--- _id: '13984' abstract: - lang: eng text: "Social insects fight disease using their individual immune systems and the cooperative\r\nsanitary behaviors of colony members. These social defenses are well explored against\r\nexternally-infecting pathogens, but little is known about defense strategies against\r\ninternally-infecting pathogens, such as viruses. Viruses are ubiquitous and in the last decades\r\nit has become evident that also many ant species harbor viruses. We present one of the first\r\nstudies addressing transmission dynamics and collective disease defenses against viruses in\r\nants on a mechanistic level. I successfully established an experimental ant host – viral\r\npathogen system as a model for the defense strategies used by social insects against internal\r\npathogen infections, as outlined in the third chapter. In particular, we studied how garden ants\r\n(Lasius neglectus) defend themselves and their colonies against the generalist insect virus\r\nCrPV (cricket paralysis virus). We chose microinjections of virus directly into the ants’\r\nhemolymph because it allowed us to use a defined exposure dose. Here we show that this is a\r\ngood model system, as the virus is replicating and thus infecting the host. The ants mount a\r\nclear individual immune response against the viral infection, which is characterized by a\r\nspecific siRNA pattern, namely siRNAs mapping against the viral genome with a peak of 21\r\nand 22 bp long fragments. The onset of this immune response is consistent with the timeline\r\nof viral replication that starts already within two days post injection. The disease manifests in\r\ndecreased survival over a course of two to three weeks.\r\nRegarding group living, we find that infected ants show a strong individual immune response,\r\nbut that their course of disease is little affected by nestmate presence, as described in chapter\r\nfour. Hence, we do not find social immunity in the context of viral infections in ants.\r\nNestmates, however, can contract the virus. Using Drosophila S2R+ cells in culture, we\r\nshowed that 94 % of the nestmates contract active virus within four days of social contact to\r\nan infected individual. Virus is transmitted in low doses, thus not causing disease\r\ntransmission within the colony. While virus can be transmitted during short direct contacts,\r\nwe also assume transmission from deceased ants and show that the nestmates’ immune\r\nsystem gets activated after contracting a low viral dose. We find considerable potential for\r\nindirect transmission via the nest space. Virus is shed to the nest, where it stays viable for one\r\nweek and is also picked up by other ants. Apart from that, we want to underline the potential\r\nof ant poison as antiviral agent. We determined that ant poison successfully inactivates CrPV\r\nin vitro. However, we found no evidence for effective poison use to sanitize the nest space.\r\nOn the other hand, local application of ant poison by oral poison uptake, which is part of the\r\nants prophylactic behavioral repertoire, probably contributes to keeping the gut of each\r\nindividual sanitized. We hypothesize that oral poison uptake might be the reason why we did\r\nnot find viable virus in the trophallactic fluid.\r\nThe fifth chapter encompasses preliminary data on potential social immunization. However,\r\nour experiments do not confirm an actual survival benefit for the nestmates upon pathogen\r\nchallenge under the given experimental settings. Nevertheless, we do not want to rule out the\r\npossibility for nestmate immunization, but rather emphasize that considering different\r\nexperimental timelines and viral doses would provide a multitude of options for follow-up\r\nexperiments.\r\nIn conclusion, we find that prophylactic individual behaviors, such as oral poison uptake,\r\nmight play a role in preventing viral disease transmission. Compared to colony defense\r\nagainst external pathogens, internal pathogen infections require a stronger component of\r\nindividual physiological immunity than behavioral social immunity, yet could still lead to\r\ncollective protection." acknowledged_ssus: - _id: LifeSc alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Anna full_name: Franschitz, Anna id: 480826C8-F248-11E8-B48F-1D18A9856A87 last_name: Franschitz citation: ama: Franschitz A. Individual and social immunity against viral infections in ants. 2023. doi:10.15479/at:ista:13984 apa: Franschitz, A. (2023). Individual and social immunity against viral infections in ants. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:13984 chicago: Franschitz, Anna. “Individual and Social Immunity against Viral Infections in Ants.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:13984. ieee: A. Franschitz, “Individual and social immunity against viral infections in ants,” Institute of Science and Technology Austria, 2023. ista: Franschitz A. 2023. Individual and social immunity against viral infections in ants. Institute of Science and Technology Austria. mla: Franschitz, Anna. Individual and Social Immunity against Viral Infections in Ants. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:13984. short: A. Franschitz, Individual and Social Immunity against Viral Infections in Ants, Institute of Science and Technology Austria, 2023. date_created: 2023-08-08T15:33:29Z date_published: 2023-08-08T00:00:00Z date_updated: 2024-03-01T15:25:17Z day: '08' ddc: - '570' - '577' degree_awarded: PhD department: - _id: GradSch - _id: SyCr doi: 10.15479/at:ista:13984 file: - access_level: closed checksum: 27220243d5d51c3b0d7d61c0879d7a0c content_type: application/pdf creator: afransch date_created: 2023-08-08T18:01:28Z date_updated: 2024-03-01T08:51:42Z embargo: 2024-08-08 embargo_to: open_access file_id: '13986' file_name: Thesis_AnnaFranschitz_202308.pdf file_size: 10797612 relation: main_file - access_level: closed checksum: 40abf7ccca14a3893f72dc7fb88585d6 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: afransch date_created: 2023-08-08T18:02:25Z date_updated: 2023-08-09T07:25:27Z file_id: '13987' file_name: Thesis_AnnaFranschitz_202308.docx file_size: 2619085 relation: source_file - access_level: closed checksum: 8b991ecc2d59d045cc3cf0d676785ec7 content_type: application/pdf creator: cchlebak date_created: 2024-03-01T08:37:15Z date_updated: 2024-03-01T12:13:29Z description: Minor modifications and clarifications - Feb 2024 embargo: 2024-08-08 embargo_to: open_access file_id: '15042' file_name: Addendum_AnnaFranschitz202402.pdf file_size: 85956 relation: erratum title: Addendum - access_level: closed checksum: 66745aa01f960f17472c024875c049ed content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: cchlebak date_created: 2024-03-01T08:39:20Z date_updated: 2024-03-01T08:51:42Z file_id: '15043' file_name: Addendum_AnnaFranschitz202402.docx file_size: 11818 relation: source_file title: Addendum - source file - access_level: closed checksum: 55c876b73d49db15228a7f571592ec77 content_type: application/pdf creator: cchlebak date_created: 2024-03-01T08:56:06Z date_updated: 2024-03-01T12:58:14Z description: For printing purposes file_id: '15044' file_name: Print_Version_Franschitz_Anna_Thesis.pdf file_size: 10416761 relation: other title: Print Version file_date_updated: 2024-03-01T12:58:14Z has_accepted_license: '1' language: - iso: eng month: '08' oa_version: Published Version page: '89' publication_identifier: isbn: - 978-3-99078-034-3 issn: - 2663 - 337X publication_status: published publisher: Institute of Science and Technology Austria status: public supervisor: - first_name: Sylvia full_name: Cremer, Sylvia id: 2F64EC8C-F248-11E8-B48F-1D18A9856A87 last_name: Cremer orcid: 0000-0002-2193-3868 title: Individual and social immunity against viral infections in ants type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '10727' abstract: - lang: eng text: "Social insects are a common model to study disease dynamics in social animals. Even though pathogens should thrive in social insect colonies as the hosts engage in frequent social interactions, are closely related and live in a pathogen-rich environment, disease outbreaks are rare. This is because social insects have evolved mechanisms to keep pathogens at bay – and fight disease as a collective. Social insect colonies are often viewed as “superorganisms” with division of labor between reproductive “germ-like” queens and males and “somatic” workers, which together form an interdependent reproductive unit that parallels a multicellular body. Superorganisms possess a “social immune system” that comprises of collective disease defenses performed by the workers - summarized as “social immunity”. In social groups immunization (reduced susceptibility to a parasite upon secondary exposure to the same parasite) can e.g. be triggered by social interactions (“social immunization”). Social immunization can be caused by (i) asymptomatic low-level infections that are acquired during caregiving to a contagious individual that can give an immune boost, which can induce protection upon later encounter with the same pathogen (active immunization) or (ii) by transfer of immune effectors between individuals (passive immunization).