2006 Annual Report 4d.Progress report. This report serves to document research conducted under a Master Memorandum of Understanding (MOU) between ARS and Michigan State University. Full progress reports and additional details of research can be found in the report for the parent project (3635-32000-013-00D entitled "Epidemiology, Diagnosis and Control of Retrovirus Infection in Poultry"). This Master MOU covers research conducted in collaboration with Department of Pathobiology and Diagnostic Investigation. One graduate student from this department was assigned to our research unit to conduct research aimed at the molecular and biological characterization of naturally occurring ALV,ALV-B/J.