DETECTION OF VIRAL-RNA BY ELECTRON-MICROSCOPIC IN-SITU HYBRIDIZATION (ISH-EM) IN THE GERMINAL EPITHELIUM OF MICE INFECTED WITH ENCEPHALOMYOCARDITIS (EMC) VIRUS

Electron microscopic in situ hybridization (ISH-EM) was first applied to the detection of viral RNA in the germinal epithelium of mice inocu lated i.p. with 10(5) plaque-forming units/mouse of the D variant of e ncephalomyocarditis virus (EMC-D). Signals of viral RNA were first det ected in a small number of Sertoli cells showing mild degeneration at 2 days post inoculation, and 2 days later, they were also defected in germinal cells and spermatogonia when Sertoli cells showed prominent d egeneration. The results clearly demonstrated that the first site of v iral attack in the germinal epithelium was Sertoli cell in the case of EMC-D-induced mouse orchitis.