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Hayes AM, Worthington AM, Lavine M, Lavine L. Phenotypically plastic responses to environmental variation are more complex than life history theory predicts. Evolution 2024; 78:1486-1498. [PMID: 38761110 DOI: 10.1093/evolut/qpae077] [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: 04/21/2023] [Revised: 04/01/2024] [Accepted: 05/16/2024] [Indexed: 05/20/2024]
Abstract
For insects that exhibit wing polyphenic development, abiotic and biotic signals dictate the adult wing morphology of the insect in an adaptive manner such that in stressful environments the formation of a flight-capable morph is favored and in low-stress environments, a flightless morph is favored. While there is a relatively large amount known about the environmental cues that dictate morph formation in wing polyphenic hemipterans like planthoppers and aphids, whether those cues dictate the same morphs in non-hemipteran (i.e., cricket) wing polyphenic species has not been explicitly investigated. To experimentally test the generality of environmental cue determination of wing polyphenism across taxa with diverse life histories, in this study, we tested the importance of food quantity, parasitic infection, and tactile cues on wing morph determination in the wing polyphenic sand field cricket, Gryllus firmus. Our results also show that certain stress cues, such as severe diet quantity limitation and parasitic infection, actually led to an increase in the production of flightless morph. Based on these findings, our results suggest that physiological and genetic constraints are important to an organism's ability to respond to environmental variation in an adaptive manner beyond simple life history trade-offs.
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Affiliation(s)
- Abigail M Hayes
- Department of Entomology, Washington State University, Pullman, WA, United States
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Mansfield, CT, United States
| | - Amy M Worthington
- Department of Biology, Creighton University, Omaha, NE, United States
| | - Mark Lavine
- Department of Entomology, Washington State University, Pullman, WA, United States
| | - Laura Lavine
- Department of Entomology, Washington State University, Pullman, WA, United States
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2
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Stahlschmidt ZR, Joura H, Makarem JR, Sun JL. Hot and scared: how do heatwaves and predation risk impact resource acquisition and allocation? Biol Lett 2024; 20:20240009. [PMID: 38653332 PMCID: PMC11040502 DOI: 10.1098/rsbl.2024.0009] [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: 01/08/2024] [Revised: 02/12/2024] [Accepted: 03/05/2024] [Indexed: 04/25/2024] Open
Abstract
Heatwaves are increasingly prevalent and can constrain investment into important life-history traits. In addition to heatwaves, animals regularly encounter threats from other organisms in their environments, such as predators. The combination of these two environmental factors introduces a decision-making conflict-heat exposure requires more food intake to fuel investment into fitness-related traits, but foraging in the presence of predators increases the threat of mortality. Thus, we used female variable field crickets (Gryllus lineaticeps) to investigate the effects of heatwaves in conjunction with predation risk (exposed food and water sources, and exposure to scent from black widow spiders, Latrodectus hesperus) on resource acquisition (food intake) and allocation (investment into ovarian and somatic tissues). A simulated heatwave increased food intake and the allocation of resources to reproductive investment. Crickets exposed to high predation risk reduced food intake, but they were able to maintain reproductive investment at an expense to investment into somatic tissue. Thus, heatwaves and predation risk deprioritized investment into self-maintenance, which may impair key physiological processes. This study is an important step towards understanding the ecology of fear in a warming world.
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Affiliation(s)
| | - Harnoor Joura
- Department of Biological Sciences, University of the Pacific, Stockton, CA, USA
| | - Jenna R. Makarem
- Department of Biological Sciences, University of the Pacific, Stockton, CA, USA
| | - Jodie L. Sun
- Department of Biological Sciences, University of the Pacific, Stockton, CA, USA
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3
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Cheng S, Jacobs CGC, Mogollón Pérez EA, Chen D, van de Sanden JT, Bretscher KM, Verweij F, Bosman JS, Hackmann A, Merks RMH, van den Heuvel J, van der Zee M. A life-history allele of large effect shortens developmental time in a wild insect population. Nat Ecol Evol 2024; 8:70-82. [PMID: 37957313 DOI: 10.1038/s41559-023-02246-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/04/2023] [Indexed: 11/15/2023]
Abstract
Developmental time is a key life-history trait with large effects on Darwinian fitness. In many insects, developmental time is currently under strong selection to minimize ecological mismatches in seasonal timing induced by climate change. The genetic basis of responses to such selection, however, is poorly understood. To address this problem, we set up a long-term evolve-and-resequence experiment in the beetle Tribolium castaneum and selected replicate, outbred populations for fast or slow embryonic development. The response to this selection was substantial and embryonic developmental timing of the selection lines started to diverge during dorsal closure. Pooled whole-genome resequencing, gene expression analysis and an RNAi screen pinpoint a 222 bp deletion containing binding sites for Broad and Tramtrack upstream of the ecdysone degrading enzyme Cyp18a1 as a main target of selection. Using CRISPR/Cas9 to reconstruct this allele in the homogenous genetic background of a laboratory strain, we unravel how this single deletion advances the embryonic ecdysone peak inducing dorsal closure and show that this allele accelerates larval development but causes a trade-off with fecundity. Our study uncovers a life-history allele of large effect and reveals the evolvability of developmental time in a natural insect population.
