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Chapman A, McAfee A, Tarpy DR, Fine J, Rempel Z, Peters K, Currie R, Foster LJ. Common viral infections inhibit egg laying in honey bee queens and are linked to premature supersedure. Sci Rep 2024; 14:17285. [PMID: 39068210 PMCID: PMC11283550 DOI: 10.1038/s41598-024-66286-5] [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: 04/29/2024] [Accepted: 07/01/2024] [Indexed: 07/30/2024] Open
Abstract
With their long lives and extreme reproductive output, social insect queens have escaped the classic trade-off between fecundity and lifespan, but evidence for a trade-off between fecundity and immunity has been inconclusive. This is in part because pathogenic effects are seldom decoupled from effects of immune induction. We conducted parallel, blind virus infection experiments in the laboratory and in the field to interrogate the idea of a reproductive immunity trade-off in honey bee (Apis mellifera) queens and to better understand how these ubiquitous stressors affect honey bee queen health. We found that queens injected with infectious virus had smaller ovaries and were less likely to recommence egg-laying than controls, while queens injected with UV-inactivated virus displayed an intermediate phenotype. In the field, heavily infected queens had smaller ovaries and infection was a meaningful predictor of whether supersedure cells were observed in the colony. Immune responses in queens receiving live virus were similar to queens receiving inactivated virus, and several of the same immune proteins were negatively associated with ovary mass in the field. This work supports the hypothesized relationship between virus infection and symptoms associated with queen failure and suggests that a reproductive-immunity trade-off is partially, but not wholly responsible for these effects.
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Affiliation(s)
- Abigail Chapman
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, Canada.
| | - Alison McAfee
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, USA
| | - David R Tarpy
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, USA
| | - Julia Fine
- Invasive Species and Pollinator Health Research Unit, USDA-ARS, Davis, CA, USA
| | - Zoe Rempel
- Department of Entomology, University of Manitoba, Winnipeg, MB, Canada
| | - Kira Peters
- Department of Entomology, University of Manitoba, Winnipeg, MB, Canada
| | - Rob Currie
- Department of Entomology, University of Manitoba, Winnipeg, MB, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
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2
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Carmona-Aldana F, Yong LW, Reinberg D, Desplan C. Phenomenon of reproductive plasticity in ants. CURRENT OPINION IN INSECT SCIENCE 2024; 63:101197. [PMID: 38583769 PMCID: PMC11139587 DOI: 10.1016/j.cois.2024.101197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 03/26/2024] [Accepted: 03/31/2024] [Indexed: 04/09/2024]
Abstract
Ant colonies are organized in castes with distinct behaviors that together allow the colony to strive. Reproduction relies on one or a few queens that stay in the nest producing eggs, while females of the worker caste do not reproduce and instead engage in colony maintenance and brood caretaking. Yet, in spite of this clear separation of functions, workers can become reproductive under defined circumstances. Here, we review the context in which workers become reproductive, exhibiting asexual or sexual reproduction depending on the species. Remarkably, the activation of reproduction in these workers can be quite stable, with changes that include behavior and a dramatic extension of lifespan. We compare these changes between species that do or do not have a queen caste. We discuss how the mechanisms underlying reproductive plasticity include changes in hormonal functions and in epigenetic configurations. Further studies are warranted to elucidate not only how reproductive functions have been gradually restricted to the queen caste during evolution but also how reproductive plasticity remains possible in workers of some species.
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Affiliation(s)
| | - Luok Wen Yong
- Department of Biology, New York University, NY 10003, USA
| | - Danny Reinberg
- Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Coral Gables, FL 33124, USA.
| | - Claude Desplan
- Department of Biology, New York University, NY 10003, USA; Center for Genomics and Systems Biology, New York University, Abu Dhabi 51133, United Arab Emirates.
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3
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Lanz-Mendoza H, Gálvez D, Contreras-Garduño J. The plasticity of immune memory in invertebrates. J Exp Biol 2024; 227:jeb246158. [PMID: 38449328 DOI: 10.1242/jeb.246158] [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] [Indexed: 03/08/2024]
Abstract
Whether specific immune protection after initial pathogen exposure (immune memory) occurs in invertebrates has long been uncertain. The absence of antibodies, B-cells and T-cells, and the short lifespans of invertebrates led to the hypothesis that immune memory does not occur in these organisms. However, research in the past two decades has supported the existence of immune memory in several invertebrate groups, including Ctenophora, Cnidaria, Nematoda, Mollusca and Arthropoda. Interestingly, some studies have demonstrated immune memory that is specific to the parasite strain. Nonetheless, other work does not provide support for immune memory in invertebrates or offers only partial support. Moreover, the expected biphasic immune response, a characteristic of adaptive immune memory in vertebrates, varies within and between invertebrate species. This variation may be attributed to the influence of biotic or abiotic factors, particularly parasites, on the outcome of immune memory. Despite its critical importance for survival, the role of phenotypic plasticity in immune memory has not been systematically examined in the past two decades. Additionally, the features of immune responses occurring in diverse environments have yet to be fully characterized.
