Marek's disease virus pathogenesis and disease resistance

This was a collaborative project in which a novel gene designed to block MDV replication in chicken cells was developed by collaborators. This specific part of the project involved production of genetically-modified chickens carrying this new gene and testing the response of these chickens to infection with MDV.

Marek's disease (MDV) is a major viral disease of commercial chickens. The virus is very robust and hard to clean from poultry housing. Vaccines are used to control infections with MDV but they are not fully protective and the strains of MDV are becoming more virulent. The aim of this project was to investigate a novel approach to control of MDV by using genetic modification to block infection in every chicken carrying a new gene.

Genetically modified chickens were generated that expressed the small RNA molecules that had been shown to affect MDV replication in a test system. We could not detect greater resistance to MDV infection in these birds. The project did demonstrate that small interfering RNA molecules can be introduced into chickens and the RNAs found in all tissues.