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Affiliation(s)
- Shixiong Cheng
- Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Chris G C Jacobs
- Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Elisa A Mogollón Pérez
- Institute of Biology, Leiden University, Leiden, the Netherlands
- Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Daipeng Chen
- Mathematical Institute, Leiden University, Leiden, the Netherlands
| | - Joep T van de Sanden
- Institute of Biology, Leiden University, Leiden, the Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
| | | | - Femke Verweij
- Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Jelle S Bosman
- Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Amke Hackmann
- Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Roeland M H Merks
- Institute of Biology, Leiden University, Leiden, the Netherlands
- Mathematical Institute, Leiden University, Leiden, the Netherlands
| | - Joost van den Heuvel
- Laboratory of Genetics, Wageningen University and Research, Wageningen, the Netherlands
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4
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Ren YS, Zhang B, Zeng Y, Zhu DH. Effects of Flight on Reproductive Development in Long-Winged Female Crickets ( Velarifictorus aspersus Walker; Orthoptera: Gryllidae) with Differences in Flight Behavior. INSECTS 2023; 14:79. [PMID: 36662007 PMCID: PMC9861251 DOI: 10.3390/insects14010079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
A trade-off between the capacity for flight and reproduction has been documented extensively in wing polymorphic female insects, thereby supporting the possible fitness gain due to flightlessness. However, most of these studies were conducted without considering the effect of flight behavior. In the present study, we assessed the flight duration by long-winged (LW) females in the cricket species Velarifictorus aspersus on different days after adult emergence and examined the effect of flight on ovarian development in LW females with different flight capacities. Our results showed that the flight capacity increased with age and peaked after 5 days. In addition, the flight capacity varied among individuals, where most LW females could only take short flights (sustained flight time < 10 min) and only a few individuals could take long flights (sustained flight time > 20 min). In LW female crickets demonstrating only short flights, repeated flying for 30 or 60 min significantly promoted reproductive development. However, in those capable of long flights, reproductive development was affected only after a flight of 60 min. The flight muscles degraded after the start of rapid reproduction in those with both short and long flights. Our results indicated that the critical flight time for switching from flight to reproduction varies among LW V. aspersus female crickets with polymorphic flight behavior.
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5
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Stahlschmidt ZR, Whitlock J, Vo C, Evalen P, D B. Pesticides in a warmer world: Effects of glyphosate and warming across insect life stages. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119508. [PMID: 35605834 DOI: 10.1016/j.envpol.2022.119508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/02/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Glyphosate (GLY) is a broad-spectrum herbicide that is the most commonly applied pesticide in terrestrial ecosystems in the U.S. and, potentially, worldwide. However, the combined effects of warming associated with climate change and exposure to GLY and GLY-based formulations (GBFs) on terrestrial animals are poorly understood. Animals progress through several life stages (e.g., embryonic, larval, and juvenile stages) that may exhibit different sensitivities to stressors. Therefore, we factorially manipulated temperature and GLY/GBF exposure in the variable field cricket (Gryllus lineaticeps) during two life stages-nymphal development and adulthood-and examined key animal traits, such as developmental rate, body size, food consumption, reproductive investment, and lifespan. A thermal environment simulating future climate warming obligated several costs to fitness-related traits. For example, warming experienced during nymphal development reduced survival, adult body mass and size, and investment into flight capacity and reproduction. Warming experienced by adults reduced lifespan and growth rate. Alternatively, the effects of GBF exposure were more subtle, often context-dependent (e.g., effects were only detected in one sex or temperature regime), and were stronger during adult exposure relative to exposure during development. There was evidence of additive costs of warming and GBF exposure to rates of feeding and growth in adults. Yet, the negative effect of GBF exposure to adult lifespan did not occur in warming conditions, suggesting that ongoing climate change may obscure some of the costs of GBFs to non-target organisms. The effects of GLY alone (i.e., in the absence of proprietary surfactants found in commercial formulations) were non-existent. Animals will be increasingly exposed to warming and GBFs, and our results indicate that GBF exposure and warming can entail additive costs for an animal taxon (insects) that plays critical roles in terrestrial ecosystems.
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Affiliation(s)
| | - J Whitlock
- University of the Pacific, Stockton, CA, 95211, USA
| | - C Vo
- University of the Pacific, Stockton, CA, 95211, USA
| | - P Evalen
- University of the Pacific, Stockton, CA, 95211, USA
| | - Bui D
- University of the Pacific, Stockton, CA, 95211, USA
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6
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Stahlschmidt ZR. Flight capacity drives circadian patterns of metabolic rate and alters resource dynamics. JOURNAL OF EXPERIMENTAL ZOOLOGY PART A: ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:666-674. [PMID: 35438260 PMCID: PMC9324922 DOI: 10.1002/jez.2598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 03/31/2022] [Indexed: 11/29/2022]
Abstract
Animals must acquire, use, and allocate resources, and this balancing act may be influenced by the circadian clock and life‐history strategy. Field (Gryllus) crickets exhibit two distinct life‐history strategies during early adulthood—flight‐capable females invest in flight muscle at a cost to ovary mass, whereas flight‐incapable females instead invest solely into ovaries. In female Gryllus lineaticeps, I investigated the role of life‐history strategy in resource (food) acquisition and allocation, and in circadian patterns of energy use. Flight capacity increased the standard metabolic rate (SMR) due to greater late‐day SMR and flight‐capable crickets exhibited greater circadian rhythmicity in SMR. Flight‐capable crickets also ate less food and were less efficient at converting ingested food into body or ovary mass. Thus, investment into flight capacity reduced fecundity and the amount of resources available for allocation to other life‐history traits. Given the increasing uncertainty of food availability in many global regions, work in Gryllus may clarify the important roles of food and circadian patterns in life‐history evolution in a changing world. In a field cricket, investment into flight capacity (1) increased the circadian rhythmicity of resource use (standard metabolic rate), (2) reduced resource acquisition (food intake), and (3) reduced the efficiency by which ingested food was converted to reproductive tissue.
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7
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Stahlschmidt Z, Vo C. Spatial bet hedging, thermal trade-offs and glyphosate: crickets integrate multivariate information during oviposition. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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Padda SS, Stahlschmidt ZR. Evaluating the effects of water and food limitation on the life history of an insect using a multiple-stressor framework. Oecologia 2022; 198:519-530. [PMID: 35067802 DOI: 10.1007/s00442-022-05115-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 01/11/2022] [Indexed: 11/24/2022]
Abstract
Many environmental stressors naturally covary, and the frequency and duration of stressors such as heat waves and droughts are increasing globally with climate change. Multiple stressors may have additive or non-additive effects on fitness-related traits, such as locomotion, reproduction, and somatic growth. Despite its importance to terrestrial animals, water availability is rarely incorporated into multiple-stressor frameworks. Water limitation often occurs concurrently with food limitation (e.g., droughts can trigger famines), and the acquisition of water and food can be linked because water is necessary for digestion and metabolism. Thus, we investigated the independent and interactive effects of water and food limitation on life-history traits using female crickets (Gryllus firmus), which exhibit a wing dimorphism mediating a life-history trade-off between flight and fecundity. Our results indicate that traits vary in their sensitivities to environmental factors and factor-factor interactions. For example, neither environmental factor affected flight musculature, only water limitation affected survival, and food and water availability non-additively (i.e., interactively) influenced body and ovary mass. Water availability had a larger effect on traits than food availability, affected more traits than food availability, and mediated the effects of food availability. Further, life-history strategy influenced the costs of multiple stressors because females investing in flight capacity exhibited greater reductions in body and ovary mass during stress relative to females lacking flight capacity. Therefore, water is important in the multiple-stressor framework, and understanding the dynamics of covarying environmental factors and life history may be critical in the context of climate change characterized by concurrent environmental stressors.