\r\nIn the second chapter, I built up on a study that I co-authored that found that low-level infections can not only be protective, but also be costly and make the host more susceptible to detrimental superinfections after contact to a very dissimilar pathogen. I here now tested different degrees of phylogenetically-distant fungal strains of M. brunneum and M. robertsii in L. neglectus and can describe the occurrence of cross-protection of social immunization if the first and second pathogen are from the same level. Interestingly, low-level infections only provided protection when the first strain was less virulent than the second strain and elicited higher immune gene expression.\r\nIn the third and fourth chapters, I expanded on the role of social immunity in sexual selection, a so far unstudied field. I used the fungus Metarhizium robertsii and the ant Cardiocondyla obscurior as a model, as in this species mating occurs in the presence of workers and can be studied under laboratory conditions. Before males mate with virgin queens in the nest they engage in fierce combat over the access to their mating partners.\r\nFirst, I focused on male-male competition in the third chapter and found that fighting with a contagious male is costly as it can lead to contamination of the rival, but that workers can decrease the risk of disease contraction by performing sanitary care.\r\nIn the fourth chapter, I studied the effect of fungal infection on survival and mating success of sexuals (freshly emerged queens and males) and found that worker-performed sanitary care can buffer the negative effect that a pathogenic contagion would have on sexuals by spore removal from the exposed individuals. When social immunity was prevented and queens could contract spores from their mating partner, very low dosages led to negative consequences: their lifespan was reduced and they produced fewer offspring with poor immunocompetence compared to healthy queens. Interestingly, cohabitation with a late-stage infected male where no spore transfer was possible had a positive effect on offspring immunity – male offspring of mothers that apparently perceived an infected partner in their vicinity reacted more sensitively to fungal challenge than male offspring without paternal pathogen history." acknowledged_ssus: - _id: LifeSc alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Sina full_name: Metzler, Sina id: 48204546-F248-11E8-B48F-1D18A9856A87 last_name: Metzler orcid: 0000-0002-9547-2494 citation: ama: Metzler S. Pathogen-mediated sexual selection and immunization in ant colonies. 2022. doi:10.15479/AT:ISTA:10727 apa: Metzler, S. (2022). Pathogen-mediated sexual selection and immunization in ant colonies. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:10727 chicago: Metzler, Sina. “Pathogen-Mediated Sexual Selection and Immunization in Ant Colonies.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/AT:ISTA:10727. ieee: S. Metzler, “Pathogen-mediated sexual selection and immunization in ant colonies,” Institute of Science and Technology Austria, 2022. ista: Metzler S. 2022. Pathogen-mediated sexual selection and immunization in ant colonies. Institute of Science and Technology Austria. mla: Metzler, Sina. Pathogen-Mediated Sexual Selection and Immunization in Ant Colonies. Institute of Science and Technology Austria, 2022, doi:10.15479/AT:ISTA:10727. short: S. Metzler, Pathogen-Mediated Sexual Selection and Immunization in Ant Colonies, Institute of Science and Technology Austria, 2022. date_created: 2022-02-04T15:45:12Z date_published: 2022-02-07T00:00:00Z date_updated: 2023-09-07T13:43:23Z day: '07' ddc: - '570' degree_awarded: PhD department: - _id: GradSch - _id: SyCr doi: 10.15479/AT:ISTA:10727 ec_funded: 1 file: - access_level: closed checksum: 47ba18bb270dd6cc266e0a3f7c69d0e4 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: smetzler date_created: 2022-02-04T15:36:12Z date_updated: 2023-02-03T23:30:03Z embargo_to: open_access file_id: '10728' file_name: Thesis_Sina_Metzler.docx file_size: 6757886 relation: source_file - access_level: open_access checksum: f3ec07d5d6b20ae6e46bfeedebce9027 content_type: application/pdf creator: smetzler date_created: 2022-02-04T15:36:43Z date_updated: 2023-02-03T23:30:03Z embargo: 2023-02-02 file_id: '10730' file_name: Thesis_Sina_Metzler_A2.pdf file_size: 6314921 relation: main_file - access_level: open_access checksum: dedd14b7be7a75d63018dbfc68dd8113 content_type: application/pdf creator: smetzler date_created: 2022-02-07T10:35:02Z date_updated: 2023-02-04T23:30:03Z embargo: 2023-02-02 file_id: '10742' file_name: Thesis_Sina_Metzler_print.pdf file_size: 6882557 relation: main_file file_date_updated: 2023-02-04T23:30:03Z has_accepted_license: '1' language: - iso: eng month: '02' oa: 1 oa_version: Published Version project: - _id: 2649B4DE-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '771402' name: Epidemics in ant societies on a chip publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria status: public supervisor: - first_name: Sylvia full_name: Cremer, Sylvia id: 2F64EC8C-F248-11E8-B48F-1D18A9856A87 last_name: Cremer orcid: 0000-0002-2193-3868 title: Pathogen-mediated sexual selection and immunization in ant colonies type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2022' ... --- _id: '6435' abstract: - lang: eng text: "Social insect colonies tend to have numerous members which function together like a single organism in such harmony that the term ``super-organism'' is often used. In this analogy the reproductive caste is analogous to the primordial germ\r\ncells of a metazoan, while the sterile worker caste corresponds to somatic cells. The worker castes, like tissues, are\r\nin charge of all functions of a living being, besides reproduction. The establishment of new super-organismal units\r\n(i.e. new colonies) is accomplished by the co-dependent castes. The term oftentimes goes beyond a metaphor. We invoke it when we speak about the metabolic rate, thermoregulation, nutrient regulation and gas exchange of a social insect colony. Furthermore, we assert that the super-organism has an immune system, and benefits from ``social immunity''.\r\n\r\nSocial immunity was first summoned by evolutionary biologists to resolve the apparent discrepancy between the expected high frequency of disease outbreak amongst numerous, closely related tightly-interacting hosts, living in stable and microbially-rich environments, against the exceptionally scarce epidemic accounts in natural populations. Social\r\nimmunity comprises a multi-layer assembly of behaviours which have evolved to effectively keep the pathogenic enemies of a colony at bay. The field of social immunity has drawn interest, as it becomes increasingly urgent to stop\r\nthe collapse of pollinator species and curb the growth of invasive pests. In the past decade, several mechanisms of\r\nsocial immune responses have been dissected, but many more questions remain open.\r\n\r\nI present my work in two experimental chapters. In the first, I use invasive garden ants (*Lasius neglectus*) to study how pathogen load and its distribution among nestmates affect the grooming response of the group. Any given group of ants will carry out the same total grooming work, but will direct their grooming effort towards individuals\r\ncarrying a relatively higher spore load. Contrary to expectation, the highest risk of transmission does not stem from grooming highly contaminated ants, but instead, we suggest that the grooming response likely minimizes spore loss to the environment, reducing contamination from inadvertent pickup from the substrate.\r\n\r\nThe second is a comparative developmental approach. I follow black garden ant queens (*Lasius niger*) and their colonies from mating flight, through hibernation for a year. Colonies which grow fast from the start, have a lower chance of survival through hibernation, and those which survive grow at a lower pace later. This is true for colonies of naive\r\nand challenged queens. Early pathogen exposure of the queens changes colony dynamics in an unexpected way: colonies from exposed queens are more likely to grow slowly and recover in numbers only after they survive hibernation.\r\n\r\nIn addition to the two experimental chapters, this thesis includes a co-authored published review on organisational\r\nimmunity, where we enlist the experimental evidence and theoretical framework on which this hypothesis is built,\r\nidentify the caveats and underline how the field is ripe to overcome them. In a final chapter, I describe my part in\r\ntwo collaborative efforts, one to develop an image-based tracker, and the second to develop a classifier for ant\r\nbehaviour." acknowledged_ssus: - _id: Bio - _id: ScienComp - _id: M-Shop - _id: LifeSc alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Barbara E full_name: Casillas Perez, Barbara E id: 351ED2AA-F248-11E8-B48F-1D18A9856A87 last_name: Casillas Perez citation: ama: Casillas Perez BE. Collective defenses of garden ants against a fungal pathogen. 2019. doi:10.15479/AT:ISTA:6435 apa: Casillas Perez, B. E. (2019). Collective defenses of garden ants against a fungal pathogen. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:6435 chicago: Casillas Perez, Barbara E. “Collective Defenses of Garden Ants against a Fungal Pathogen.” Institute of Science and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6435. ieee: B. E. Casillas Perez, “Collective defenses of garden ants against a fungal pathogen,” Institute of Science and Technology Austria, 2019. ista: Casillas Perez BE. 2019. Collective defenses of garden ants against a fungal pathogen. Institute of Science and Technology Austria. mla: Casillas Perez, Barbara E. Collective Defenses of Garden Ants against a Fungal Pathogen. Institute of Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6435. short: B.E. Casillas Perez, Collective Defenses of Garden Ants against a Fungal Pathogen, Institute of Science and Technology Austria, 2019. date_created: 2019-05-13T08:58:35Z date_published: 2019-05-07T00:00:00Z date_updated: 2023-09-07T12:57:04Z day: '07' ddc: - '570' - '006' - '578' - '592' degree_awarded: PhD department: - _id: SyCr doi: 10.15479/AT:ISTA:6435 ec_funded: 1 file: - access_level: open_access checksum: 6daf2d2086111aa8fd3fbc919a3e2833 content_type: application/pdf creator: casillas date_created: 2019-05-13T09:16:20Z date_updated: 2021-02-11T11:17:15Z embargo: 2020-05-08 file_id: '6438' file_name: tesisDoctoradoBC.pdf file_size: 3895187 relation: main_file - access_level: closed checksum: 3d221aaff7559a7060230a1ff610594f content_type: application/zip creator: casillas date_created: 2019-05-13T09:16:20Z date_updated: 2020-07-14T12:47:30Z embargo_to: open_access file_id: '6439' file_name: tesisDoctoradoBC.zip file_size: 7365118 relation: source_file file_date_updated: 2021-02-11T11:17:15Z has_accepted_license: '1' keyword: - Social Immunity - Sanitary care - Social Insects - Organisational Immunity - Colony development - Multi-target tracking language: - iso: eng month: '05' oa: 1 oa_version: Published Version page: '183' project: - _id: 2649B4DE-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '771402' name: Epidemics in ant societies on a chip publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '1999' relation: part_of_dissertation status: public status: public supervisor: - first_name: Sylvia M full_name: Cremer, Sylvia M id: 2F64EC8C-F248-11E8-B48F-1D18A9856A87 last_name: Cremer orcid: 0000-0002-2193-3868 title: Collective defenses of garden ants against a fungal pathogen type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2019' ... --- _id: '819' abstract: - lang: eng text: 'Contagious diseases must transmit from infectious to susceptible hosts in order to reproduce. Whilst vectored pathogens can rely on intermediaries to find new hosts for them, many infectious pathogens require close contact or direct interaction between hosts for transmission. Hence, this means that conspecifics are often the main source of infection for most animals and so, in theory, animals should avoid conspecifics to reduce their risk of infection. Of course, in reality animals must interact with one another, as a bare minimum, to mate. However, being social provides many additional benefits and group living has become a taxonomically diverse and widespread trait. How then do social animals overcome the issue of increased disease? Over the last few decades, the social insects (ants, termites and some bees and wasps) have become a model system for studying disease in social animals. On paper, a social insect colony should be particularly susceptible to disease, given that they often contain thousands of potential hosts that are closely related and frequently interact, as well as exhibiting stable environmental conditions that encourage microbial growth. Yet, disease outbreaks appear to be rare and attempts to eradicate pest species using pathogens have failed time and again. Evolutionary biologists investigating this observation have discovered that the reduced disease susceptibility in social insects is, in part, due to collectively performed disease defences of the workers. These defences act like a “social immune system” for the colony, resulting in a per capita decrease in disease, termed social immunity. Our understanding of social immunity, and its importance in relation to the immunological defences of each insect, continues to grow, but there remain many open questions. In this thesis I have studied disease defence in garden ants. In the first data chapter, I use the invasive garden ant, Lasius neglectus, to investigate how colonies mitigate lethal infections and prevent them from spreading systemically. I find that ants have evolved ‘destructive disinfection’ – a behaviour that