DNA from dust: comparative genomics of large DNA viruses in field surveillance samples

Mareks disease (MD) is a lymphoproliferative disease of chickens caused by airborne gallid herpesvirus type 2 (GaHV-2, aka MDV-1). Mature virions are formed in the feather follicle epithelium cells of infected chickens from which the virus is shed as fine particles of skin and feather debris, or poultry dust. Poultry dust is the major source of virus transmission between birds in agricultural settings. Despite both clinical and laboratory data that show increased virulence in field isolates of MDV-1 over the last 40 years, we do not yet understand the genetic basis of MDV-1 pathogenicity. Our present knowledge on genome-wide variation in the MDV-1 genome comes exclusively from laboratory-gro