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Affiliation(s)
- Sugjit S Padda
- University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA.,Department of Ecosystem Science and Management, Pennsylvania State University, State College, PA, 16801, USA
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9
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Stahlschmidt ZR, Chang E. Body condition indices are better surrogates for lean mass and water content than for body fat content in an insect. J Zool (1987) 2021. [DOI: 10.1111/jzo.12909] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | - E. Chang
- University of the Pacific Stockton CA USA
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10
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Husak JF, Fuxjager MJ, Johnson MA, Vitousek MN, Donald JW, Francis CD, Goymann W, Hau M, Kircher BK, Knapp R, Martin LB, Miller ET, Schoenle LA, Williams TD. Life history and environment predict variation in testosterone across vertebrates. Evolution 2021; 75:1003-1010. [PMID: 33755201 DOI: 10.1111/evo.14216] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 02/26/2021] [Accepted: 03/08/2021] [Indexed: 02/06/2023]
Abstract
Endocrine systems act as key intermediaries between organisms and their environments. This interaction leads to high variability in hormone levels, but we know little about the ecological factors that influence this variation within and across major vertebrate groups. We study this topic by assessing how various social and environmental dynamics influence testosterone levels across the entire vertebrate tree of life. Our analyses show that breeding season length and mating system are the strongest predictors of average testosterone concentrations, whereas breeding season length, environmental temperature, and variability in precipitation are the strongest predictors of within-population variation in testosterone. Principles from small-scale comparative studies that stress the importance of mating opportunity and competition on the evolution of species differences in testosterone levels, therefore, likely apply to the entire vertebrate lineage. Meanwhile, climatic factors associated with rainfall and ambient temperature appear to influence variability in plasma testosterone, within a given species. These results, therefore, reveal how unique suites of ecological factors differentially explain scales of variation in circulating testosterone across mammals, birds, reptiles, amphibians, and fishes.
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Affiliation(s)
- Jerry F Husak
- Department of Biology, University of St. Thomas, St. Paul, Minnesota, USA
| | - Matthew J Fuxjager
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, USA
| | | | - Maren N Vitousek
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA.,Cornell Lab of Ornithology, Ithaca, New York, USA
| | | | - Clinton D Francis
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, California, USA
| | | | - Michaela Hau
- Max Planck Institute for Ornithology, Seewiesen, 82319, Germany.,Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| | - Bonnie K Kircher
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | - Rosemary Knapp
- Department of Biology, University of Oklahoma, Norman, Oklahoma, USA
| | - Lynn B Martin
- Department of Global and Planetary Health, University of South Florida, Tampa, Florida, USA
| | | | - Laura A Schoenle
- Department of Global and Planetary Health, University of South Florida, Tampa, Florida, USA.,Office of Undergraduate Biology, Cornell University, Ithaca, New York, USA
| | - Tony D Williams
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
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11
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Zhang L, Cheng L, Chapman JW, Sappington TW, Liu J, Cheng Y, Jiang X. Juvenile hormone regulates the shift from migrants to residents in adult oriental armyworm, Mythimna separata. Sci Rep 2020; 10:11626. [PMID: 32669571 PMCID: PMC7363820 DOI: 10.1038/s41598-020-66973-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 03/26/2020] [Indexed: 11/09/2022] Open
Abstract
In migratory insects, increasing evidence has demonstrated juvenile hormone (JH) is involved in regulating adult reproduction and flight. Our previous study demonstrated that the switch from migrants to residents in Mythimna separata could be induced by adverse environmental conditions during a sensitive period in adulthood (the first day post-emergence), but the role of JH in this switch is not clear. Here, we found a significantly different pattern of JH titers between migrants and residents, with migrants showing a slower release of JH during adulthood than residents. Application of JH analogue (JHA) in the 1-day-old adults, significantly accelerated adult reproduction and suppressed flight capacity. The pre-oviposition period and period of first oviposition of migrants treated with JHA were significantly shorter, while the total lifetime fecundity and mating percentage increased. The flight capacity and dorso-longitudinal muscle size of the migrants were decreased significantly when treated with JHA. The effect of JHA on reproduction and flight capacity indicate that JH titers during the sensitive period (first day post-emergence) regulates the shift from migrants to residents in M. separata.
