Parasites are common throughout the natural world and most parasites spread by moving among individuals infectiously. Many insects, however, harbor microscopic parasites that are thought to be transmitted solely through the egg from mother to offspring. These microorganisms are termed reproductive parasites because they usually cause abnormalities during reproduction, such as feminization of males, killing of male embryos or development of embryos without fertilization. Most studies of reproductive parasites assume that transmission is strictly from mother to offspring. Surprisingly, recent experimental work has shown that these microorganisms can occasionally spread infectiously among unrelated individuals. The extent of infectious transmission in fruit flies (Drosophila) will be investigated by using DNA markers to detect transfer between individuals and between generations.
The research addresses fundamental process of disease and parasite transmission. Moreover, reproductive parasites such as those examined here have been proposed as biological control agents for some insect-vectored human diseases. If infectious transmission of the parasite is common, current models for pest control will need to be modified to prevent spread of the parasite to non-target insects. The investigators will continue to engage high school students and undergraduates in laboratory research and are developing outreach programs for high school and middle school students. This project is ideal for younger students because it is relatively simple conceptually, interesting (male-killing and feminization piques the interest of young students) and includes components that are technically simple.
