1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Lin S, Elsner D, Ams L, Korb J, Rosengaus R. A genetic toolkit underlying the queen phenotype in termites with totipotent workers. Sci Rep 2024; 14:2214. [PMID: 38278833 PMCID: PMC10817970 DOI: 10.1038/s41598-024-51772-7] [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: 09/21/2023] [Accepted: 01/09/2024] [Indexed: 01/28/2024] Open
Abstract
Social insect castes (e.g., queens, workers) are prime examples of phenotypic plasticity (i.e., different phenotypes arising from the same genotype). Yet, the mechanisms that give rise to highly fertile, long-lived queens versus non-reproducing, short-lived workers are not well understood. Recently, a module of co-expressed genes has been identified that characterizes queens compared to workers of the termite Cryptotermes secundus (Kalotermitidae): the Queen Central Module (QCM). We tested whether the QCM is shared in termite species, in which queens gradually develop via early larval and late larval instars, the latter functioning as totipotent workers (linear development). Similar as in C. secundus, gene expression profiles revealed an enrichment of QCM genes in Zootermopsis angusticollis queens, a species from another termite family (Archotermopsidae). The expression of these QCM genes became gradually enriched during development from early larval instars via workers to queens. Thus, our results support the hypothesis of a conserved genetic toolkit that characterizes termite queens with gradual linear development. Our data also imply a strong caste-specific tissue specificity with the QCM signal being restricted to head-prothorax tissues in termite queens. This tissue-specific expression of key aging-related genes might have facilitated the evolution of a long lifespan in termite queens.
Collapse
Affiliation(s)
- Silu Lin
- Evolutionary Biology and Ecology, University of Freiburg, 79104, Freiburg, Germany
| | - Daniel Elsner
- Evolutionary Biology and Ecology, University of Freiburg, 79104, Freiburg, Germany
| | - Leon Ams
- Evolutionary Biology and Ecology, University of Freiburg, 79104, Freiburg, Germany
| | - Judith Korb
- Evolutionary Biology and Ecology, University of Freiburg, 79104, Freiburg, Germany.
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina Campus, Darwin, NT, 0909, Australia.
| | - Rebeca Rosengaus
- Department of Marine and Environmental Sciences, Northeastern University, Boston, MA, 02115, USA.
| |
Collapse
|
3
|
Chen J, Setia G, Lin LH, Sun Q, Husseneder C. Weight and protozoa number but not bacteria diversity are associated with successful pair formation of dealates in the Formosan subterranean termite, Coptotermes formosanus. PLoS One 2023; 18:e0293813. [PMID: 37956140 PMCID: PMC10642788 DOI: 10.1371/journal.pone.0293813] [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: 07/20/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
New colonies of Formosan subterranean termites are founded by monogamous pairs. During swarming season, alates (winged reproductives) leave their parental colony. After swarming, they drop to the ground, shed their wings, and male and female dealates find suitable nesting sites where they mate and become kings and queens of new colonies. The first generation of offspring is entirely dependent on the nutritional resources of the founder pair consisting of the fat and protein reserves of the dealates and their microbiota, which include the cellulose-digesting protozoa and diverse bacteria. Since termite kings and queens can live for decades, mate for life and colony success is linked to those initial resources, we hypothesized that gut microbiota of founders affect pair formation. To test this hypothesis, we collected pairs found in nest chambers and single male and female dealates from four swarm populations. The association of three factors (pairing status, sex of the dealates and population) with dealate weights, total protozoa, and protozoa Pseudotrichonympha grassii numbers in dealate hindguts was determined. In addition, Illumina 16S rRNA gene sequencing and the QIIME2 pipeline were used to determine the impact of those three factors on gut bacteria diversity of dealates. Here we report that pairing status was significantly affected by weight and total protozoa numbers, but not by P. grassii numbers and bacteria diversity. Weight and total protozoa numbers were higher in paired compared to single dealates. Males contained significantly higher P. grassii numbers and bacteria richness and marginally higher phylogenetic diversity despite having lower weights than females. In conclusion, this study showed that dealates with high body weight and protozoa numbers are more likely to pair and become colony founders, probably because of competitive advantage. The combined nutritional resources provided by body weight and protozoa symbionts of the parents are important for successful colony foundation and development.