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Affiliation(s)
- Lei Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Lili Cheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jason W Chapman
- Centre for Ecology and Conservation, and Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom.,Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Thomas W Sappington
- USDA-ARS Corn Insects & Crop Genetics Research Unit, Genetics Laboratory, Iowa State University, Ames, IA, 50011, USA
| | - Juanjuan Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yunxia Cheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xingfu Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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12
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Cell Cycle Progression Determines Wing Morph in the Polyphenic Insect Nilaparvata lugens. iScience 2020; 23:101040. [PMID: 32315833 PMCID: PMC7170998 DOI: 10.1016/j.isci.2020.101040] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/23/2020] [Accepted: 04/01/2020] [Indexed: 12/26/2022] Open
Abstract
Wing polyphenism is a phenomenon in which one genotype can produce two or more distinct wing phenotypes adapted to the particular environment. What remains unknown is how wing pad development is controlled downstream of endocrine signals such as insulin and JNK pathways. We show that genes important in cellular proliferation, cytokinesis, and cell cycle progression are necessary for growth and development of long wings. Wing pad cellular development of the long-winged morph was characterized by a highly structured epithelial layer with microvilli-like structures. Cells of adult short wing pads are largely in the G2/M phase of the cell cycle, whereas those of long wings are largely in G1. Our study is the first to report the comparative developmental and cellular morphology and structure of the wing morphs and to undertake a comprehensive evaluation of the cell cycle genes necessary for wing development of this unique, adaptive life history strategy. Genes important in determining cell numbers are necessary to form long wings Long-winged development was characterized by microvilli-like structures Cells of adult short wing pads are largely in the G2/M phase of the cell cycle Cells of adult long wing pads are largely in the G1 phase of the cell cycle
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13
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Stahlschmidt ZR, Chu I, Koh C. When do looks matter? Effects of mate quality and environmental variability on lifetime reproduction. Behav Ecol Sociobiol 2020. [DOI: 10.1007/s00265-019-2790-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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14
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Stahlschmidt ZR, Jeong N, Johnson D, Meckfessel N. From phenoloxidase to fecundity: food availability does not influence the costs of oxidative challenge in a wing-dimorphic cricket. J Comp Physiol B 2019; 190:17-26. [PMID: 31720761 DOI: 10.1007/s00360-019-01244-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/30/2019] [Accepted: 10/30/2019] [Indexed: 12/11/2022]
Abstract
Stressed animals often struggle to maintain optimal investment into a number of fitness-related traits, which can result in some traits being more adversely affected than others. Variation in stress-related costs may also depend on the environment-costs can be facultative and only occur when resources are limited, or they may be obligate and occur regardless of resource availability. Dynamics of oxidative stress may be important in life-history evolution given their role in a range of biological processes-from reproduction to immunity to locomotion. Thus, we examined how resource (food) availability influences the costs of oxidative challenge to fitness-related traits spanning several levels of biological organization. We manipulated food availability and oxidative status in females of the wing-dimorphic sand field cricket (Gryllus firmus) during early adulthood. We then determined investment into several traits: reproduction (ovary mass), soma (body mass and flight musculature), and immune function (total phenoloxidase activity). Oxidative challenge (paraquat exposure) obligated costs to somatic tissue and a parameter of immune function regardless of food availability, but it did not affect reproduction. We show that the costs of oxidative challenge are trait-specific, but we did not detect a facultative (food-dependent) cost of oxidative challenge to any trait measured. Although the dynamics of oxidative stress are complex, our study is an important step toward a more complete understanding of the roles that resource availability and redox systems play in mediating life histories.
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Affiliation(s)
| | - N Jeong
- University of the Pacific, Stockton, CA, 95211, USA
| | - D Johnson
- University of the Pacific, Stockton, CA, 95211, USA
| | - N Meckfessel
- University of the Pacific, Stockton, CA, 95211, USA
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15
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Wingfield JC. Environmental Endocrinology: Insights into the Diversity of Regulatory Mechanisms in Life Cycles. Integr Comp Biol 2018; 58:790-799. [DOI: 10.1093/icb/icy081] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Affiliation(s)
- John C Wingfield
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616, USA
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16
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Zera AJ, Vellichirammal NN, Brisson JA. Diurnal and developmental differences in gene expression between adult dispersing and flightless morphs of the wing polymorphic cricket, Gryllus firmus: Implications for life-history evolution. JOURNAL OF INSECT PHYSIOLOGY 2018; 107:233-243. [PMID: 29656101 DOI: 10.1016/j.jinsphys.2018.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 03/26/2018] [Accepted: 04/05/2018] [Indexed: 06/08/2023]
Abstract
The functional basis of life history adaptation is a key topic of research in life history evolution. Studies of wing-polymorphism in the cricket Gryllus firmus have played a prominent role in this field. However, prior in-depth investigations of morph specialization have primarily focused on a single hormone, juvenile hormone, and a single aspect of intermediary metabolism, the fatty-acid biosynthetic component of lipid metabolism. Moreover, the role of diurnal variation in life history adaptation in G. firmus has been understudied, as is the case for organisms in general. Here, we identify genes whose expression differs consistently between the morphs independent of time-of-day during early adulthood, as well as genes that exhibit a strong pattern of morph-specific diurnal expression. We find strong, consistent, morph-specific differences in the expression of genes involved in endocrine regulation, carbohydrate and lipid metabolism, and immunity - in particular, in the expression of an insulin-like-peptide precursor gene and genes involved in triglyceride production. We also find that the flight-capable morph exhibited a substantially greater number of genes exhibiting diurnal change in gene expression compared with the flightless morph, correlated with the greater circadian change in the hemolymph juvenile titer in the dispersing morph. In fact, diurnal differences in expression within the dispersing morph at different times of the day were significantly greater in magnitude than differences between dispersing and flightless morphs at the same time-of-day. These results provide important baseline information regarding the potential role of variable gene expression on life history specialization in morphs of G. firmus, and the first information on genetically-variable, diurnal change in gene expression, associated with a key life history polymorphism. These results also suggest the existence of prominent morph-specific circadian differences in gene expression in G. firmus, possibly caused by the morph-specific circadian rhythm in the juvenile hormone titer.
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Affiliation(s)
- Anthony J Zera
- School of Biological Sciences, University of Nebraska-Lincoln, NE 68588, United States.
| | | | - Jennifer A Brisson
- Department of Biology, University of Rochester, Rochester, NY 14627, United States
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Lin X, Lavine LC. Endocrine regulation of a dispersal polymorphism in winged insects: a short review. CURRENT OPINION IN INSECT SCIENCE 2018; 25:20-24. [PMID: 29602358 DOI: 10.1016/j.cois.2017.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/07/2017] [Accepted: 11/10/2017] [Indexed: 06/08/2023]
Abstract
Changes in food availability and crowding are two critical environmental conditions that impact an animal's trajectory toward either reproduction or migration. Many insects facing this challenge have evolved wing polymorpisms that allow them to respond to changing conditions. When conditions favor reproduction, wing polymorphic species produce adults that either have no wings or short, non-functional wings; however, when conditions favor migration, adults with functional wings and robust flight muscles develop. Here we review three recently reported signaling pathways regulating wing polyphenism in wing polymorphic crickets, aphids, and brown planthoppers: juvenile horomone/ecdysone signaling, insulin signaling, and Jun-N-terminal Kinase (JNK) signaling. Understanding how these pathways respond to nutrition, stress and crowding with the appropriate adaptive phenotype is an important step in understanding how life-history trade-offs evolve.
