Paling in Comparison: The Role of Sex and Temperature in Melanin-Based Immune Function
2017-10
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
Paling in Comparison: The Role of Sex and Temperature in Melanin-Based Immune Function
Authors
Published Date
2017-10
Publisher
Type
Thesis or Dissertation
Abstract
Sex differences in disease susceptibility have been observed across a wide range of species, yet we lack a strong understanding of how environmental context influences these patterns. In this thesis, I take a life-history approach to investigating the plasticity of immunological sex differences in insects. Insects rely on the pigment melanin for both immune function and the structure and coloration of the cuticle (i.e. integument). Although many studies have shown evidence of correlations between immunity and cuticle pigmentation, most do not take into account the many potential modes of selection acting on cuticle melanism. Given that the biochemical precursors of melanin are a common currency in thermoregulation, sexual ornamentation, and immune function in insects, we hypothesized that sex differences in melanin-based resource allocation contribute to sex differences in immunity, and that the thermal environment will moderate this influence. My thesis work focused on the interactive effects of sexual selection and thermal selection on cuticle melanism and immunity in the Pacific field cricket (Teleogryllus oceanicus). After rearing crickets under multiple temperatures, we found, as predicted, that females invested more in immunity, males invested more in cuticle melanism, and both immune function and cuticle melanism were reduced in individuals that developed under warmer temperatures. Our results suggest that sex-specific investment in melanin corresponds with sex differences in immunity and that thermoregulation may act as an immune constraint under high temperatures, thus regulating the extent to which males and females diverge in disease susceptibility. By quantifying melanin-based traits underlying strategies for both reproduction and survival in insects, this study sheds light onto the selective forces shaping sex differences in immunity and insect life-history in general.
Description
University of Minnesota M.S. thesis.October 2017. Major: Ecology, Evolution and Behavior. Advisor: Marlene Zuk. 1 computer file (PDF); 51 pages.
Related to
Replaces
License
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Ehrlich, Rebecca. (2017). Paling in Comparison: The Role of Sex and Temperature in Melanin-Based Immune Function. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/192645.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.