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Affiliation(s)
- Humberto Lanz-Mendoza
- Centro de Investigaciones sobre Enfermedades Infecciosas, INSP, 62100 Cuernavaca, Morelos, Mexico
| | - Dumas Gálvez
- Coiba Scientific Station, City of Knowledge, Calle Gustavo Lara, Boulevard 145B, Clayton 0843-01853, Panama
- Programa Centroamericano de Maestría en Entomología, Universidad de Panamá, Estafeta universitaria, Avenida Simón Bolívar, 0824, Panama
- Sistema Nacional de Investigación, Edificio 205, Ciudad del Saber, 0816-02852, Panama
| | - Jorge Contreras-Garduño
- Escuela Nacional de Estudios Superiores, Unidad Morelia, UNAM, 58190 Morelia, Mexico
- Institute for Evolution and Biodiversity, University of Münster, 48149 Münster, Germany
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McAfee A, Chapman A, Bao G, Tarpy DR, Foster LJ. Investigating trade-offs between ovary activation and immune protein expression in bumble bee ( Bombus impatiens) workers and queens. Proc Biol Sci 2024; 291:20232463. [PMID: 38264776 PMCID: PMC10806398 DOI: 10.1098/rspb.2023.2463] [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: 11/03/2023] [Accepted: 12/20/2023] [Indexed: 01/25/2024] Open
Abstract
Evidence for a trade-off between reproduction and immunity has manifested in many animal species, including social insects. However, investigations in social insect queens present a conundrum: new gynes of many social hymenopterans, such as bumble bees and ants, must first mate, then transition from being solitary to social as they establish their nests, thus experiencing confounding shifts in environmental conditions. Worker bumble bees offer an opportunity to investigate patterns of immune protein expression associated with ovary activation while minimizing extraneous environmental factors and genetic differences. Here, we use proteomics to interrogate the patterns of immune protein expression of female bumble bees (Bombus impatiens) by (i) sampling queens at different stages of their life cycle, then (ii) by sampling workers with different degrees of ovary activation. Patterns of immune protein expression in the haemolymph of queens are consistent with a reproduction-immunity trade-off, but equivalent samples from workers are not. This brings into question whether queen bumble bees really experience a reproduction-immunity trade-off, or if patterns of immune protein expression may actually be due to the selective pressure of the different environmental conditions they are exposed to during their life cycle.
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Affiliation(s)
- Alison McAfee
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada V6T1Z4
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695-7617, USA
| | - Abigail Chapman
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada V6T1Z4
| | - Grace Bao
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada V6T1Z4
| | - David R. Tarpy
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695-7617, USA
| | - Leonard J. Foster
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada V6T1Z4
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Ren Q, Ma L, Zhang X, Chen L, Mao Z, Li D, Zhang L, Jiang X. Effect of Juvenile Hormone on Worker Behavioral Transition in the Red Imported Fire Ant, Solenopsis invicta (Hymenoptera: Formicidae). INSECTS 2023; 14:934. [PMID: 38132607 PMCID: PMC10743645 DOI: 10.3390/insects14120934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/03/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023]
Abstract
The division of labor among workers is a defining characteristic of social insects and plays a pivotal role in enhancing the competitive advantage of their colony. Juvenile hormone (JH) has long been hypothesized to be the essential driver in regulating the division of labor due to its ability to accelerate behavioral transitions in social insects, such as honeybees. The regulation of behavioral transitions by JH in the red imported fire ant (RIFA), Solenopsis invicta, a typical social pest, is unclear. Through video capture and analysis, we investigated the effects of the juvenile hormone analogue (JHA) methoprene on brood care, phototaxis behavior, and threat responsiveness of RIFA nurse workers. Our results showed that the JHA application significantly reduced the time and frequency of brood care behavior by nurse workers while increasing their walking distance and activity time in the light area. Additionally, the application of JHA made ants become excited, indicating a significant improvement in their activity level (movement distance, time, and speed). Furthermore, it was observed that the application of JHA did not affect the threat responsiveness of nurse workers towards stimuli (nestmates or non-nestmates). Our study demonstrates that the application of JHA reduced brood care behavior and enhanced phototaxis in nurse workers, which may reveal the role of JH in facilitating behavioral transitions in RIFA from intranidal tasks to extranidal activity. This study provides an experimental basis for further elucidating the mechanism underlying the division of labor in social insects.
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Affiliation(s)
- Qilin Ren
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China; (Q.R.); (L.M.); (X.Z.)
| | - Lin Ma
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China; (Q.R.); (L.M.); (X.Z.)
| | - Xiaolong Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China; (Q.R.); (L.M.); (X.Z.)
| | - Libiao Chen
- Guangxi Green City Pest Control Technology Co., Ltd., Nanning 530007, China;
| | - Zhigang Mao
- Guangxi Beitou Urban Environmental Governance Group Co., Ltd., Nanning 530000, China; (Z.M.); (D.L.)
| | - Dongdong Li
- Guangxi Beitou Urban Environmental Governance Group Co., Ltd., Nanning 530000, China; (Z.M.); (D.L.)
| | - Lei Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China; (Q.R.); (L.M.); (X.Z.)
| | - Xingfu Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China; (Q.R.); (L.M.); (X.Z.)
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Wynants E, Van Dun C, Lenaerts N, Princen SA, Tuyttens E, Shpigler HY, Wenseleers T, Van Oystaeyen A. Uncovering the role of juvenile hormone in ovary development and egg laying in bumble bees. JOURNAL OF INSECT PHYSIOLOGY 2023; 150:104557. [PMID: 37625783 DOI: 10.1016/j.jinsphys.2023.104557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023]
Abstract
Juvenile hormone (JH) regulates developmental and physiological processes in insects. In bumble bees, the hormone acts as a gonadotropin that mediates ovary development, but the exact physiological pathways involved in ovary activation and subsequent egg laying are poorly understood. In this study, we examine how queen hibernation state, caste, and species impact the gonadotropic effect of JH in bumble bee queens through methoprene (JH analogue) application. We extend previous research by assessing queen egg laying and colony initiation, alongside ovary development. Furthermore, we compared sensitivity of workers of both species to the juvenile hormone's gonadotropic effect. In both bumble bee species, the ovaries of hibernated queens were developed five to six days after breaking diapause, regardless of methoprene treatment. By contrast, methoprene did have a stimulatory effect on ovary development in non-hibernated queens. The dose needed to obtain this effect was higher in B. impatiens. Methoprene did not have gonadotropic effects in callow workers of both species. These results indicate that the physiological effect of exogenous methoprene application varies according to species, caste and hibernation status. Interestingly, despite gonadotropic effects in non-hibernated queens, oviposition was not accelerated by JH. This suggests that JH alone is insufficient to induce egg laying and that an additional stimulus, which is naturally present in hibernated queens, is required. Consequently, our findings indicate that other physiological processes, beyond a rise in JH alone, are required for oviposition and colony initiation.