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Affiliation(s)
- Xinda Lin
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China.
| | - Laura Corley Lavine
- Department of Entomology, Washington State University, Pullman, WA 99164-6382, USA
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18
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Conservation Evo-Devo: Preserving Biodiversity by Understanding Its Origins. Trends Ecol Evol 2017; 32:746-759. [DOI: 10.1016/j.tree.2017.07.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 06/27/2017] [Accepted: 07/03/2017] [Indexed: 02/01/2023]
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Zera AJ. Evolutionary Endocrinology of Hormonal Rhythms: Juvenile Hormone Titer Circadian Polymorphism inGryllus firmus. Integr Comp Biol 2016; 56:159-70. [DOI: 10.1093/icb/icw027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Kelstrup HC, Hartfelder K, Nascimento FS, Riddiford LM. The role of juvenile hormone in dominance behavior, reproduction and cuticular pheromone signaling in the caste-flexible epiponine wasp, Synoeca surinama. Front Zool 2014; 11:78. [PMID: 25371699 PMCID: PMC4219083 DOI: 10.1186/s12983-014-0078-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 10/15/2014] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The popular view on insect sociality is that of a harmonious division of labor among two morphologically distinct and functionally non-overlapping castes. But this is a highly derived state and not a prerequisite for a functional society. Rather, caste-flexibility is a central feature in many eusocial wasps, where adult females have the potential to become queens or workers, depending on the social environment. In non-swarming paper wasps (e.g., Polistes), prospective queens fight one another to assert their dominance, with losers becoming workers if they remain on the nest. This aggression is fueled by juvenile hormone (JH) and ecdysteroids, major factors involved in caste differentiation in most eusocial insects. We tested whether these hormones have conserved aggression-promoting functions in Synoeca surinama, a caste-flexible swarm-founding wasp (Epiponini) where reproductive competition is high and aggressive displays are common. RESULTS We observed the behavioral interactions of S. surinama females in field nests before and after we had removed the egg-laying queen(s). We measured the ovarian reproductive status, hemolymph JH and ecdysteroid titers, ovarian ecdysteroid content, and analyzed the cuticular hydrocarbon (CHC) composition of females engaged in competitive interactions in both queenright and queenless contexts. These data, in combination with hormone manipulation experiments, revealed that neither JH nor ecdysteroids are necessary for the expression of dominance behaviors in S. surinama. Instead, we show that JH likely functions as a gonadotropin and directly modifies the cuticular hydrocarbon blend of young workers to match that of a reproductive. Hemolymph ecdysteroids, in contrast, are not different between queens and workers despite great differences in ovarian ecdysteroid content. CONCLUSIONS The endocrine profile of S. surinama shows surprising differences from those of other caste-flexible wasps, although a rise in JH titers in replacement queens is a common theme. Extensive remodeling of hormone functions is also evident in the highly eusocial bees, which has been attributed to the evolution of morphologically defined castes. Our results show that hormones which regulate caste-plasticity can lose these roles even while caste-plasticity is preserved.
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Affiliation(s)
- Hans C Kelstrup
- />Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147 USA
- />Present address: Department of Botany and Zoology, Stellenbosch University, Private Bag XI, Matieland, 7602 South Africa
| | - Klaus Hartfelder
- />Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Universidade de São Paul, Av. Bandeirantes 3900, Ribeirão Preto, 14049-900 SP Brazil
| | - Fabio S Nascimento
- />Departamento de Biologia da Faculdade de Filosofia, Ciȇncias e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, 14040-900 SP Brazil
| | - Lynn M Riddiford
- />Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147 USA
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Hofmann HA, Beery AK, Blumstein DT, Couzin ID, Earley RL, Hayes LD, Hurd PL, Lacey EA, Phelps SM, Solomon NG, Taborsky M, Young LJ, Rubenstein DR. An evolutionary framework for studying mechanisms of social behavior. Trends Ecol Evol 2014; 29:581-9. [DOI: 10.1016/j.tree.2014.07.008] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 07/13/2014] [Accepted: 07/14/2014] [Indexed: 12/31/2022]
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22
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Zeng Y, Zhu DH, Zhao LQ. Critical Flight Time for Switch from Flight to Reproduction in the Wing Dimorphic Cricket Velarifictorus aspersus. Evol Biol 2014. [DOI: 10.1007/s11692-014-9272-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Clark RM, Zera AJ, Behmer ST. Nutritional physiology of life history trade-offs: how food protein-carbohydrate content influences life-history traits in the wing-polymorphic cricket Gryllus firmus. J Exp Biol 2014; 218:298-308. [DOI: 10.1242/jeb.112888] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Abstract
Although life-history trade-offs result from the differential acquisition and allocation of nutritional resources to competing physiological functions, many aspects of this topic remain poorly understood. Wing-polymorphic insects, which possess alternate morphs that trade off allocation to flight capability versus early reproduction, provide a good model system for exploring this topic. In this study we used the wing-polymorphic cricket Gryllus firmus to test how expression of the flight capability vs. reproduction trade-off was modified across a heterogeneous protein-carbohydrate nutritional landscape. Newly molted adult female crickets were given one of 13 diets with different concentrations and ratios of protein and digestible carbohydrate; for each cricket we measured consumption patterns, growth, and allocation to reproduction (ovary mass) vs. flight muscle maintenance (flight muscle mass and somatic lipid stores). Feeding responses in both morphs were influenced more by total macronutrient concentration than protein-carbohydrate ratio, except at high macronutrient concentration, where protein-carbohydrate balance was important. Mass gain tended to be greatest on protein-biased diets for both morphs, but was consistently lower across all diets for long-winged females. When long-winged females were fed high-carbohydrate foods they accumulated greater somatic lipid stores; on high-protein foods they accumulated greater somatic protein stores. Food protein-carbohydrate content also affected short-winged females (selected for early reproductive onset), which showed dramatic increases in ovary size, including ovarian stores of lipids and protein, on protein-biased foods. This is the first study to show how the concentration and ratio of dietary protein and carbohydrate affects consumption and allocation to key physiological features associated with the reproduction-dispersal life-history trade-off.