Collapse
Affiliation(s)
- Junyan Chen
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Garima Setia
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Li-Hsiang Lin
- Department of Experimental Statistics, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Qian Sun
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Claudia Husseneder
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| |
Collapse
|
4
|
Padget RFB, Cant MA, Thompson FJ. Us, them, and the others: Testing for discrimination amongst outgroups in a single‐piece nesting termite, Zootermopsis angusticollis. Ecol Evol 2023; 13:e9901. [PMID: 36960235 PMCID: PMC10030232 DOI: 10.1002/ece3.9901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/01/2023] [Accepted: 02/20/2023] [Indexed: 03/23/2023] Open
Abstract
Recognition of group members is an important adaptation in social organisms because it allows help to be directed toward kin or individuals that are likely to reciprocate, and harm to be directed toward members of competing groups. Evidence in a wide range of animals shows that responses to outgroups vary with context, suggesting that cues to group membership also depend on the social or environmental context. In termites, intergroup encounters are frequent and their outcomes highly variable, ranging from destruction of a colony to colony fusion. As well as genetic factors, nestmate recognition in social insects commonly relies on cues that are mediated by environmental factors such as food source. However, single‐piece nesting termite colonies share nesting material and food source with rival colonies (their wood substrate serves as both). In principle, the shared environment of single‐piece nesting termite colonies could constrain their ability to identify non‐nestmates, contributing to some of the variation seen in encounters, but this has not been investigated. In this study, we raised incipient colonies of a single‐piece nesting termite, Zootermopsis angusticollis, on two different wood types and conducted behavioral assays to test whether nestmate discrimination can be constrained by common environmental conditions. We found that non‐nestmates elicited higher rates of identity checking and defense behavior compared to nestmates, but there was no effect of wood type on the strength of behavioral responses to non‐nestmates. We also found that one key cooperative behavior (allogrooming) was performed equally toward both nestmates and non‐nestmates. These findings offer no support for the hypothesis that common wood type constrains the nestmate recognition system of single piece nesting termites. We suggest that where groups encounter each other frequently in a common environment, selection will favor discrimination based on genetic and/or higher resolution environmentally mediated cues.
Collapse
Affiliation(s)
- Rebecca F. B. Padget
- Centre for Ecology and Conservation, College of Life and Environmental SciencesUniversity of ExeterCornwallUK
- Centre for Research in Animal Behaviour, College of Life and Environmental SciencesUniversity of ExeterExeterUK
| | - Michael A. Cant
- Centre for Ecology and Conservation, College of Life and Environmental SciencesUniversity of ExeterCornwallUK
- German Primate CenterUniversity of GoettingenGoettingenGermany
| | - Faye J. Thompson
- Centre for Ecology and Conservation, College of Life and Environmental SciencesUniversity of ExeterCornwallUK
| |
Collapse
|
5
|
Recart W, Bernhard R, Ng I, Garcia K, Fleming-Davies AE. Meta-Analysis of the Effects of Insect Pathogens: Implications for Plant Reproduction. Pathogens 2023; 12:pathogens12020347. [PMID: 36839619 PMCID: PMC9958737 DOI: 10.3390/pathogens12020347] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/11/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Despite extensive work on both insect disease and plant reproduction, there is little research on the intersection of the two. Insect-infecting pathogens could disrupt the pollination process by affecting pollinator population density or traits. Pathogens may also infect insect herbivores and change herbivory, potentially altering resource allocation to plant reproduction. We conducted a meta-analysis to (1) summarize the literature on the effects of pathogens on insect pollinators and herbivores and (2) quantify the extent to which pathogens affect insect traits, with potential repercussions for plant reproduction. We found 39 articles that fit our criteria for inclusion, extracting 218 measures of insect traits for 21 different insect species exposed to 25 different pathogens. We detected a negative effect of pathogen exposure on insect traits, which varied by host function: pathogens had a significant negative effect on insects that were herbivores or carried multiple functions but not on insects that solely functioned as pollinators. Particular pathogen types were heavily studied in certain insect orders, with 7 of 11 viral pathogen studies conducted in Lepidoptera and 5 of 9 fungal pathogen studies conducted in Hymenoptera. Our results suggest that most studies have focused on a small set of host-pathogen pairs. To understand the implications for plant reproduction, future work is needed to directly measure the effects of pathogens on pollinator effectiveness.
