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Hellemans S, Hanus R. Termite primary queen - ancestral, but highly specialized eusocial phenotype. CURRENT OPINION IN INSECT SCIENCE 2024; 61:101157. [PMID: 38142979 DOI: 10.1016/j.cois.2023.101157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/20/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023]
Abstract
Termite eusociality is accompanied by flagrant caste polyphenism manifested by the presence of several sterile (workers and soldiers) and reproductive (imaginal and neotenic kings and queens) caste phenotypes. Imaginal kings and queens are developmentally equivalent to adults of other hemimetabolous insects but display multiple adaptations inherent to their role of eusocial colony founders, such as long lifespan and high fecundity. Herein, we summarize the recent advances in understanding the biology of imaginal (primary) queens as emblematic examples of termite polyphenism acquired during social evolution. We focus on the control of queen development, on dynamics in physiology and fecundity during the queen's life, on new findings about queen fertility signaling, and on proximate mechanisms underlying queen longevity.
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Affiliation(s)
- Simon Hellemans
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; Evolutionary Biology and Ecology, Université libre de Bruxelles, 50 avenue F.D. Roosevelt, 1050 Brussels, Belgium
| | - Robert Hanus
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 160 00 Prague, Czech Republic.
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Ruhland F, Gabant G, Toussaint T, Nemcic M, Cadène M, Lucas C. Reproductives signature revealed by protein profiling and behavioral bioassays in termite. Sci Rep 2023; 13:7070. [PMID: 37127756 PMCID: PMC10151321 DOI: 10.1038/s41598-023-33252-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 04/10/2023] [Indexed: 05/03/2023] Open
Abstract
Proteins are known to be social interaction signals in many species in the animal kingdom. Common mediators in mammals and aquatic species, they have seldom been identified as such in insects' behaviors. Yet, they could represent an important component to support social signals in social insects, as the numerous physical contacts between individuals would tend to favor the use of contact compounds in their interactions. However, their role in social interactions is largely unexplored: are they rare or simply underestimated? In this preliminary study, we show that, in the termite Reticulitermes flavipes, polar extracts from reproductives trigger body-shaking of workers (a vibratory behavior involved in reproductives recognition) while extracts from workers do not. Molecular profiling of these cuticular extracts using MALDI-TOF mass spectrometry reveals higher protein diversity in reproductives than in workers and a sex-specific composition exclusive to reproductives. While the effects observed with extracts are not as strong as with live termites, these results open up the intriguing possibility that social signaling may not be limited to cuticular hydrocarbons or other non-polar, volatile chemicals as classically accepted. Our results suggest that polar compounds, in particular some of the Cuticular Protein Compounds (CPCs) shown here by MALDI to be specific to reproductives, could play a significant role in insect societies. While this study is preliminary and further comprehensive molecular characterization is needed to correlate the body-shaking triggering effects with a given set of polar compounds, this exploratory study opens new perspectives for understanding the role of polar compounds such as proteins in caste discrimination, fertility signaling, or interspecific insect communication.
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Affiliation(s)
- Fanny Ruhland
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France
| | - Guillaume Gabant
- Centre de Biophysique Moléculaire (UPR 4301), CNRS - University of Orléans, Orléans, France
| | - Timothée Toussaint
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France
| | - Matej Nemcic
- Centre de Biophysique Moléculaire (UPR 4301), CNRS - University of Orléans, Orléans, France
| | - Martine Cadène
- Centre de Biophysique Moléculaire (UPR 4301), CNRS - University of Orléans, Orléans, France
| | - Christophe Lucas
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France.
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Dolejšová K, Křivánek J, Štáfková J, Horáček N, Havlíčková J, Roy V, Kalinová B, Roy A, Kyjaková P, Hanus R. Identification of a queen primer pheromone in higher termites. Commun Biol 2022; 5:1165. [PMID: 36323794 PMCID: PMC9630296 DOI: 10.1038/s42003-022-04163-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022] Open
Abstract
It is long established that queens of social insects, including termites, maintain their reproductive dominance with queen primer pheromones (QPPs). Yet, the QPP chemistry has only been elucidated in a single species of lower termites. By contrast, the most diversified termite family Termitidae (higher termites), comprising over 70% of termite species, has so far resisted all attempts at QPP identification. Here, we show that the queen- and egg-specific sesquiterpene (3R,6E)-nerolidol acts as the QPP in the higher termite Embiratermes neotenicus. This species has a polygynous breeding system, in which the primary queen is replaced by multiple neotenic queens of parthenogenetic origin. We demonstrate that (3R,6E)-nerolidol suppresses the development of these parthenogenetic queens and thus mimics the presence of mature queen(s). It acts as an airborne signal and may be used to optimize the number of queens, thus being the key regulatory element in the special breeding system of E. neotenicus.
