Ecology and Evolutionary Biology Commons^™

Effects Of 11-Kt And Prolactin On Gene Expression, Parental Care Behaviour And Immune Response In Male Bluegill Sunfish., Adriano A P Da Cunha

Electronic Thesis and Dissertation Repository

Parental care is very critical for reproduction in species that provide it. Hormones such as prolactin and androgens play a crucial role in parenting and reproductive behaviours. In mammals and birds, prolactin’s role in parental care is well-established; it stimulates milk production and stimulates attachment to newborns by its release in the preoptic area of the hypothalamus (POA), among other functions. Androgens, on the other hand, are commonly associated with male secondary sex characteristics, territoriality, and aggressiveness in mammals and birds. There are similar reports of prolactin and androgen effects in fish, but there are fewer studies. I investigated if …

Hitchhiker's Guide To Migration: Effects Of Experimental Parasitic Infection And Other Immune Challenges On Migratory Traits Of Sparrows, Tosha R. Kelly

Electronic Thesis and Dissertation Repository

Seasonal migration exposes animals to a variety of habitats and parasites, and if infected migratory birds migrate successfully there is great potential for birds to transport infectious diseases long distances. Our current understanding of whether birds contribute to the spread of disease relies upon observational field studies that are limited in their ability to discern cause from effect. Using captive and field-based experiments for my doctoral research, I answered three research questions: (1) are nocturnal migratory restlessness (Zugunruhe) and body condition affected by mounting an acute phase immune response during migration; (2) what are the impacts of parasitic …

The Major Histocompatibility Complex In Song Sparrows: Immunity, Signals, And Mate Choice, Joel W.G. Slade

Electronic Thesis and Dissertation Repository

In recent years, sexual selection theory has redefined genetic quality to consider not only additive genetic effects on fitness but also non-additive genetic effects, such as heterozygote advantage or disadvantage. In jawed vertebrates, the major histocompatibility complex (MHC) gene family has been shown to exhibit both additive and non-additive genetic effects on fitness. MHC gene products are involved in initiating adaptive immune responses, and MHC genotype determines the range of pathogens to which an individual can respond. Therefore, parasite-mediated selection at MHC may favour locally-adapted, rare, or particular combination of alleles. Because heterozygote advantage at MHC is widespread, sexual selection …

Mhc Class Iiβ Diversity As A Correlate Of Neutral-Locus Similarity And Diversity, And A Predictor Of Overwinter Return, In Song Sparrows (Melospiza Melodia), Matthew J. Watson

Electronic Thesis and Dissertation Repository

Abstract

The major histocompatibility complex (MHC) is a family of genes involved with recognizing pathogens and mounting an immune response. Parasite-mediated selection often favours heterozygosity at MHC because MHC-diverse individuals recognize a wider range of pathogens. Because migratory birds encounter many pathogens, I hypothesized that MHC diversity predicts overwinter and juvenile survivorship in song sparrows (Melospiza melodia). I found no correlation between MHC diversity and neutral-locus (microsatellite) heterozygosity, suggesting that measures of neutral and adaptive genetic diversity provide complementary rather than redundant information. However, pairwise similarity at MHC predicted pairwise similarity at microsatellite loci. In contrast to my hypothesis, MHC …

A Test Of The Effects Of Androgens On Immunity: No Relationship Between 11-Keto Testosterone And Immune Performance In Bluegill Sunfish (Lepomis Macrochirus), John W. Loggie

Electronic Thesis and Dissertation Repository

The posited immunosuppressive effects of androgens are a key component of the immunocompetence handicap hypothesis (ICHH). My thesis uses bluegill sunfish (Lepomis macrochirus) to test two predictions arising from this hypothesis: (1) natural concentrations of the androgen 11-keto testosterone (11-KT) will be negatively related with immunity, and (2) an immunochallenge will lower 11-KT concentration. I found no evidence for a relationship between natural 11-KT concentration and measures of immunity (leukocyte counts, respiratory burst, cytokine gene expression), and an immunochallenge with Vibrio vaccine did not affect 11-KT concentration. I performed a meta-analysis of immunochallenge studies to help interpret my …