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Pfister A, Johnson A, Ellers O, Horch HW. Quantification of dendritic and axonal growth after injury to the auditory system of the adult cricket Gryllus bimaculatus. Front Physiol 2013; 3:367. [PMID: 23986706 PMCID: PMC3750946 DOI: 10.3389/fphys.2012.00367] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 08/27/2012] [Indexed: 12/13/2022] Open
Abstract
Dendrite and axon growth and branching during development are regulated by a complex set of intracellular and external signals. However, the cues that maintain or influence adult neuronal morphology are less well understood. Injury and deafferentation tend to have negative effects on adult nervous systems. An interesting example of injury-induced compensatory growth is seen in the cricket, Gryllus bimaculatus. After unilateral loss of an ear in the adult cricket, auditory neurons within the central nervous system (CNS) sprout to compensate for the injury. Specifically, after being deafferented, ascending neurons (AN-1 and AN-2) send dendrites across the midline of the prothoracic ganglion where they receive input from auditory afferents that project through the contralateral auditory nerve (N5). Deafferentation also triggers contralateral N5 axonal growth. In this study, we quantified AN dendritic and N5 axonal growth at 30 h, as well as at 3, 5, 7, 14, and 20 days after deafferentation in adult crickets. Significant differences in the rates of dendritic growth between males and females were noted. In females, dendritic growth rates were non-linear; a rapid burst of dendritic extension in the first few days was followed by a plateau reached at 3 days after deafferentation. In males, however, dendritic growth rates were linear, with dendrites growing steadily over time and reaching lengths, on average, twice as long as in females. On the other hand, rates of N5 axonal growth showed no significant sexual dimorphism and were linear. Within each animal, the growth rates of dendrites and axons were not correlated, indicating that independent factors likely influence dendritic and axonal growth in response to injury in this system. Our findings provide a basis for future study of the cellular features that allow differing dendrite and axon growth patterns as well as sexually dimorphic dendritic growth in response to deafferentation.
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Affiliation(s)
- Alexandra Pfister
- Department of Invertebrate Zoology, American Museum of Natural History New York, NY, USA
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25
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Bloch G, Hazan E, Rafaeli A. Circadian rhythms and endocrine functions in adult insects. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:56-69. [PMID: 23103982 DOI: 10.1016/j.jinsphys.2012.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 10/09/2012] [Accepted: 10/11/2012] [Indexed: 06/01/2023]
Abstract
Many behavioral and physiological processes in adult insects are influenced by both the endocrine and circadian systems, suggesting that these two key physiological systems interact. We reviewed the literature and found that experiments explicitly testing these interactions in adult insects have only been conducted for a few species. There is a shortage of measurements of hormone titers throughout the day under constant conditions even for the juvenile hormones (JHs) and ecdysteroids, the best studied insect hormones. Nevertheless, the available measurements of hormone titers coupled with indirect evidence for circadian modulation of hormone biosynthesis rate, and the expression of genes encoding proteins involved in hormone biosynthesis, binding or degradation are consistent with the hypothesis that the circulating levels of many insect hormones are influenced by the circadian system. Whole genome microarray studies suggest that the modulation of farnesol oxidase levels is important for the circadian regulation of JH biosynthesis in honey bees, mosquitoes, and fruit flies. Several studies have begun to address the functional significance of circadian oscillations in endocrine signaling. The best understood system is the circadian regulation of Pheromone Biosynthesis Activating Neuropeptide (PBAN) titers which is important for the temporal organization of sexual behavior in female moths. The evidence that the circadian and endocrine systems interact has important implications for studies of insect physiology and behavior. Additional studies on diverse species and physiological processes are needed for identifying basic principles underlying the interactions between the circadian and endocrine systems in insects.
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Affiliation(s)
- Guy Bloch
- Department of Ecology, Evolution, and Behavior, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
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26
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Pyenson B, Pollack G. Independent regulation of physiological and behavioral maturation of reproduction in female sand crickets (Gryllus firmus). CAN J ZOOL 2012. [DOI: 10.1139/cjz-2012-0170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the first days of adulthood, ovary size and sexual receptivity increase in female sand crickets ( Gryllus firmus Scudder, 1902). We tested whether these are mechanistically linked by juvenile hormone (JH), which has been implicated in gonadal development and sexual behavior in other insects. Treatment of young females with the JH analog, methoprene, accelerates oocyte maturation and triggers flight-muscle histolysis, but does not affect sexual receptivity. These results are consistent with earlier studies which suggest that physiological and behavioral components of sexual maturation in crickets are separately regulated.
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Affiliation(s)
- B.C. Pyenson
- Department of Biology, McGill University, 1205 Docteur Penfield, Montréal, QC H3A 1B1, Canada
| | - G.S. Pollack
- Department of Biology, McGill University, 1205 Docteur Penfield, Montréal, QC H3A 1B1, Canada
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27
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28
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Laucht S, Dale J, Mutzel A, Kempenaers B. Individual variation in plasma testosterone levels and its relation to badge size in House Sparrows Passer domesticus: it's a night-and-day difference. Gen Comp Endocrinol 2011; 170:501-8. [PMID: 21078322 DOI: 10.1016/j.ygcen.2010.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 11/05/2010] [Accepted: 11/08/2010] [Indexed: 11/15/2022]
Abstract
The steroid hormone testosterone (T) plays a central role in the regulation of reproduction in animals. Although seasonal variation in T levels is well-studied, differences between day and night have only been described in relatively few species, and daily within-individual variation has been largely neglected when evaluating the relationship between T and the expression of sexual ornaments or behavior. We measured plasma T levels during day and night in a captive population of House Sparrows, and analyzed their relationship with an important male ornament--badge size. T levels were on average twice as high at night than during daytime. This was true in all seasons, and in both males and females. Disturbance of the birds at night, but not during the day, led to significantly lower T levels, suggesting a rapid drop after an individual wakes up. The relationship between T levels and badge size depended on the time when T was measured. During the breeding season, badge size was strongly positively correlated with night-time, but not with daytime T levels. This suggests that badge size signals information related to an individual's maximum potential T level such as social dominance. Our study highlights that integrative research on the endocrine control of ornament expression needs to take diel variation in hormone levels into account.
