Research Fellows Directory
Dr Francis Jiggins
University of Cambridge
The survival of all animals relies on their ability to defend themselves against a variety of pathogenic viruses and micro-organisms. There are often large genetic differences between individuals of the same species in their ability to resist infection by these pathogens. This project aims to identify the genes that cause these differences. This will allow us to understand both the molecular reasons why some individuals are susceptible to infection, and the evolutionary reasons why natural selection hasn’t eliminated susceptibility genes from the population.
We have found that in the fruit flies, there is an ongoing arms race in which hosts evolve new defences and parasites evolve to overcome these defences. This means that within populations of hosts, old versions of genes that are susceptible to infection are continually being replaced by new resistant versions. However, the parasites tend to be ahead in this evolutionary battle. This is partly because parasites die when they encounter a resistant host, but hosts rarely encounter the parasites, and infection only makes them slightly sick. In other words parasite benefit more from infecting their hosts than the host benefits from being resistant.
We have also identified two new genes that make fruit flies resistant to viruses. These promise to give us new insights into what determines whether a virus can infect a cell, which may give us insights into how mosquitoes interact with the viruses they transmit to humans.
The lab is now extending this research to a mosquito that transmits human pathogens like dengue fever and yellow fever. The ultimate aim of this work will be to develop new strategies to control these deadly diseases.
Interests and expertise (Subject groups)