17,20beta-P, however, increased circulatory levels of immunoreactive AD in males and the transcripts of androgen receptor and cGnRH-II (chicken-II GnRH) in the female cerebellum (p < 0.05, one-way ANOVA). PGF(2alpha) and 17,20beta-P thereby seemed to act through distinct pathways to elicit different responses in the neuroendocrine system. This is the first finding that links a specific pheromone molecule (PGF(2alpha)) to neurogenesis in a vertebrate animal.
Collapse
|
42
|
Alaux C, Le Conte Y, Adams HA, Rodriguez-Zas S, Grozinger CM, Sinha S, Robinson GE. Regulation of brain gene expression in honey bees by brood pheromone. GENES BRAIN AND BEHAVIOR 2009; 8:309-19. [PMID: 19220482 DOI: 10.1111/j.1601-183x.2009.00480.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- C Alaux
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | | | | | | | | | | | | |
Collapse
|
43
|
Krüppel homolog 1, an early juvenile hormone-response gene downstream of Methoprene-tolerant, mediates its anti-metamorphic action in the red flour beetle Tribolium castaneum. Dev Biol 2009; 325:341-50. [DOI: 10.1016/j.ydbio.2008.10.016] [Citation(s) in RCA: 245] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 10/02/2008] [Accepted: 10/06/2008] [Indexed: 11/15/2022]
|
44
|
Velarde RA, Robinson GE, Fahrbach SE. Coordinated responses to developmental hormones in the Kenyon cells of the adult worker honey bee brain (Apis mellifera L.). JOURNAL OF INSECT PHYSIOLOGY 2009; 55:59-69. [PMID: 19013465 DOI: 10.1016/j.jinsphys.2008.10.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 10/14/2008] [Accepted: 10/15/2008] [Indexed: 05/27/2023]
Abstract
The brains of experienced forager honey bees exhibit predictable changes in structure, including significant growth of the neuropil of the mushroom bodies. In vertebrates, members of the superfamily of nuclear receptors function as key regulators of neuronal structure. The adult insect brain expresses many members of the nuclear receptor superfamily, suggesting that insect neurons are also likely important targets of developmental hormones. The actions of developmental hormones (the ecdysteroids and the juvenile hormones) in insects have been primarily explored in the contexts of metamorphosis and vitellogenesis. The cascade of gene expression activated by 20-hydroxyecdysone and modulated by juvenile hormone is strikingly conserved in these different physiological contexts. We used quantitative RT-PCR to measure, in the mushroom bodies of the adult worker honey bee brain, relative mRNA abundances of key members of the nuclear receptor superfamily (EcR, USP, E75, Ftz-f1, and Hr3) that participate in the metamorphosis/vitellogenesis cascade. We measured responses to endogenous peaks of hormones experienced early in adult life and to exogenous hormones. Our studies demonstrate that a population of adult insect neurons is responsive to endocrine signals through the use of conserved portions of the canonical ecdysteroid transcriptional cascade previously defined for metamorphosis and vitellogenesis.
Collapse
Affiliation(s)
- Rodrigo A Velarde
- Department of Biology, Wake Forest University, Box 7325, Winston-Salem, NC 27109, USA.
| | | | | |
Collapse
|
45
|
Richard FJ, Aubert A, Grozinger CM. Modulation of social interactions by immune stimulation in honey bee, Apis mellifera, workers. BMC Biol 2008; 6:50. [PMID: 19014614 PMCID: PMC2596086 DOI: 10.1186/1741-7007-6-50] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 11/17/2008] [Indexed: 11/14/2022] Open
Abstract
Background Immune response pathways have been relatively well-conserved across animal species, with similar systems in both mammals and invertebrates. Interestingly, honey bees have substantially reduced numbers of genes associated with immune function compared with solitary insect species. However, social species such as honey bees provide an excellent environment for pathogen or parasite transmission with controlled environmental conditions in the hive, high population densities, and frequent interactions. This suggests that honey bees may have developed complementary mechanisms, such as behavioral modifications, to deal with disease. Results Here, we demonstrate that activation of the immune system in honey bees (using bacterial lipopolysaccharides as a non-replicative pathogen) alters the social responses of healthy nestmates toward the treated individuals. Furthermore, treated individuals expressed significant differences in overall cuticular hydrocarbon profiles compared with controls. Finally, coating healthy individuals with extracts containing cuticular hydrocarbons of immunostimulated individuals significantly increased the agonistic responses of nestmates. Conclusion Since cuticular hydrocarbons play a critical role in nestmate recognition and other social interactions in a wide variety of insect species, modulation of such chemical profiles by the activation of the immune system could play a crucial role in the social regulation of pathogen dissemination within the colony.
Collapse
Affiliation(s)
- F-J Richard
- Department of Entomology, WM Keck Center for Behavioral Biology, Gardner Hall, North Carolina State University, Raleigh, NC 27695, USA.
| | | | | |
Collapse
|
46
|
Hewes RS. The buzz on fly neuronal remodeling. Trends Endocrinol Metab 2008; 19:317-23. [PMID: 18805704 DOI: 10.1016/j.tem.2008.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 07/28/2008] [Accepted: 07/29/2008] [Indexed: 10/21/2022]
Abstract
Hormone-dependent rewiring of axons and dendrites is a conserved feature of nervous system development and plasticity. During metamorphosis in insects, steroid hormones (the ecdysteroids) and terpenoid hormones (the juvenile hormones) regulate extensive remodeling of the nervous system. These changes retool the nervous system for new behavioral and physiological functions that are required for the adult stage of the life cycle. In honey bees and other highly social insects, hormones also regulate behavioral changes and neuronal plasticity associated with transitions between social caste roles. This review focuses on recent work in fruit flies and honey bees that reveals hormonal and molecular mechanisms underlying metamorphic and caste-dependent neuronal remodeling, with specific emphasis on the role of Krüppel homolog 1.