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Affiliation(s)
- Enya Wynants
- Biobest Group NV, Research and Development, 2260 Westerlo, Belgium
| | - Cédric Van Dun
- Laboratory of Socio-ecology and Social Evolution, University of Leuven, 3000 Leuven, Belgium
| | - Nancy Lenaerts
- Biobest Group NV, Research and Development, 2260 Westerlo, Belgium
| | - Sarah A Princen
- Biobest Group NV, Research and Development, 2260 Westerlo, Belgium
| | - Ella Tuyttens
- Biobest Group NV, Research and Development, 2260 Westerlo, Belgium
| | - Hagai Y Shpigler
- Department of Entomology, Agricultural Research Organization, The Volcani Institute, Rishon LeZion, Israel
| | - Tom Wenseleers
- Laboratory of Socio-ecology and Social Evolution, University of Leuven, 3000 Leuven, Belgium
| | - Annette Van Oystaeyen
- Biobest Group NV, Research and Development, 2260 Westerlo, Belgium; Laboratory of Socio-ecology and Social Evolution, University of Leuven, 3000 Leuven, Belgium.
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7
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Amaro-Sánchez T, Ruiz-Guzmán G, Hernández-Martínez S, Krams I, Rantala MJ, Contreras-Garduño J. Effect of juvenile hormone on phenoloxidase and hemocyte number: The role of age, sex, and immune challenge. Comp Biochem Physiol B Biochem Mol Biol 2023; 265:110827. [PMID: 36610635 DOI: 10.1016/j.cbpb.2023.110827] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 01/02/2023] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Hormones are key factors in determining the response of organisms to their environment. For example, the juvenile hormone (JH) coordinates the insects' development, reproduction, and survival. However, it is still unclear how the impact of juvenile hormone on insect immunity varies depending on the sex and reproductive state of the individual, as well as the type of the immune challenge (i.e., Gram-positive or Gram-negative bacteria). We used Tenebrio molitor and methoprene, a JH analog (JHa) to explore these relationships. We tested the effect of methoprene on phenoloxidase activity (PO), an important component of humoral immunity in insects, and hemocyte number. Lyophilized Gram-positive Staphylococcus aureus or Gram-negative Escherichia coli were injected for the immune challenge. The results suggest that JH did not affect the proPO, PO activity, or hemocyte number of larvae. JH and immune challenge affected the immune response and consequently, affected adult developmental stage and sex. We propose that the influence of JH on the immune response depends on age, sex, the immune response parameter, and the immune challenge, which may explain the contrasting results about the role of JH in the insect immune response.
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Affiliation(s)
- Tania Amaro-Sánchez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Campus Guanajuato, Noria Alta s/n, Colonia Noria Alta, 36050 Guanajuato, Mexico
| | - Gloria Ruiz-Guzmán
- Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No.8701, Col. Ex-Hacienda San José de la Huerta, 58190 Morelia, Michoacán, Mexico
| | - Salvador Hernández-Martínez
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, 62300 Cuernavaca, Morelos, Mexico
| | - Indrikis Krams
- Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia; Department of Biotechnology, Daugavpils University, Daugavpils 5401, Latvia; Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Riga 1004, Latvia
| | - Markus J Rantala
- Department of Biology & Turku Brain and Mind Center, University of Turku, Turku, Finland
| | - Jorge Contreras-Garduño
- Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No.8701, Col. Ex-Hacienda San José de la Huerta, 58190 Morelia, Michoacán, Mexico.
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8
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Role of juvenile hormone in oogenesis, chemical profile, and behavior of the wasp Mischocyttarus consimilis (Vespidae: Polistinae). CHEMOECOLOGY 2022. [DOI: 10.1007/s00049-022-00378-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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9
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da Silva RC, do Nascimento FS, Wenseleers T, Oi CA. Juvenile hormone modulates hydrocarbon expression and reproduction in the german wasp Vespula germanica. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1024580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Juvenile hormone (JH) affects multiple physiological traits in insects. In social insects, besides development, JH has been demonstrated to influence caste determination and the production of chemical compounds. In social wasps, JH triggers behavioral maturation, gonadotropic effects, and hydrocarbon modulation. Here, we investigated whether JH displays the same function in fertility and fertility cue production in females of the German wasp Vespula germanica, previously shown in the related species Vespula vulgaris. By experimentally treating workers with JH-analog, an anti-JH, and acetone solvent control, we tested whether JH modulates the cuticular chemical expression (CHCs), the Dufour’s gland chemical composition, and hence the compounds found over the egg’s surface. Additionally, we explored whether JH has a gonadotropic effect on workers. Workers treated with the JH-analog acquired a chemical profile that was intermediate between the queen and other treated workers. Interestingly, the same pattern was also seen in the Dufour’s glands and eggs, although more subtle. Furthermore, workers treated with the JH-analog were more fertile when compared to the controls, supporting the fact that JH acts as a gonadotropic hormone. Our results indicate a similar function of JH in societies of related wasp species V. germanica and V. vulgaris.