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Affiliation(s)
- Silke Laucht
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Eberhard-Gwinner-Straße, Haus 7/8, D-82319 Seewiesen, Germany.
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29
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Guerra PA. Evaluating the life-history trade-off between dispersal capability and reproduction in wing dimorphic insects: a meta-analysis. Biol Rev Camb Philos Soc 2011; 86:813-35. [PMID: 21199288 DOI: 10.1111/j.1469-185x.2010.00172.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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30
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Tibbetts EA, Izzo A, Huang ZY. Behavioral and physiological factors associated with juvenile hormone in Polistes wasp foundresses. Behav Ecol Sociobiol 2010. [DOI: 10.1007/s00265-010-1126-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Sparkman AM, Byars D, Ford NB, Bronikowski AM. The role of insulin-like growth factor-1 (IGF-1) in growth and reproduction in female brown house snakes (Lamprophis fuliginosus). Gen Comp Endocrinol 2010; 168:408-14. [PMID: 20553722 DOI: 10.1016/j.ygcen.2010.05.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 05/14/2010] [Accepted: 05/24/2010] [Indexed: 10/19/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) is a peptide hormone critically involved in the regulation of key life-history traits such as growth and reproduction. Its structure and function are well-characterized among diverse mammal, fish, and bird species; however, little is known regarding the activities of IGF-1 in non-avian reptiles, particularly snakes and lizards. Nevertheless, several unique characteristics of reptiles, such as high metabolic flexibility and remarkable diversity in life-history strategy, suggest that they are of great interest in the study of endocrinological mechanisms underlying the regulation and evolution of life-history traits. Here we test for a relationship between IGF-1 and individual feeding rate, growth rate and reproductive stage in lab-reared female offspring of wild-caught oviparous house snakes, Lamprophis fuliginosus. We confirm a positive correlation between IGF-1 and both feeding and growth rates in sexually immature snakes, similar to that reported in other taxa. We also show a family effect on IGF-1, suggesting that IGF-1 levels may be heritable in these snakes, and serve as an important target of selection to produce divergent life-history strategies. Furthermore, we provide evidence that suggests that IGF-1 may peak rapidly after first mating, and subsequently decline prior to egg-laying, a phenomenon not previously reported in other taxa. These findings suggest that further comparative study of IGF-1 in snakes may reveal both the extent to which IGF-1 function is conserved across major taxonomic groups, as well as novel and intriguing roles for IGF-1 in the regulation of reproductive activities.
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Affiliation(s)
- A M Sparkman
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA.
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32
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Tibbetts EA, Banan M. Advertised quality, caste and food availability influence the survival cost of juvenile hormone in paper wasps. Proc Biol Sci 2010; 277:3461-7. [PMID: 20534614 DOI: 10.1098/rspb.2010.1003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Life-history trade-offs are often hormonally mediated. Here, we provide a comparative perspective on the endocrine basis of life-history trade-offs by examining the invertebrate hormone juvenile hormone (JH). JH is often associated with benefits, including increased dominance and reproductive success. We tested whether JH reduced survival of Polistes dominulus wasps and whether this survival cost was influenced by factors such as advertised quality, food availability, caste and body size. Overall, JH reduced individual survival. Among fed and unfed queens, JH reduced survival in a dose-dependent manner. Among workers, JH had a stronger effect on survival of fed workers than unfed workers. Unfed workers died quickly and body size was the best predictor of survival. Surprisingly, queens and workers treated with JH survived longer when they had signals advertising high quality than when they had signals advertising low quality. The relationship between advertised quality and ability to withstand high levels of JH suggests that there are differential physiological costs associated with ornament elaboration that could play a role in maintaining signal accuracy over evolutionary time. Overall, the convergence of endocrine-mediated costs across diverse systems suggests that endocrine-mediated trade-offs may be an adaptive way to optimize resource allocation rather than a non-adaptive constraint specific to a particular hormone.
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Affiliation(s)
- Elizabeth A Tibbetts
- Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
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33
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Stay B, Zera AJ. Morph-specific diurnal variation in allatostatin immunostaining in the corpora allata of Gryllus firmus: implications for the regulation of a morph-specific circadian rhythm for JH biosynthetic rate. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:266-270. [PMID: 19913023 DOI: 10.1016/j.jinsphys.2009.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 10/19/2009] [Accepted: 10/26/2009] [Indexed: 05/28/2023]
Abstract
Previous studies have documented a circadian cycle in juvenile hormone (JH) biosynthesis in the long-winged, flight-capable morph, but not in the short-winged flightless morph of the cricket Gryllus firmus. One rapid and reversible inhibitor of in vitro JH biosynthesis by the corpora allata (CA) in crickets is the neuropeptide Phe-Gly-Leu/Ile-amide type of allatostatins (ASTs). To investigate the possible role of allatostatin regulation of the morph-specific circadian cycle of JH production, the quantity of this type of AST in the nerves within the CA was determined by the density of anti-AST-immunostaining in confocal images using the Image J program. The density of immunostaining was inversely related to the rate of JH biosynthesis: Immunostaining in the CA was high and did not differ between morphs early in the photophase when the in vitro rate of JH biosynthesis is low and equivalent in the morphs. However, during the end of the photophase, when the rate of JH biosynthesis rises dramatically in the flight-capable morph, but not in the flightless morph, immunostaining was significantly lower in the flight-capable compared to the flightless morph. These results indicate that morph-specific differences in delivery of AST to the CA and its probable release likely regulate the morph-specific circadian pattern of JH biosynthesis. Also, the negative correlation between AST density and JH production provides evidence for predicting the periods of altered release of these rapid-acting paracine regulators of JH biosynthesis.
