Browsing by Subject "moisture"

Life historyresearch seeks to explain how natural selection and ecological challenges shape organisms to optimize their fitness. A strong immune defense is energetically demanding to upkeep and there may be trade-offs among other life history traits. Investing a lot of energy to upkeep a strong immune defense in conditions where there are less pathogens and parasites might have negative fitness effects. Heliconius eratois a neotropical species of butterfly found widely in South America. The immune defense, ecologicalfactors affecting its immune defense, and possible life history trade-offs of the butterfly are currently not well known. Environmental moisture conditions have been shown to affect the diversity, quality and amount of microorganisms and parasites. The aim of this thesis was to use real-time quantitative PCR (RT-qPCR) to quantify immune gene expression of individuals of the butterfly species Heliconius eratocollected from different environmental moisture conditions. Additionally, individual variation in encapsulation rates, a physiological measure of immunity, was compared across the moisture gradient. Results indicate reduced expression of the gene encoding the antimicrobial peptide attacin in dry conditions, but no difference in encapsulation rates across the moisture gradient. Additionally, differential expression of the prophenoloxidase encoding gene was found between male and female butterflies. These results indicate a possibility of differential immune threats in different environmental moisture conditions in H. erato, but requires further study.