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10
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Oi CA, da Silva RC, Stevens I, Ferreira HM, Nascimento FS, Wenseleers T. Hormonal modulation of reproduction and fertility signaling in polistine wasps. Curr Zool 2021; 67:519-530. [PMID: 34616950 PMCID: PMC8489163 DOI: 10.1093/cz/zoab026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 03/10/2021] [Indexed: 12/15/2022] Open
Abstract
In social insects, it has been suggested that reproduction and the production of particular fertility-linked cuticular hydrocarbons (CHC) may be under shared juvenile hormone (JH) control, and this could have been key in predisposing such cues to later evolve into full-fledged queen pheromone signals. However, to date, only few studies have experimentally tested this "hormonal pleiotropy" hypothesis. Here, we formally test this hypothesis using data from four species of Polistine wasps, Polistes dominula, Polistes satan, Mischocyttarus metathoracicus, and Mischocyttarus cassununga, and experimental treatments with JH using the JH analogue methoprene and the anti-JH precocene. In line with reproduction being under JH control, our results show that across these four species, precocene significantly decreased ovary development when compared with both the acetone solvent-only control and the methoprene treatment. Consistent with the hormonal pleiotropy hypothesis, these effects on reproduction were further matched by subtle shifts in the CHC profiles, with univariate analyses showing that in P. dominula and P. satan the abundance of particular linear alkanes and mono-methylated alkanes were affected by ovary development and our hormonal treatments. The results indicate that in primitively eusocial wasps, and particularly in Polistes, reproduction and the production of some CHC cues are under joint JH control. We suggest that pleiotropic links between reproduction and the production of such hydrocarbon cues have been key enablers for the origin of true fertility and queen signals in more derived, advanced eusocial insects.
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Affiliation(s)
- Cintia Akemi Oi
- Laboratory of Socioecology and Social Evolution, KU Leuven, Leuven 3000, Belgium
| | - Rafael Carvalho da Silva
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Universidade de São Paulo-USP, Ribeirão Preto, SP 14040-901, Brazil
| | - Ian Stevens
- Laboratory of Socioecology and Social Evolution, KU Leuven, Leuven 3000, Belgium
| | | | - Fabio Santos Nascimento
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Universidade de São Paulo-USP, Ribeirão Preto, SP 14040-901, Brazil
| | - Tom Wenseleers
- Laboratory of Socioecology and Social Evolution, KU Leuven, Leuven 3000, Belgium
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Opachaloemphan C, Mancini G, Konstantinides N, Parikh A, Mlejnek J, Yan H, Reinberg D, Desplan C. Early behavioral and molecular events leading to caste switching in the ant Harpegnathos. Genes Dev 2021; 35:410-424. [PMID: 33602869 PMCID: PMC7919410 DOI: 10.1101/gad.343699.120] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/15/2021] [Indexed: 12/14/2022]
Abstract
Ant societies show a division of labor in which a queen is in charge of reproduction while nonreproductive workers maintain the colony. In Harpegnathos saltator, workers retain reproductive ability, inhibited by the queen pheromones. Following the queen loss, the colony undergoes social unrest with an antennal dueling tournament. Most workers quickly abandon the tournament while a few workers continue the dueling for months and become gamergates (pseudoqueens). However, the temporal dynamics of the social behavior and molecular mechanisms underlining the caste transition and social dominance remain unclear. By tracking behaviors, we show that the gamergate fate is accurately determined 3 d after initiation of the tournament. To identify genetic factors responsible for this commitment, we compared transcriptomes of different tissues between dueling and nondueling workers. We found that juvenile hormone is globally repressed, whereas ecdysone biosynthesis in the ovary is increased in gamergates. We show that molecular changes in the brain serve as earliest caste predictors compared with other tissues. Thus, behavioral and molecular data indicate that despite the prolonged social upheaval, the gamergate fate is rapidly established, suggesting a robust re-establishment of social structure.
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Affiliation(s)
- Comzit Opachaloemphan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
| | - Giacomo Mancini
- Department of Biology, New York University, New York, New York 10003, USA
| | | | - Apurva Parikh
- Department of Biology, New York University, New York, New York 10003, USA
| | - Jakub Mlejnek
- Department of Biology, New York University, New York, New York 10003, USA
| | - Hua Yan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, New York 10016, USA
| | - Danny Reinberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, New York 10016, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, New York 10003, USA
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12
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Aceves-Aparicio E, Pérez-Staples D, Arredondo J, Corona-Morales A, Morales-Mávil J, Díaz-Fleischer F. Combined Effects of Methoprene and Metformin on Reproduction, Longevity, and Stress Resistance in Anastrepha ludens (Diptera: Tephritidae): Implications for the Sterile Insect Technique. JOURNAL OF ECONOMIC ENTOMOLOGY 2021; 114:142-151. [PMID: 33558906 DOI: 10.1093/jee/toaa295] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Indexed: 06/12/2023]
Abstract
Survival and mating success are traits of quality in mass-reared sterile males. Thus, studying the trade-offs between these traits may help to improve process in the sterile insect technique (SIT). Here, we tested the hypothesis that modifying individual metabolism, especially of energetic reserves, may reduce the negative impact of an early reproduction on the survival of Anastrepha ludens flies. Appling metformin (a drug used to treat type II diabetes) that improves insects' survival, through dietary restriction mimicry, and methoprene (a juvenile hormone analogue) that accelerates the age to reproduction in insects, we explore the dynamic of this trade-off. We fed A. ludens flies with metformin, methoprene, or a mixture of metformin-methoprene for five consecutive days. We determined the effect of these treatments on the fecundity and fertility (number of eggs and percentage of hatching) of females, on sexual maturation and mating success of males, and on the survival of both sexes. The results showed that the acceleration in sexual maturation by the action of methoprene significantly reduced survival in both sexes of two different fly strains. However, adding metformin to the diet buffered this negative effect, without reducing the mating propensity compared with the males treated only with methoprene. The response to metformin was sex-specific since females responded to high doses of the substance, whereas males responded better to low doses. These results suggest that trade-offs between survival and reproduction do not necessarily depend on energy reserves but they are intrinsically related to metabolic regulation and hormonal control.
