Date of Award
Few studies have explored the evolutionary mechanisms that maintain adaptive immunogenetic diversity in nature. We took advantage of museum samples to test for evidence of parasite-mediated fluctuating selection at MHC Class II-ß loci in an endemic island reptile. The Saban anole Anolis sabanus is commonly infected with three species of malaria (Plasmodium). Proportions of each parasite species detected in anole blood samples fluctuated over space and time, suggesting competitive interactions between parasites or differences in vector ecology. Our analyses of parasite prevalence and MHC Class II-ß allelic variation found that malaria infection was not associated with patterns of host immunogenetic diversity. We found that infection was contingent on sex, with males being more likely to test positive for malaria. These results indicate that malaria parasites do not impose significant selective pressures on A. sabanus or that genetic drift in this island population overwhelms the effects of parasite-mediated selection.
Zwicky, Gina, "Fluctuating Parasite Prevalence Is Not Linked to Patterns of MHC Class II-ß Diversity in an Island Endemic Reptile" (2022). University of New Orleans Theses and Dissertations. 2985.