MAREK'S DISEASE (MD) IS A HIGHLY CONTAGIOUS VIRAL DISEASE OF CHICKENS, WHICH IS OF SIGNIFICANT IMPORTANCE TO THE POULTRY INDUSTRY, ACCOUNTING FOR AN ESTIMATED ECONOMIC WORLDWIDE LOSS OF $1-2 BILLION DOLLARS EVERY YEAR. THE VIRUS THAT CAUSES MD IS CALLED MAREK'S DISEASE VIRUS (MDV). MDV CAUSES TUMORS IN INFECTED BIRDS. AFTER INFECTING CELLS, THE MDV GENOME (DNA) IS SOMETIMES INSERTED INTO THE GENOME (DNA) OF THE HOST CHICKEN CELL. THIS JOINING PROCESS IS CALLED VIRAL INTEGRATION. WHAT ARE THE EFFECTS ON THE CELLS OF THE INFECTED BIRD WHEN MDV INTEGRATES? SCIENTISTS KNOW THAT INTEGRATION IS NECESSARY FOR THE VIRUS TO CAUSE TUMORS BUT WHAT EXACTLY HAPPENS FOLLOWING INTEGRATION THAT LEADS TO TUMORS IS UNCLEAR. ONE UNDER-EXPLORED CONSEQUENCE OF MDV INTEGRATION IS EFFECTS ON THE STRUCTURE OF THE INFECTED CELL'S CHROMOSOMES. THIS IS WHAT WE WILL EXAMINE IN OUR STUDIES. WE WILL MAINLY USE LABORATORY TECHNIQUES BASED ON A PROCEDURE CALLED HI-C (PRONOUNCED HIGH "C"). WE WILL LOOK ATTHE ORGANIZATION, ARRANGEMENT, AND CONTACT POINTS AMONG THE CHICKEN CHROMOSOMES IN MDV TUMOR CELLS AND COMPARE THEM TO THE STRUCTURE OF CHROMOSOMES PRESENT IN NORMAL UNINFECTED CHICKEN CELLS. OUR STUDIES WILL ALSO DETERMINE WHICH CHICKEN GENES MAY BE AFFECTED IN THE TUMORS; INDIVIDUAL GENE EXPRESSION LEVELS IN TUMORS COULD BE INCREASED, DECREASED, OR UNCHANGED. THESE COMPARISONS SHOULD ALLOW US TO CATALOG THE CHANGES THAT OCCUR IN MD TUMORS AND THAT COULD POSSIBLY CONTRIBUTE TO TUMOR FORMATION.