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Affiliation(s)
| | | | - José Arredondo
- MOSCAFRUT, Subdirección de Desarrollo de Métodos, SADER-IICA, Metapa de Domínguez, Chiapas, México
| | - Aleph Corona-Morales
- Facultad de Nutrición, Universidad Veracruzana, Médicos, U. H del Bosque, CP, Xalapa, Veracruz, México
| | - Jorge Morales-Mávil
- Instituto de Neuroetología, Universidad Veracruzana, Av. Dr. Luis Castelazo, Industrial de las ánimas, CP, Xalapa, Veracruz, México
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13
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Tibbetts EA, Laub EC, Mathiron AGE, Goubault M. The challenge hypothesis in insects. Horm Behav 2020; 123:104533. [PMID: 31185222 DOI: 10.1016/j.yhbeh.2019.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/09/2019] [Accepted: 05/16/2019] [Indexed: 11/23/2022]
Abstract
The 'challenge hypothesis' provides a predictive framework for how the social environment influences within-species variation in hormone titers. High testosterone levels are beneficial during reproduction and competition, but they also impose costs because they may suppress traits like parental care and immunity. As a result, the challenge hypothesis predicts that individuals will change their testosterone levels to match the current social environment. Although the vast majority of work on the challenge hypothesis has focused on androgens in vertebrates, there is growing evidence that insect hormones, especially juvenile hormone (JH), may respond to social stimuli in ways that parallel androgens in vertebrates. Many insects rapidly upregulate JH titers during social competition with rivals. Some insects also modulate JH titers based on contest outcomes, with winners upregulating JH and losers downregulating JH. This review will integrate work on social modulation of hormone titers in vertebrates and insects. First, we provide background on insect hormones and describe the functional parallels between androgens and JH. Second, we review evidence that insects rapidly change JH titers in response to social competition. Finally, we highlight opportunities for future work on social modulation of hormones in insects. Overall, the challenge hypothesis provides a useful conceptual framework for hypothesis-driven research in insect endocrinology. Comparing vertebrates and insects provides insight into how selection has shaped patterns of hormone responsiveness as well as the generality of hypotheses originally developed for vertebrates.
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Affiliation(s)
- Elizabeth A Tibbetts
- Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Emily C Laub
- Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Anthony G E Mathiron
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261 CNRS, Université de Tours, Parc Grandmont, 37200 Tours, France
| | - Marlene Goubault
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261 CNRS, Université de Tours, Parc Grandmont, 37200 Tours, France
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14
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Walton A, Tumulty JP, Toth AL, Sheehan MJ. Hormonal modulation of reproduction in Polistes fuscatus social wasps: Dual functions in both ovary development and sexual receptivity. JOURNAL OF INSECT PHYSIOLOGY 2020; 120:103972. [PMID: 31705844 PMCID: PMC7558460 DOI: 10.1016/j.jinsphys.2019.103972] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 11/02/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
Hormones are often major regulators of complex behaviors, such as mating and reproduction. In insects, juvenile hormone (JH) is integral to many components of reproductive physiology and behavior, but its role in female sexual receptivity is not well understood. To investigate the influence of JH on receptivity, we utilized the social wasp Polistes fuscatus. In Polistes, mating behavior is temporally separated from other components of reproduction, which allows for examination of the physiology and behavior of mating, disentangled from fertilization and egg-laying. We reared virgin gynes (reproductive females) in the lab and divided them into four groups, in which gynes received multiple topical treatments of either 20 μg, 10 μg, 5 μg, or 0 μg of the JH analog methoprene. Gynes were then placed in petri dishes with 2 unrelated males and we recorded attempted and successful mating. Additionally, we measured gyne ovarian development and survival in each group. We found that methoprene increased both sexual receptivity and ovarian development, but was associated with a decrease in long-term survival. Receptivity increased linearly as methoprene treatment increased, but the effect of methoprene on ovarian development was independent of dose. These results demonstrate the importance of JH in sexual receptivity and mating behavior. We argue that the relatively understudied Polistes gyne has potential as a model for mating and reproduction, and for the internal and external regulation of this complex behavior.
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Affiliation(s)
- Alexander Walton
- Department of Neurobiology and Behavior, Cornell University, United States; Department of Ecology, Evolution, and Organismal Biology, Iowa State University, United States.
| | - James P Tumulty
- Department of Neurobiology and Behavior, Cornell University, United States
| | - Amy L Toth
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, United States
| | - Michael J Sheehan
- Department of Neurobiology and Behavior, Cornell University, United States
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15
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Elgendy AM, Tufail M, Mohamed AA, Takeda M. A putative direct repeat element plays a dual role in the induction and repression of insect vitellogenin-1 gene expression. Comp Biochem Physiol B Biochem Mol Biol 2019; 234:1-8. [PMID: 31022468 DOI: 10.1016/j.cbpb.2019.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/06/2019] [Accepted: 04/15/2019] [Indexed: 11/15/2022]
Abstract
Juvenile hormones (JH) regulate wide-ranging physiological and developmental processes in insects. However, molecular mechanisms underlying JH signaling remain to be determined. Vitellogenin (Vg) is primarily an egg-yolk protein, but recently proposed to serve many functions in insects. In the female American cockroach (Periplaneta americana), vitellogenin (Vg) genes are activated by JH III and suppressed by 20-hydroxyecdysone (20E) via cis-regulatory elements in a dose-dependent manner. In the present study, the upstream promoter region (935 bp) of Vg1 was cloned to elucidate the action of these hormones. A luciferase reporter assay identified an 81 bp region in the promoter region of Vg1 (-120 to -39 bp) that we found to be critical for JH III activation and 20E suppression. This 81 bp region contains a direct repeat separated by a 2-nucleotide spacer-designated Vg1HRE- that is similar to the Drosophila ecdysone response element direct repeat 4. Moreover, nuclear proteins isolated from nymphs, males, females, and Sf9 cells successfully bound to Vg1HRE, while binding was outcompeted by a 100-fold excess of cold probe or dephosphorylated nuclear protein extracts. In addition, binding was outcompeted by other ecdysone and JH response elements with similar half-site sequences (direct repeats) but to varying extents. Ultimately, we postulate that JH III indirectly activates Vg expression by interfering with or inhibiting the phosphorylation of nuclear proteins bound to Vg1HRE. Involvement of JH III in both induction of Vg1 and control of nuclear proteins binding to Vg1HRE suggest the latter to play an important role in JH signaling.