Collapse
Affiliation(s)
- Wilnelia Recart
- Biology Department, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
- Correspondence:
| | - Rover Bernhard
- Biology Department, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
- Biology Department, Lewis and Clark College, 615 S. Palatine Hill Road, Portland, OR 97219, USA
| | - Isabella Ng
- Biology Department, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
| | - Katherine Garcia
- Biology Department, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
- Environmental Sciences Department, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0021, USA
| | | |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Intersection between parental investment, transgenerational immunity, and termite sociality in the face of disease: a theoretical approach. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03128-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
8
|
Casillas-Pérez B, Pull CD, Naiser F, Naderlinger E, Matas J, Cremer S. Early queen infection shapes developmental dynamics and induces long-term disease protection in incipient ant colonies. Ecol Lett 2021; 25:89-100. [PMID: 34725912 PMCID: PMC9298059 DOI: 10.1111/ele.13907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 11/30/2022]
Abstract
Infections early in life can have enduring effects on an organism's development and immunity. In this study, we show that this equally applies to developing 'superorganisms'--incipient social insect colonies. When we exposed newly mated Lasius niger ant queens to a low pathogen dose, their colonies grew more slowly than controls before winter, but reached similar sizes afterwards. Independent of exposure, queen hibernation survival improved when the ratio of pupae to workers was small. Queens that reared fewer pupae before worker emergence exhibited lower pathogen levels, indicating that high brood rearing efforts interfere with the ability of the queen's immune system to suppress pathogen proliferation. Early-life queen pathogen exposure also improved the immunocompetence of her worker offspring, as demonstrated by challenging the workers to the same pathogen a year later. Transgenerational transfer of the queen's pathogen experience to her workforce can hence durably reduce the disease susceptibility of the whole superorganism.
Collapse
Affiliation(s)
| | - Christopher D Pull
- IST Austria (Institute of Science and Technology Austria), Klosterneuburg, Austria
| | - Filip Naiser
- Department of Cybernetics, Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic
| | | | - Jiri Matas
- Department of Cybernetics, Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic
| | - Sylvia Cremer
- IST Austria (Institute of Science and Technology Austria), Klosterneuburg, Austria
| |
Collapse
|
9
|
Gordon JM, Šobotník J, Chouvenc T. Colony-age-dependent variation in cuticular hydrocarbon profiles in subterranean termite colonies. Ecol Evol 2020; 10:10095-10104. [PMID: 33005366 PMCID: PMC7520186 DOI: 10.1002/ece3.6669] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/11/2020] [Accepted: 07/20/2020] [Indexed: 01/22/2023] Open
Abstract
Cuticular hydrocarbons (CHCs) have, in insects, important physiological and ecological functions, such as protection against desiccation and as semiochemicals in social taxa, including termites. CHCs are, in termites, known to vary qualitatively and/or quantitatively among species, populations, castes, or seasons. Changes to hydrocarbon profile composition have been linked to varying degrees of aggression between termite colonies, although the variability of results among studies suggests that additional factors might have been involved. One source of such variability may be colony age, as termite colony demographics significantly change over time, with different caste and instar compositions throughout the life of the colony. We here hypothesize that the intracolonial chemical profile heterogeneity would be high in incipient termite colonies but would homogenize over time as a colony ages and accumulates older workers in improved homeostatic conditions. We studied caste-specific patterns of CHC profiles in Coptotermes gestroi colonies of four different age classes (6, 18, 30, and 42 months). The CHC profiles were variable among castes in the youngest colonies, but progressively converged toward a colony-wide homogenized chemical profile. Young colonies had a less-defined CHC identity, which implies a potentially high acceptance threshold for non-nestmates conspecifics in young colonies. Our results also suggest that there was no selective pressure for an early-defined colony CHC profile to evolve in termites, potentially allowing an incipient colony to merge nonagonistically with another conspecific incipient colony, with both colonies indirectly and passively avoiding mutual destruction as a result.