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Affiliation(s)
- Barbara Stay
- Department of Biological Sciences, University of Iowa, Iowa City, IA 52242, United States
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Zhao XC, Feng HQ, Wu B, Wu XF, Liu ZF, Wu KM, McNeil JN. Does the onset of sexual maturation terminate the expression of migratory behaviour in moths? A study of the oriental armyworm, Mythimna separata. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:1039-1043. [PMID: 19643107 DOI: 10.1016/j.jinsphys.2009.07.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2009] [Revised: 07/19/2009] [Accepted: 07/20/2009] [Indexed: 05/28/2023]
Abstract
It is generally accepted that in most insects adults are sexually immature when they initiate migration and that migratory behaviour terminates with the onset of sexual maturation. However, a few studies examining the mating status of field collected moths have suggested that sexually mature individuals may continue migrating, but in these cases it was impossible to completely eliminate the possibility that the mated females captured came from local, non-migrant populations. In this study we examined the ovarian development of Mythimna separata females captured using a vertical pointing searchlight trap on Beihuang Island in the Bohai Gulf, China, a site >40km from land. Moths were collected from May to October from 2003 to 2008 in order to test the hypothesis that the onset of sexual maturation resulted in the termination of migratory behaviour. While females at the end of the summer had little ovarian development and were unmated, a significant proportion of those migrating northward in the early summer had developed ovaries and often had at least one spermatophore. Given that theses insects were captured while flying up to 500m above sea level, at a site with no local populations, the findings would not support the hypothesis and suggest that both ovarian development and mating may occur during migration.
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Affiliation(s)
- Xin Cheng Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, PR China
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Husak JF, Irschick DJ. Steroid use and human performance: Lessons for integrative biologists. Integr Comp Biol 2009; 49:354-64. [PMID: 21665826 DOI: 10.1093/icb/icp015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
While recent studies have begun to address how hormones mediate whole-animal performance traits, the field conspicuously lags behind research conducted on humans. Recent studies of human steroid use have revealed that steroid use increases muscle cross-sectional area and mass, largely due to increases in protein synthesis, and muscle fiber hypertrophy attributable to an increased number of satellite cells and myonuclei per unit area. These biochemical and cellular effects on skeletal muscle morphology translate into increased power and work during weight-lifting and enhanced performance in burst, sprinting activities. However, there are no unequivocal data that human steroid use enhances endurance performance or muscle fatigability or recovery. The effects of steroids on human morphology and performance are in general consistent with results found for nonhuman animals, though there are notable discrepancies. However, some of the discrepancies may be due to a paucity of comparative data on how testosterone affects muscle physiology and subsequent performance across different regions of the body and across vertebrate taxa. Therefore, we advocate more research on the basic relationships among hormones, morphology, and performance. Based on results from human studies, we recommend that integrative biologists interested in studying hormone regulation of performance should take into account training, timing of administration, and dosage administered when designing experiments or field studies. We also argue that more information is needed on the long-term effects of hormone manipulation on performance and fitness.
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Affiliation(s)
- Jerry F Husak
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
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Zera AJ, Zhao Z. Morph-associated JH titer diel rhythm in Gryllus firmus: Experimental verification of its circadian basis and cycle characterization in artificially selected lines raised in the field. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:450-458. [PMID: 19100744 DOI: 10.1016/j.jinsphys.2008.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 11/17/2008] [Accepted: 11/21/2008] [Indexed: 05/27/2023]
Abstract
Previous studies demonstrated a high-amplitude, diel cycle for the hemolymph JH titer in the wing-polymorphic cricket, Gryllus firmus. The JH titer rose and fell in the flight-capable morph (long-winged, LW(f)) above and below the relatively temporally invariant JH titer in the flightless (short-winged, SW) morph. The morph-specific JH titer cycle appeared to be primarily driven by a morph-specific diel cycle in the rate of JH biosynthesis. In the present study, cycles of the JH titer and rate of JH biosynthesis in the LW(f) morph persisted in the laboratory under constant darkness with an approximate 24h periodicity. The JH titer cycle also shifted in concert with a shift in the onset of the scotophase, was temperature compensated in constant darkness, and became arrhythmic under constant light. These results provide strong support for the circadian basis of the morph-specific diel rhythm of the JH titer and JH biosynthetic rate. Persistence of the JH titer cycle under constant darkness in multiple LW-selected and SW-selected stocks also provides support for the genetic basis of the morph-associated circadian rhythm. The morph-specific JH titer cycle was observed in these stocks raised in the field, in both males and females, in each of 3 years studied. The onset of the cycle in the LW(f) morph, a few hours before sunset, correlated well with the onset of the cycle, a few hours before lights-off, in the laboratory. The morph-specific JH titer cycle is a general feature of G. firmus, under a variety of environmental conditions, and is not an artifact of specific laboratory conditions or specific genetic stocks. It is a powerful experimental model to investigate the mechanisms underlying endocrine circadian rhythms, their evolution, and their impact on life history evolution.
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Affiliation(s)
- Anthony J Zera
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118, United States.
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Guerra PA, Pollack GS. Flight behaviour attenuates the trade-off between flight capability and reproduction in a wing polymorphic cricket. Biol Lett 2008; 5:229-31. [PMID: 19033134 DOI: 10.1098/rsbl.2008.0570] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Flight-dimorphic insects have been used extensively to study trade-offs between energetically costly traits. Individuals may develop and maintain structures required for flight, or alternatively they may invest in reproduction. Previous experiments have not examined whether flight itself might affect investment into reproduction. As in other Gryllus species, flight-capable individuals of the wing polymorphic cricket, Gryllus texensis, incur an apparent reproductive penalty for being able to fly, expressed as smaller ovaries in females and lower courtship propensity in males, than their flight-incapable counterparts. We find that a short bout of flight eliminates the trade-off. Two days after the flight, the ovaries of flight-capable females were comparable with those of short-winged females. Similarly, flight markedly increased the probability of courtship behaviour. Our results suggest that the impact of the flight-reproduction trade-off described in earlier studies may have been overestimated.
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Affiliation(s)
- Patrick A Guerra
- Department of Biology, McGill University, Montreal, Quebec, Canada H3A 1B1.
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