---
OA_place: publisher
_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:<a href="https://doi.org/10.15479/AT:ISTA:10727">10.15479/AT:ISTA:10727</a>
  apa: Metzler, S. (2022). <i>Pathogen-mediated sexual selection and immunization
    in ant colonies</i>. Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/AT:ISTA:10727">https://doi.org/10.15479/AT:ISTA:10727</a>
  chicago: Metzler, Sina. “Pathogen-Mediated Sexual Selection and Immunization in
    Ant Colonies.” Institute of Science and Technology Austria, 2022. <a href="https://doi.org/10.15479/AT:ISTA:10727">https://doi.org/10.15479/AT:ISTA:10727</a>.
  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. <i>Pathogen-Mediated Sexual Selection and Immunization in Ant
    Colonies</i>. Institute of Science and Technology Austria, 2022, doi:<a href="https://doi.org/10.15479/AT:ISTA:10727">10.15479/AT:ISTA:10727</a>.
  short: S. Metzler, Pathogen-Mediated Sexual Selection and Immunization in Ant Colonies,
    Institute of Science and Technology Austria, 2022.
corr_author: '1'
date_created: 2022-02-04T15:45:12Z
date_published: 2022-02-07T00:00:00Z
date_updated: 2026-04-07T14:30:18Z
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
fulldoi: https://doi.org/10.15479/AT:ISTA:10727
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: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2022'
...