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Affiliation(s)
- Azza M Elgendy
- Department of Entomology, Faculty of Science, Cairo University, PO Box 12613, Giza, Egypt.
| | - Muhammad Tufail
- Economic Entomology Research Unit, Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia; Organization of Advanced Science and Technology, Kobe University, Kobe 657-8501, Japan.
| | - Amr A Mohamed
- Department of Entomology, Faculty of Science, Cairo University, PO Box 12613, Giza, Egypt.
| | - Makio Takeda
- Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Hyogo, Japan.
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16
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Norman VC, Pamminger T, Nascimento F, Hughes WOH. The role of juvenile hormone in regulating reproductive physiology and dominance in Dinoponera quadriceps ants. PeerJ 2019; 7:e6512. [PMID: 30842903 PMCID: PMC6398374 DOI: 10.7717/peerj.6512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 01/24/2019] [Indexed: 12/18/2022] Open
Abstract
Unequal reproductive output among members of the same sex (reproductive skew) is a common phenomenon in a wide range of communally breeding animals. In such species, reproductive dominance is often acquired during antagonistic interactions between group members that establish a reproductive hierarchy in which only a few individuals reproduce. Rank-specific syndromes of behavioural and physiological traits characterize such hierarchies, but how antagonistic behavioural interactions translate into stable rank-specific syndromes remains poorly understood. The pleiotropic nature of hormones makes them prime candidates for generating such syndromes as they physiologically integrate environmental (social) information, and often affect reproduction and behaviour simultaneously. Juvenile hormone (JH) is one of several hormones that occupy such a central regulatory role in insects and has been suggested to regulate reproductive hierarchies in a wide range of social insects including ants. Here we use experimental manipulation to investigate the effect of JH levels on reproductive physiology and social dominance in high-ranked workers of the eusocial ant Dinoponera quadriceps, a species that has secondarily reverted to queenless, simple societies. We show that JH regulated reproductive physiology, with ants in which JH levels were experimentally elevated having more regressed ovaries. In contrast, we found no evidence of JH levels affecting dominance in social interactions. This could indicate that JH and ovary development are decoupled from dominance in this species, however only high-ranked workers were investigated. The results therefore confirm that the regulatory role of JH in reproductive physiology in this ant species is in keeping with its highly eusocial ancestors rather than its secondary reversion to simple societies, but more investigation is needed to disentangle the relationships between hormones, behaviour and hierarchies.
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Affiliation(s)
- Victoria C Norman
- School of Biology, University of Leeds, Leeds, United Kingdom.,School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Tobias Pamminger
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Fabio Nascimento
- Departamento de Biologia, Universidade de São Paulo, Ribeirão Preto, Brazil
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17
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Kohlmeier P, Alleman AR, Libbrecht R, Foitzik S, Feldmeyer B. Gene expression is more strongly associated with behavioural specialization than with age or fertility in ant workers. Mol Ecol 2019; 28:658-670. [PMID: 30525254 DOI: 10.1111/mec.14971] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 11/09/2018] [Accepted: 11/15/2018] [Indexed: 12/19/2022]
Abstract
The ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and more corpulent. Here, we experimentally disentangle behavioural specialization from age and fertility in Temnothorax longispinosus ant workers and analyse how these parameters are linked to whole-body gene expression. A total of 3,644 genes were associated with behavioural specialization which is ten times more than associated with age and 50 times more than associated with fertility. Brood carers were characterized by an upregulation of three Vitellogenin (Vg) genes, one of which, Vg-like A, was the most differentially expressed gene that was recently shown experimentally to control the switch from brood to worker care. The expression of Conventional Vg was unlinked to behavioural specialization, age or fertility, which contrasts to studies on bees and some ants. Diversity in Vg/Vg-like copy number and expression bias across ants supports subfunctionalization of Vg genes and indicates that some regulatory mechanisms of division of labour diverged in different ant lineages. Simulations revealed that our experimental dissociation of co-varying factors reduced transcriptomic noise, suggesting that confounding factors could potentially explain inconsistencies across transcriptomic studies of behavioural specialization in ants. Thus, our study reveals that worker gene expression is mainly linked to the worker's function for the colony and provides novel insights into the evolution of sociality in ants.
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Affiliation(s)
- Philip Kohlmeier
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Austin R Alleman
- 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
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
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18
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Kohlmeier P, Feldmeyer B, Foitzik S. Vitellogenin-like A-associated shifts in social cue responsiveness regulate behavioral task specialization in an ant. PLoS Biol 2018; 16:e2005747. [PMID: 29874231 PMCID: PMC5991380 DOI: 10.1371/journal.pbio.2005747] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/03/2018] [Indexed: 11/22/2022] Open
Abstract
Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor, with workers specializing in brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here, we show that a Vitellogenin (Vg) ortholog identified in an RNAseq study on the ant T. longispinosus is involved in this process: using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg but falls into a separate Vg-like A cluster. Secondly, an experimental knockdown of Vg-like A in the fat body caused a reduction in brood care and an increase in nestmate care in young ant workers. Nestmate care is normally exhibited by older workers. We demonstrate experimentally that this task switch is at least partly based on Vg-like A-associated shifts in responsiveness from brood to worker cues. We thus reveal a novel mechanism leading to early behavioral maturation via changes in social cue responsiveness mediated by Vg-like A and associated pathways, which proximately play a role in regulating division of labor.