uses endogenously produced acidic poison to kill diseased brood and to prevent the pathogen from replicating. In the second experimental chapter, I continue to study the use of poison in invasive garden ant colonies, finding that it is sprayed prophylactically within the nest. However, this spraying has negative effects on developing pupae when they have had their cocoons artificially removed. Hence, I suggest that acidic nest sanitation may be maintaining larval cocoon spinning in this species. In the next experimental chapter, I investigated how colony founding black garden ant queens (Lasius niger) prevent disease when a co-foundress dies. I show that ant queens prophylactically perform undertaking behaviours, similar to those performed by the workers in mature nests. When a co-foundress was infected, these undertaking behaviours improved the survival of the healthy queen. In the final data chapter, I explored how immunocompetence (measured as antifungal activity) changes as incipient black garden ant colonies grow and mature, from the solitary queen phase to colonies with several hundred workers. Queen and worker antifungal activity varied throughout this time period, but despite social immunity, did not decrease as colonies matured. In addition to the above data chapters, this thesis includes two co-authored reviews. In the first, we examine the state of the art in the field of social immunity and how it might develop in the future. In the second, we identify several challenges and open questions in the study of disease defence in animals. We highlight how social insects offer a unique model to tackle some of these problems, as disease defence can be studied from the cell to the society. ' acknowledgement: "ERC FP7 programme (grant agreement no. 240371)\r\nI have been supremely spoilt to work in a lab with such good resources and I must thank the wonderful Cremer group technicians, Anna, Barbara, Eva and Florian, for all of their help and keeping the lab up and running. You guys will probably be the most missed once I realise just how much work you have been saving me! For the same reason, I must say a big Dzi ę kuj ę Ci to Wonder Woman Wanda, for her tireless efforts feeding my colonies and cranking out thousands of petri dishes and sugar tubes. Again, you will be sorely missed now that I will have to take this task on myself. Of course, I will be eternally indebted to Prof. Sylvia Cremer for taking me under her wing and being a constant source of guidance and inspiration. You have given me the perfect balance of independence and supervision. I cannot thank you enough for creating such a great working environment and allowing me the freedom to follow my own research questions. I have had so many exceptional opportunities – attending and presenting at conferences all over the world, inviting me to write the ARE with you, going to workshops in Panama and Switzerland, and even organising our own PhD course – that I often think I must have had the best PhD in the world. You have taught me so much and made me a scientist. I sincerely hope we get the chance to work together again in the future. Thank you for everything. I must also thank my PhD Committee, Daria Siekhaus and Jacobus “Koos” Boomsma, for being very supportive throughout the duration of my PhD. " alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Christopher full_name: Pull, Christopher id: 3C7F4840-F248-11E8-B48F-1D18A9856A87 last_name: Pull orcid: 0000-0003-1122-3982 citation: ama: Pull C. Disease defence in garden ants. 2017. doi:10.15479/AT:ISTA:th_861 apa: Pull, C. (2017). Disease defence in garden ants. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_861 chicago: Pull, Christopher. “Disease Defence in Garden Ants.” Institute of Science and Technology Austria, 2017. https://doi.org/10.15479/AT:ISTA:th_861. ieee: C. Pull, “Disease defence in garden ants,” Institute of Science and Technology Austria, 2017. ista: Pull C. 2017. Disease defence in garden ants. Institute of Science and Technology Austria. mla: Pull, Christopher. Disease Defence in Garden Ants. Institute of Science and Technology Austria, 2017, doi:10.15479/AT:ISTA:th_861. short: C. Pull, Disease Defence in Garden Ants, Institute of Science and Technology Austria, 2017. date_created: 2018-12-11T11:48:40Z date_published: 2017-09-26T00:00:00Z date_updated: 2023-09-28T11:31:32Z day: '26' ddc: - '576' - '577' - '578' - '579' - '590' - '592' degree_awarded: PhD department: - _id: SyCr doi: 10.15479/AT:ISTA:th_861 file: - access_level: closed checksum: 4993cdd5382295758ecc3ecbd2a9aaff