Sequencing genetic diversity in host and parasite genes using the ultra-high throughput 454 GS-Flex platform

Hosts and parasites are believed to be in a continual arms race as each species tries to adapt to the other; parasites try to infect hosts while hosts try to resist being infected. This arms race has been played out for millions of years and there is a long-standing prediction in evolutionary biology that those genes in hosts and parasites most directly involved in the interaction will show high levels of genetic diversity within a species, and genetic divergence between species. We are now in a position to test this prediction. Partly because we now have a much better understanding of which genes are particularly involved in host-parasite interactions. Partly because a new technology has emerged to sequence thousands of genes simultaneously. What we will do here is to link microarray results, which assay the expression of thousands of genes responding to infection in both hosts and parasites, to the genetic diversity in these genes. Our hypothesis is that the genes in hosts responding to infection, and the genes in parasites responding to host immunity, will show the highest level of polymorphism, and the highest divergence between species. We can also investigate such effects further by grouping genes according to their function or pattern of gene expression. This proposal will provide additional sequencing costs to supplement an existing consortium, funded by NERC, which is addressing these questions in nematode infections of red grouse, Soay sheep and laboratory rats. As such it provides excellent value for money since it builds on existing ressults and manpower.