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Affiliation(s)
- Philip Kohlmeier
- Institute of Organismic and Molecular and Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular and Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
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19
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Pamminger T, Botías C, Goulson D, Hughes WOH. A mechanistic framework to explain the immunosuppressive effects of neurotoxic pesticides on bees. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13119] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | - Christina Botías
- School of Life SciencesUniversity of Sussex Brighton UK
- Estación Biológica de Doñana (EBD‐CSIC) Seville Spain
| | - Dave Goulson
- School of Life SciencesUniversity of Sussex Brighton UK
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20
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Blacher P, Huggins TJ, Bourke AFG. Evolution of ageing, costs of reproduction and the fecundity-longevity trade-off in eusocial insects. Proc Biol Sci 2018; 284:rspb.2017.0380. [PMID: 28701554 PMCID: PMC5524490 DOI: 10.1098/rspb.2017.0380] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/07/2017] [Indexed: 01/04/2023] Open
Abstract
Eusocial insects provide special opportunities to elucidate the evolution of ageing as queens have apparently evaded costs of reproduction and reversed the fecundity–longevity trade-off generally observed in non-social organisms. But how reproduction affects longevity in eusocial insects has rarely been tested experimentally. In this study, we took advantage of the reproductive plasticity of workers to test the causal role of reproduction in determining longevity in eusocial insects. Using the eusocial bumblebee Bombus terrestris, we found that, in whole colonies, in which workers could freely ‘choose’ whether to become reproductive, workers' level of ovarian activation was significantly positively associated with longevity and ovary-active workers significantly outlived ovary-inactive workers. By contrast, when reproductivity was experimentally induced in randomly selected workers, thereby decoupling it from other traits, workers' level of ovarian activation was significantly negatively associated with longevity and ovary-active workers were significantly less long-lived than ovary-inactive workers. These findings show that workers experience costs of reproduction and suggest that intrinsically high-quality individuals can overcome these costs. They also raise the possibility that eusocial insect queens exhibit condition-dependent longevity and hence call into question whether eusociality entails a truly reversed fecundity–longevity trade-off involving a fundamental remodelling of conserved genetic and endocrine networks underpinning ageing.
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Affiliation(s)
- Pierre Blacher
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Timothy J Huggins
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Andrew F G Bourke
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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21
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Keiser CN, Vojvodic S, Butler IO, Sartain E, Rudolf VHW, Saltz JB. Queen presence mediates the relationship between collective behaviour and disease susceptibility in ant colonies. J Anim Ecol 2017; 87:379-387. [PMID: 28518216 DOI: 10.1111/1365-2656.12696] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 05/08/2017] [Indexed: 11/28/2022]
Abstract
The success of social living can be explained, in part, by a group's ability to execute collective behaviours unachievable by solitary individuals. However, groups vary in their ability to execute these complex behaviours, often because they vary in their phenotypic composition. Group membership changes over time due to mortality or emigration, potentially leaving groups vulnerable to ecological challenges in times of flux. In some societies, the loss of important individuals (e.g. leaders, elites and queens) may have an especially detrimental effect on groups' ability to deal with these challenges. Here, we test whether the removal of queens in colonies of the acorn ant Temnothorax curvispinosus alters their ability to execute important collective behaviours and survive outbreaks of a generalist entomopathogen. We employed a split-colony design where one half of a colony was maintained with its queen, while the other half was separated from the queen. We then tested these subcolonies' performance in a series of collective behaviour assays and finally exposed colonies to the entomopathogenic fungus Metarhizium robertsii by exposing two individuals from the colony and then sealing them back into the nest. We found that queenright subcolonies outperformed their queenless counterparts in nearly all collective behaviours. Queenless subcolonies were also more vulnerable to mortality from disease. However, queenless groups that displayed more interactions with brood experienced greater survivorship, a trend not present in queenright subcolonies. Queenless subcolonies that engage in more brood interactions may have had more resources available to cope with two physiological challenges (ovarian development after queen loss and immune activation after pathogen exposure). Our results indicate that queen presence can play an integral role in colony behaviour, survivorship and their relationship. They also suggest that interactions between workers and brood are integral to colonies survival. Overall, a social group's history of social reorganization may have strong consequences on their collective behaviours and their vulnerability to disease outbreaks.
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Affiliation(s)
- Carl N Keiser
- Rice University Academy of Fellows, Rice University, Houston, TX, USA.,Department of Biosciences, Rice University, Houston, TX, USA
| | | | - Imani O Butler
- Department of Biosciences, Rice University, Houston, TX, USA
| | | | | | - Julia B Saltz
- Department of Biosciences, Rice University, Houston, TX, USA
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22
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Pamminger T, Buttstedt A, Norman V, Schierhorn A, Botías C, Jones JC, Basley K, Hughes WOH. The effects of juvenile hormone on Lasius niger reproduction. JOURNAL OF INSECT PHYSIOLOGY 2016; 95:1-7. [PMID: 27614175 DOI: 10.1016/j.jinsphys.2016.09.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/05/2016] [Accepted: 09/05/2016] [Indexed: 06/06/2023]
Abstract
Reproduction has been shown to be costly for survival in a wide diversity of taxa. The resulting trade-off, termed the reproduction-survival trade-off, is thought to be one of the most fundamental forces of life-history evolution. In insects the pleiotropic effect of juvenile hormone (JH), antagonistically regulating reproduction and pathogen resistance, is suggested to underlie this phenomenon. In contrast to the majority of insects, reproductive individuals in many eusocial insects defy this trade-off and live both long and prosper. By remodelling the gonadotropic effects of JH in reproductive regulation, the queens of the long-lived black garden ant Lasius niger (living up to 27 years), have circumvented the reproduction-survival trade off enabling them to maximize both reproduction and pathogen resistance simultaneously. In this study we measure fertility, vitellogenin gene expression and protein levels after experimental manipulation of hormone levels. We use these measurements to investigate the mechanistic basis of endocrinological role remodelling in reproduction and determine how JH suppresses reproduction in this species, rather then stimulating it, like in the majority of insects. We find that JH likely inhibits three key aspects of reproduction both during vitellogenesis and oogenesis, including two previously unknown mechanisms. In addition, we document that juvenile hormone, as in the majority of insects, has retained some stimulatory function in regulating vitellogenin expression. We discuss the evolutionary consequences of this complex regulatory architecture of reproduction in L. niger, which might enable the evolution of similar reproductive phenotypes by alternate regulatory pathways, and the surprising flexibility regulatory role of juvenile hormone in this process.
