Abstract
A monoclonal antibody (MAb) against the G-protein of yellow head virus (YHV) gave positive binding in functional lobes of the lymphoid organ (LO) at 24 h post YHV injection. Thereafter, the positive reaction progressed to newly formed LO spheroids or LOS (Type-A) and thence to preexisting LOS (Types B and C). Apoptotic cells in LO tubules gave positive MAb reactions while those in preexisting LOS gave negative. Gills, hepatopancreatic interstitial cells, midgut sub-epithelial cells, the heart, hematopoietic tissue, sub-cuticular epithelium, general connective tissue and muscle tissue also gave positive MAb reactions. Nerve tissue remained negative throughout the period of the test (50 h post injection). Tissues of the ovary and testis were negative until 36-hour post YHV injection by which time connective tissue and follicle cells became positive. Oocytes and sperm remained negative.