content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: dernst date_created: 2019-04-05T07:53:04Z date_updated: 2020-07-14T12:48:09Z file_id: '6199' file_name: 2017_Thesis_Pull.docx file_size: 18580400 relation: source_file - access_level: open_access checksum: ee2e3ebb5b53c154c866f5b052b25153 content_type: application/pdf creator: dernst date_created: 2019-04-05T07:53:04Z date_updated: 2020-07-14T12:48:09Z file_id: '6200' file_name: 2017_Thesis_Pull.pdf file_size: 14400681 relation: main_file file_date_updated: 2020-07-14T12:48:09Z has_accepted_license: '1' language: - iso: eng license: https://creativecommons.org/licenses/by/4.0/ month: '09' oa: 1 oa_version: Published Version page: '122' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria publist_id: '6830' pubrep_id: '861' related_material: record: - id: '616' relation: part_of_dissertation status: public - id: '806' relation: part_of_dissertation status: public - id: '734' relation: part_of_dissertation status: public - id: '732' relation: part_of_dissertation status: public status: public supervisor: - first_name: Sylvia M full_name: Cremer, Sylvia M id: 2F64EC8C-F248-11E8-B48F-1D18A9856A87 last_name: Cremer orcid: 0000-0002-2193-3868 title: Disease defence in garden ants tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2017' ... --- _id: '1404' abstract: - lang: eng text: "The co-evolution of hosts and pathogens is characterized by continuous adaptations of both parties. Pathogens of social insects need to adapt towards disease defences at two levels: 1) individual immunity of each colony member consisting of behavioural defence strategies as well as humoral and cellular immune responses and 2) social immunity that is collectively performed by all group members comprising behavioural, physiological and organisational defence strategies.\r\n\r\nTo disentangle the selection pressure on pathogens by the collective versus individual level of disease defence in social insects, we performed an evolution experiment using the Argentine Ant, Linepithema humile, as a host and a mixture of the general insect pathogenic fungus Metarhizium spp. (6 strains) as a pathogen. We allowed pathogen evolution over 10 serial host passages to two different evolution host treatments: (1) only individual host immunity in a single host treatment, and (2) simultaneously acting individual and social immunity in a social host treatment, in which an exposed ant was accompanied by two untreated nestmates.\r\n\r\nBefore starting the pathogen evolution experiment, the 6 Metarhizium spp. strains were characterised concerning conidiospore size killing rates in singly and socially reared ants, their competitiveness under coinfecting conditions and their influence on ant behaviour. We analysed how the ancestral atrain mixture changed in conidiospere size, killing rate and strain composition dependent on host treatment (single or social hosts) during 10 passages and found that killing rate and conidiospere size of the pathogen increased under both evolution regimes, but different depending on host treatment.\r\n\r\nTesting the evolved strain mixtures that evolved under either the single or social host treatment under both single and social current rearing conditions in a full factorial design experiment revealed that the additional collective defences in insect societies add new selection pressure for their coevolving pathogens that compromise their ability to adapt to its host at the group level. To our knowledge, this is the first study directly measuring the influence of social immunity on pathogen evolution." acknowledgement: This work was funded by the DFG and the ERC. alternative_title: - IST Austria Thesis author: - first_name: Miriam full_name: Stock, Miriam id: 42462816-F248-11E8-B48F-1D18A9856A87 last_name: Stock citation: ama: Stock M. Evolution of a fungal pathogen towards individual versus social immunity in ants. 2014. apa: Stock, M. (2014). Evolution of a fungal pathogen towards individual versus social immunity in ants. IST Austria. chicago: Stock, Miriam. “Evolution of a Fungal Pathogen towards Individual versus Social Immunity in Ants.” IST Austria, 2014. ieee: M. Stock, “Evolution of a fungal pathogen towards individual versus social immunity in ants,” IST Austria, 2014. ista: Stock M. 2014. Evolution of a fungal pathogen towards individual versus social immunity in ants. IST Austria. mla: Stock, Miriam. Evolution of a Fungal Pathogen towards Individual versus Social Immunity in Ants. IST Austria, 2014. short: M. Stock, Evolution of a Fungal Pathogen towards Individual versus Social Immunity in Ants, IST