Project Number: 3635-32000-016-09
Project Type: Trust

Start Date: Nov 01, 2012
End Date: Oct 31, 2014

Objective:
1) To characterize contemporary Marek's disease virus strains and correlate virulence with multiple other factors. 2) To sequence informative variable regions within the viral genome of these field strains to analyze the molecular epidemiology of these isolates.

Approach:
The primary goal of this study is to determine if MDV has increased in virulence compared to the last comprehensive set of MDV isolates that were solicited and pathotyped nearly 15 years ago. Objective 1 addresses this goal and will also examine if virulence has changed on farms in which isolates have been previously isolated, and whether strains are evolving differently in separate geographic locations or chicken lines. In Objective 2, we will take advantage of next generation sequencing (NGS) power to molecularly characterize samples collected from farms for pathotyping. Our primary goal will be to determine if polymorphisms in the MDV genome are associated with pathotype and other measured MD-associated traits. We will also determine if MDV sequences differ among isolates from the same bird, farm, geographic location, or over time in order to gain better understanding of the evolutionary trends of the virus. These methods will provide information on the diversity of MDV sequence variation and may lead to alternative methods of pathotyping.