Collapse
Affiliation(s)
- Randall S Hewes
- Department of Zoology, University of Oklahoma, Norman, OK 73019, USA.
| |
Collapse
|
47
|
Fussnecker B, Grozinger C. Dissecting the role of Kr-h1 brain gene expression in foraging behavior in honey bees (Apis mellifera). INSECT MOLECULAR BIOLOGY 2008; 17:515-522. [PMID: 18715264 DOI: 10.1111/j.1365-2583.2008.00819.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Expression of Krüppel homolog-1 (Kr-h1) in the honey bee brain is strongly associated with foraging behavior. We performed a series of studies to determine if Kr-h1 expression correlates with specific aspects of foraging. We found that Kr-h1 expression is unaffected by flight experience in male bees. Expression was unaffected by behavioral reversion of workers from foraging to brood care, suggesting that expression is not associated with the active performance of foraging, but rather with stable physiological changes. Kr-h1 expression is increased by cGMP treatment in workers, and the Kr-h1 promoter contains a conserved potential cGMP response element. Since cGMP treatment causes precocious foraging, our results suggest that Kr-h1 expression is associated with cGMP-mediated changes in the brain that occur early in the transition to foraging behavior.
Collapse
Affiliation(s)
- B Fussnecker
- Department of Genetics, and W.M. Keck Center for Behavioral Biology, 1566A Gardner Hall, MC 7613, North Carolina State University, Raleigh, NC 27695, USA.
| | | |
Collapse
|
48
|
Colony nutritional status modulates worker responses to foraging recruitment pheromone in the bumblebee Bombus terrestris. Behav Ecol Sociobiol 2008. [DOI: 10.1007/s00265-008-0623-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
49
|
Pheromonal regulation of starvation resistance in honey bee workers (Apis mellifera). Naturwissenschaften 2008; 95:723-9. [PMID: 18414825 DOI: 10.1007/s00114-008-0378-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 03/01/2008] [Accepted: 03/16/2008] [Indexed: 10/22/2022]
Abstract
Most animals can modulate nutrient storage pathways according to changing environmental conditions, but in honey bees nutrient storage is also modulated according to changing behavioral tasks within a colony. Specifically, bees involved in brood care (nurses) have higher lipid stores in their abdominal fat bodies than forager bees. Pheromone communication plays an important role in regulating honey bee behavior and physiology. In particular, queen mandibular pheromone (QMP) slows the transition from nursing to foraging. We tested the effects of QMP exposure on starvation resistance, lipid storage, and gene expression in the fat bodies of worker bees. We found that indeed QMP-treated bees survived much longer compared to control bees when starved and also had higher lipid levels. Expression of vitellogenin RNA, which encodes a yolk protein that is found at higher levels in nurses than foragers, was also higher in the fat bodies of QMP-treated bees. No differences were observed in expression of genes involved in insulin signaling pathways, which are associated with nutrient storage and metabolism in a variety of species; thus, other mechanisms may be involved in increasing the lipid stores. These studies demonstrate that pheromone exposure can modify nutrient storage pathways and fat body gene expression in honey bees and suggest that chemical communication and social interactions play an important role in altering metabolic pathways.
Collapse
|
50
|
Shi L, Lin S, Grinberg Y, Beck Y, Grozinger CM, Robinson GE, Lee T. Roles of Drosophila Kruppel-homolog 1 in neuronal morphogenesis. Dev Neurobiol 2007; 67:1614-26. [PMID: 17562531 DOI: 10.1002/dneu.20537] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The molecular mechanisms underlying remodeling of neural networks remain largely unknown. In Drosophila, widespread neural remodeling occurs during metamorphosis, and is regulated by ecdysone. Kruppel-homolog 1 (Kr-h1) is a zinc finger transcription factor known to play a role in orchestrating ecdysone-regulated transcriptional pathways and, furthermore, implicated in governing axon morphogenesis. Interestingly, in honey bee workers, neural expression of the Apis mellifera homolog of Kr-h1 is enhanced during their transition to foraging behavior when there is increased neurite outgrowth, branching, and synapse formation. Here, we assessed the role(s) of KR-H1 in Drosophila neuronal remodeling and morphology. We characterized the effect of Kr-h1 expression on neuronal morphology through Drosophila larval, pupal, and adult stages. Increased expression of Kr-h1 led to reduced branching in individual neurons and gross morphological changes in the mushroom bodies (MBs), while knocking down Kr-h1 did not produce any obvious changes in neural morphology. Drosophila Kr-h1 is normally expressed when MB neurons do not undergo active morphogenesis, suggesting that it may play a role in inhibiting morphogenesis. Further, loss of endogenous KR-H1 enhanced the neuronal morphogenesis that is otherwise delayed due to defective TGF-beta signaling. However, loss of KR-H1 alone did not affect neuronal morphogenesis. In addition, Kr-h1 expression remains strongly linked to ecdysone-regulated pathways: Kr-h1 expression is regulated by usp, which dimerizes to the ecdysone receptor, and Kr-h1 expression is essential for proper patterning of the ecdysone receptor isoforms in the late larval central nervous system. Thus, although KR-H1 has a potential for modulating neuronal morphogenesis, it appears physiologically involved in coordinating general ecdysone signaling.
Collapse
Affiliation(s)
- Lei Shi
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | | | | | | | | | | | | |
Collapse
|