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Affiliation(s)
- T Pamminger
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
| | - A Buttstedt
- Institut Für Biologie, Molekulare Ökologie, Martin-Luther-Universität Halle-Wittenberg, Halle 06099, Germany
| | - V Norman
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - A Schierhorn
- Institut Für Biochemie, Martin-Luther-Universität Halle Wittenberg, Halle 06099, Germany
| | - C Botías
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - J C Jones
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - K Basley
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - W O H Hughes
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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23
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Abstract
The sterile worker castes found in the colonies of social insects are often cited as archetypal examples of altruism in nature. The challenge is to explain why losing the ability to mate has evolved as a superior strategy for transmitting genes into future generations. We propose that two conditions are necessary for the evolution of sterility: completely overlapping generations and monogamy. A review of the literature indicates that when these two conditions are met we consistently observe the evolution of sterile helpers. We explain the theory and evidence behind these ideas, and discuss the importance of ecology in predicting whether sterility will evolve using examples from social birds, mammals, and insects. In doing so, we offer an explanation for the extraordinary lifespans of some cooperative species which hint at ways in which we can unlock the secrets of long life.
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24
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Pamminger T, Hughes WOH. Testing the reproductive groundplan hypothesis in ants (Hymenoptera: Formicidae). Evolution 2016; 71:153-159. [DOI: 10.1111/evo.13105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 10/16/2016] [Accepted: 10/20/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Tobias Pamminger
- School of Life Sciences; University of Sussex; Falmer Brighton BN1 9QG United Kingdom
| | - William O. H. Hughes
- School of Life Sciences; University of Sussex; Falmer Brighton BN1 9QG United Kingdom
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25
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de Verges J, Nehring V. A critical look at proximate causes of social insect senescence: damage accumulation or hyperfunction? CURRENT OPINION IN INSECT SCIENCE 2016; 16:69-75. [PMID: 27720053 DOI: 10.1016/j.cois.2016.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/26/2016] [Accepted: 05/02/2016] [Indexed: 06/06/2023]
Abstract
Social insects have received attention for their extreme lifespan variation and reversal of the fecundity/longevity trade-off. However, proximate causes of senescence in general are disputed, and social insects often fail to meet the predictions of prevailing models. We present evidence for and against the long-held free radical theory of aging in social insects, and consider the application of the competing hyperfunction theory. Current results present problems for both theories, and a more complex picture of the biological processes involved emerges. The eusocial life style might allow colonies to allocate damage in ways that create seemingly senescence-free life histories. Only experimental approaches characterizing multiple senescence factors simultaneously will shed light on how social insects defy the conventions of senescence.
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Affiliation(s)
- Jane de Verges
- University of Freiburg, Biology I, Evolution & Ecology, Hauptstraße 1, D-79104 Freiburg, Germany
| | - Volker Nehring
- University of Freiburg, Biology I, Evolution & Ecology, Hauptstraße 1, D-79104 Freiburg, Germany.
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26
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Séguret A, Bernadou A, Paxton RJ. Facultative social insects can provide insights into the reversal of the longevity/fecundity trade-off across the eusocial insects. CURRENT OPINION IN INSECT SCIENCE 2016; 16:95-103. [PMID: 27720058 DOI: 10.1016/j.cois.2016.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 05/27/2016] [Accepted: 06/03/2016] [Indexed: 06/06/2023]
Abstract
In eusocial insects, reversal of the fecundity/longevity trade-off and extreme differences in life histories between castes of the same species garner scientific and public interest. Facultative social species at the threshold of sociality, in which individuals are socially plastic, provide an excellent opportunity to understand the causes and mechanisms underlying this reversal in life history trade-off associated with eusociality. We briefly present the ultimate factors favoring sociality and the association between fecundity and longevity in facultative eusocial insects, including kin selection and disposable soma, as well as proximate mechanisms observed in such species, such as differences in hormone titers and functions. Potential genetic underpinnings of lifespan and fecundity differences between castes are discussed and future research directions are proposed.
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Affiliation(s)
- Alice Séguret
- Institute for Biology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Abel Bernadou
- Zoology/Evolutionary Biology, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Robert J Paxton
- Institute for Biology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany; iDiv, German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.
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27
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Kramer BH, van Doorn GS, Weissing FJ, Pen I. Lifespan divergence between social insect castes: challenges and opportunities for evolutionary theories of aging. CURRENT OPINION IN INSECT SCIENCE 2016; 16:76-80. [PMID: 27720054 DOI: 10.1016/j.cois.2016.05.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/09/2016] [Accepted: 05/11/2016] [Indexed: 06/06/2023]
Abstract
The extraordinarily long lifespans of queens (and kings) in eusocial insects and the strikingly large differences in life expectancy between workers and queens challenge our understanding of the evolution of aging and provide unique opportunities for studying the causes underlying adaptive variation in lifespan within species. Here we review the major evolutionary theories of aging, focusing on their scope and limitations when applied to social insects. We show that reproductive division of labor, interactions between kin, caste-specific gene regulation networks, and the integration of colony-level trade-offs with individual-level trade-offs provide challenges to the classical theories We briefly indicate how these challenges could be met in future models of adaptive phenotypic plasticity in lifespan between and within different castes.
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Affiliation(s)
- Boris H Kramer
- Theoretical Research in Evolutionary Life Sciences, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
| | - G Sander van Doorn
- Theoretical Research in Evolutionary Life Sciences, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Franz J Weissing
- Theoretical Research in Evolutionary Life Sciences, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Ido Pen
- Theoretical Research in Evolutionary Life Sciences, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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