Collapse
Affiliation(s)
- Johnalyn M. Gordon
- Entomology and Nematology DepartmentFt. Lauderdale Research and Education CenterInstitute of Food and Agricultural SciencesUniversity of FloridaDavieFLUSA
| | - Jan Šobotník
- Faculty of Tropical AgriSciencesCULSPragueCzech Republic
| | - Thomas Chouvenc
- Entomology and Nematology DepartmentFt. Lauderdale Research and Education CenterInstitute of Food and Agricultural SciencesUniversity of FloridaDavieFLUSA
| |
Collapse
|
10
|
Cole EL, Bayne H, Rosengaus RB. Young but not defenceless: antifungal activity during embryonic development of a social insect. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191418. [PMID: 32968491 PMCID: PMC7481685 DOI: 10.1098/rsos.191418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 07/27/2020] [Indexed: 05/16/2023]
Abstract
Termites live in environments heavily colonized by diverse microorganisms, including pathogens. Eggs laid within the nest are likely to experience similar pathogenic pressures as those experienced by older nest-mates. Consequently, eggs may be under selective pressures to be immune-competent. Through in vitro experiments using developing embryos of the dampwood termite, Zootermopsis angusticollis, we tested the ontogeny, location and strength of their antifungal activity against the fungus, Metarhizium brunneum. Exterior washes of the chorion (extra-chorionic) and components within the chorion (intra-chorionic) were incubated with fungal conidia, which were then scored for viability. The fungistatic activity was location and developmental stage dependent. Extra-chorionic washes had relatively weak antifungal activity. Intra-chorionic homogenates were highly antifungal, exhibiting increased potency through development. The positive correlation between intra-chorionic fungistasis and developmental stage is probably due to the expression of endogenous proteins during embryogenesis. Boiling of both the extra-chorionic washes and the intra-chorionic contents rescued conidia viability, indicating the antifungal agent(s) is (are) heat-sensitive and probably proteinaceous. This study is the first to address embryonic antifungal activity in a hemimetabolous, eusocial taxon. Our results support the hypothesis that microbes have been significant agents of selection in termites, fostering the evolution of antifungal properties even in the most immature stage of development.
Collapse
|
11
|
Thompson FJ, Hunt KL, Wright K, Rosengaus RB, Cole EL, Birch G, Maune AL, Cant MA. Who goes there? Social surveillance as a response to intergroup conflict in a primitive termite. Biol Lett 2020. [PMCID: PMC7423038 DOI: 10.1098/rsbl.2020.0131] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Intergroup conflict has been suggested as a major force shaping the evolution of social behaviour in animal groups. A long-standing hypothesis is that groups at risk of attack by rivals should become more socially cohesive, to increase resilience or protect against future attack. However, it is usually unclear how cohesive behaviours (such as grooming or social contacts) function in intergroup conflict. We performed an experiment in which we exposed young colonies of the dampwood termite,
Zootermopsis angusticollis
, to a rival colony while preventing physical combat with a permeable barrier. We measured social contacts, allogrooming and trophallaxis before, during and after exposure. Termites showed elevated rates of social contacts during exposure to a rival compared to the pre-exposure phase, but rates returned to pre-exposure levels after colonies were separated for 9 days. There was evidence of a delayed effect of conflict on worker trophallaxis. We suggest that social contacts during intergroup conflict function as a form of social surveillance, to check individual identity and assess colony resource holding potential. Intergroup conflict may increase social cohesion in both the short and the long term, improving the effectiveness of groups in competition.
Collapse
Affiliation(s)
- Faye J. Thompson
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Kingsley L. Hunt
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Kallum Wright
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Rebeca B. Rosengaus
- Department of Marine and Environmental Sciences, Northeastern University, Boston, MA 02115, USA
| | - Erin L. Cole
- Department of Marine and Environmental Sciences, Northeastern University, Boston, MA 02115, USA
| | - Graham Birch
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Avery L. Maune
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Michael A. Cant
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| |
Collapse
|
12
|
Tragust S, Brinker P, Rossel N, Otti O. Balancing Life History Investment Decisions in Founding Ant Queens. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
13
|
Aguero CM, Eyer PA, Vargo EL. Increased genetic diversity from colony merging in termites does not improve survival against a fungal pathogen. Sci Rep 2020; 10:4212. [PMID: 32144325 PMCID: PMC7060273 DOI: 10.1038/s41598-020-61278-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 02/24/2020] [Indexed: 12/26/2022] Open
Abstract
In some species of social insects the increased genetic diversity from having multiple breeders in a colony has been shown to improve pathogen resistance. Termite species typically found colonies from single mated pairs and therefore may lack the flexibility to buffer pathogen pressure with increased genetic diversity by varying the initial number of reproductives. However, they can later increase group diversity through colony merging, resulting in a genetically diverse, yet cohesive, workforce. In this study, we investigate whether the increased group diversity from colony fusion benefits social immunity in the subterranean termite Reticulitermes flavipes. We confirm previous findings that colonies of R. flavipes will readily merge and we show that workers will equally groom nestmates and non-nestmates after merging. Despite this, the survival of these merged colonies was not improved after exposure to a fungal pathogen, but instead leveled to that of the more susceptible or the more resistant colony. Our study brings little support to the hypothesis that colony fusion may improve immunity through an increase of genetic diversity in R. flavipes. Instead, we find that following exposure to a lethal pathogen, one colony is heavily influential to the entire group's survival after merging.