Austria, 2014. date_created: 2018-12-11T11:51:49Z date_published: 2014-04-01T00:00:00Z date_updated: 2021-01-12T06:50:30Z day: '01' department: - _id: SyCr language: - iso: eng month: '04' oa_version: None page: '101' publication_status: published publisher: IST Austria publist_id: '5803' status: public supervisor: - first_name: Sylvia M full_name: Cremer, Sylvia M id: 2F64EC8C-F248-11E8-B48F-1D18A9856A87 last_name: Cremer orcid: 0000-0002-2193-3868 title: Evolution of a fungal pathogen towards individual versus social immunity in ants type: dissertation user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2014' ... --- _id: '1395' abstract: - lang: eng text: In this thesis I studied various individual and social immune defences employed by the invasive garden ant Lasius neglectus mostly against entomopathogenic fungi. The first two chapters of this thesis address the phenomenon of 'social immunisation'. Social immunisation, that is the immunological protection of group members due to social contact to a pathogen-exposed nestmate, has been described in various social insect species against different types of pathogens. However, in the case of entomopathogenic fungi it has, so far, only been demonstrated that social immunisation exists at all. Its underlying mechanisms r any other properties were, however, unknown. In the first chapter of this thesis I identified the mechanistic basis of social immunisation in L. neglectus against the entomopathogenous fungus Metarhizium. I could show that nestmates of a pathogen-exposed individual contract low-level infections due to social interactions. These low-level infections are, however, non-lethal and cause an active stimulation of the immune system, which protects the nestmates upon subsequent pathogen encounters. In the second chapter of this thesis I investigated the specificity and colony level effects of social immunisation. I demonstrated that the protection conferred by social immunisation is highly specific, protecting ants only against the same pathogen strain. In addition, depending on the respective context, social immunisation may even cause fitness costs. I further showed that social immunisation crucially affects sanitary behaviour and disease dynamics within ant groups. In the third chapter of this thesis I studied the effects of the ectosymbiotic fungus Laboulbenia formicarum on its host L. neglectus. Although Laboulbeniales are the largest order of insect-parasitic fungi, research concerning host fitness consequence is sparse. I showed that highly Laboulbenia-infected ants sustain fitness costs under resource limitation, however, gain fitness benefits when exposed to an entomopathogenus fungus. These effects are probably cause by a prophylactic upregulation of behavioural as well as physiological immune defences in highly infected ants. alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Matthias full_name: Konrad, Matthias id: 46528076-F248-11E8-B48F-1D18A9856A87 last_name: Konrad citation: ama: 'Konrad M. Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus. 2014.' apa: 'Konrad, M. (2014). Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus. Institute of Science and Technology Austria.' chicago: 'Konrad, Matthias. “Immune Defences in Ants: Effects of Social Immunisation and a Fungal Ectosymbiont in the Ant Lasius Neglectus.” Institute of Science and Technology Austria, 2014.' ieee: 'M. Konrad, “Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus,” Institute of Science and Technology Austria, 2014.' ista: 'Konrad M. 2014. Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus. Institute of Science and Technology Austria.' mla: 'Konrad, Matthias. Immune Defences in Ants: Effects of Social Immunisation and a Fungal Ectosymbiont in the Ant Lasius Neglectus. Institute of Science and Technology Austria, 2014.' short: 'M. Konrad, Immune Defences in Ants: Effects of Social Immunisation and a Fungal Ectosymbiont in the Ant Lasius Neglectus, Institute of Science and Technology Austria, 2014.' date_created: 2018-12-11T11:51:46Z date_published: 2014-02-01T00:00:00Z date_updated: 2023-09-07T11:38:56Z day: '01' degree_awarded: PhD department: - _id: SyCr language: - iso: eng month: '02' oa_version: None page: '131' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria publist_id: '5814' status: public supervisor: - first_name: Sylvia M full_name: Cremer, Sylvia M id: 2F64EC8C-F248-11E8-B48F-1D18A9856A87 last_name: Cremer orcid: 0000-0002-2193-3868 title: 'Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus' type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2014' ...