The researchers have designed tests to explore how the gene functions. Parcells found that the GFP is turned off in tumors and cells made from a tumor. But the virus glows green when it begins to replicate itself. Parcell's research includes a project to find changes in MDV that may require new vaccines. Typically, it showed up only in younger birds whose immune systems were not fully developed.
Viruses invade host cells by binding to receptors on the surface of the cells.
If MDV is invading cells it used to ignore, something on the surface of the virus is likely to have changed. Sooner or later, such changes will render current vaccines ineffective. Parcells' research may lead to the development of new vaccines or other methods for controlling losses due to Marek's disease. Fred Miller of agricultural publications contributed to this story.