Collapse
Affiliation(s)
- Carlos M Aguero
- Department of Entomology, 2143 TAMU, Texas A&M University, College Station, Texas, 77843-2143, USA.
| | - Pierre-André Eyer
- Department of Entomology, 2143 TAMU, Texas A&M University, College Station, Texas, 77843-2143, USA
| | - Edward L Vargo
- Department of Entomology, 2143 TAMU, Texas A&M University, College Station, Texas, 77843-2143, USA
| |
Collapse
|
14
|
Cole EL, Empringham JS, Biro C, Thompson GJ, Rosengaus RB. Relish as a Candidate Marker for Transgenerational Immune Priming in a Dampwood Termite (Blattodae: Archeotermopsidae). INSECTS 2020; 11:E149. [PMID: 32120840 PMCID: PMC7143124 DOI: 10.3390/insects11030149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 11/17/2022]
Abstract
Natural selection should favor the transfer of immune competence from one generation to the next in a context-dependent manner. Transgenerational immune priming (TGIP) is expected to evolve when species exploit pathogen-rich environments and exhibit extended overlap of parent-offspring generations. Dampwood termites are hemimetabolous, eusocial insects (Blattodea: Archeotermopsidae) that possess both of these traits. We predict that offspring of pathogen-exposed queens of Zootermopsis angusticollis will show evidence of a primed immune system relative to the offspring of unexposed controls. We found that Relish transcripts, one of two immune marker loci tested, were enhanced in two-day-old embryos when laid by Serratia-injected queens. These data implicate the immune deficiency (IMD) signaling pathway in TGIP. Although an independent antibacterial assay revealed that embryos do express antibacterial properties, these do not vary as a function of parental treatment. Taken together, Z. angusticollis shows transcriptional but not translational evidence for TGIP. This apparent incongruence between the transcriptional and antimicrobial response from termites suggests that effectors are either absent in two-day-old embryos or their activity is too subtle to detect with our antibacterial assay. In total, we provide the first suggestive evidence of transgenerational immune priming in a termite.
Collapse
Affiliation(s)
- Erin L. Cole
- Department of Marine and Environmental Sciences, Northeastern University, 134 Mugar Life Sciences Building, 360 Huntington Avenue, Boston, MA 02115, USA; (E.L.C.); (C.B.)
| | - Jessica S. Empringham
- Department of Biology, Western University, 1151 Richmond St. London, ON N6A 5B7, Canada; (J.S.E.); (G.J.T.)
| | - Colette Biro
- Department of Marine and Environmental Sciences, Northeastern University, 134 Mugar Life Sciences Building, 360 Huntington Avenue, Boston, MA 02115, USA; (E.L.C.); (C.B.)
| | - Graham J. Thompson
- Department of Biology, Western University, 1151 Richmond St. London, ON N6A 5B7, Canada; (J.S.E.); (G.J.T.)
| | - Rebeca B. Rosengaus
- Department of Marine and Environmental Sciences, Northeastern University, 134 Mugar Life Sciences Building, 360 Huntington Avenue, Boston, MA 02115, USA; (E.L.C.); (C.B.)
| |
Collapse
|
15
|
Cole EL, Rosengaus RB. Pathogenic Dynamics During Colony Ontogeny Reinforce Potential Drivers of Termite Eusociality: Mate Assistance and Biparental Care. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00473] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|