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Affiliation(s)
- Klára Dolejšová
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, Charles University, Prague, Czech Republic
| | - Jan Křivánek
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jitka Štáfková
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Natan Horáček
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, Charles University, Prague, Czech Republic
| | - Jana Havlíčková
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Virginie Roy
- Université Paris Est Créteil, Sorbonne Université, Université Paris Cité, CNRS, INRAE, IRD, iEES Paris, Créteil, France
| | | | - Amit Roy
- Czech University of Life Sciences, Prague, Czech Republic
| | - Pavlína Kyjaková
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Robert Hanus
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic.
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Moran MN, Aguero CM, Eyer PA, Vargo EL. Rescue Strategy in a Termite: Workers Exposed to a Fungal Pathogen Are Reintegrated Into the Colony. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.840223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Social insect colonies are characterized by an efficient division of labor, allowing high-value individuals (i.e., reproductives and brood) to be sheltered from tasks associated with increased risk of pathogen exposure, such as foraging or corpse disposal. This social organization helps limit the transmission of disease throughout the colony. Further, individuals can actively respond to imminent disease threats by altering their behaviors as a means of social immunity. In subterranean termites, although workers typically avoid detected pathogens, they can be attracted to pathogen cues when a nestmate is infected. Infected termites are usually groomed, but they may instead be cannibalized if the infection has already become lethal. The mechanisms governing these changes in behavior are unclear. We set out to examine immediate changes in individual behaviors, investigating the role that the infected individual plays in communicating its infection status to nestmates. We also assessed gradual changes in social organization after the re-introduction of an infected termite to the colony. Our results reveal that infected termites likely do not signal their infection status to nestmates through shaking behaviors and reduced movements, suggesting the occurrence of other mechanisms used in communicating infection. We also found that infected termites do not self-isolate and may travel to the densest part of the colony, where they can potentially benefit from grooming by large groups of nestmates. These results provide new insights into how individual changes in immune behaviors contribute to overall colony health, highlighting that, at early stages of infection, termites favor a rescuing strategy rather than isolation and/or cannibalization.
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Eyer PA, Vargo EL. Short and long-term costs of inbreeding in the lifelong-partnership in a termite. Commun Biol 2022; 5:389. [PMID: 35469055 PMCID: PMC9038770 DOI: 10.1038/s42003-022-03317-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/24/2022] [Indexed: 11/24/2022] Open
Abstract
Social life and lifelong partner commitments are expected to favor thorough partner choice, as an ill-suited partnership may have long-term consequences, adversely affecting the parents and spanning several cohorts of offspring. Here, we used ~1400 termite incipient colonies to estimate the short- and long-term costs of inbreeding upon the survival of the parents over a 15-month period, their productivity, and the resistance of their offspring toward pathogen pressure. We observed that foundation success was not influenced by the relatedness of partners, but by their levels of microbial load. We showed faster growth in inbred colonies with low levels of microbial load, revealing a potential tradeoff between pathogen defense and offspring production. Yet, inbreeding takes its toll later in colony development when offspring from incipient colonies face pathogen pressure. Although the success of a lifetime partnership is initially determined by the partner’s health, the cost of inbreeding in incipient colonies favors outbred colonies reaching maturity. Studies of termite colonies over 15 months show that inbred colonies exhibit faster initial growth with low levels of microbial load, but higher mortality toward pathogens later in colony development.
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Affiliation(s)
- Pierre-André Eyer
- Department of Entomology, 2143 TAMU, Texas A&M University, College Station, TX, 77843-2143, USA.
| | - Edward L Vargo
- Department of Entomology, 2143 TAMU, Texas A&M University, College Station, TX, 77843-2143, USA
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Nanda MA, Seminar KB, Maddu A, Nandika D. Identifying relevant features of termite signals applied in termite detection system. ECOL INFORM 2021. [DOI: 10.1016/j.ecoinf.2021.101391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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