The bovine herpesvirus 1 (BHV-1) US4 gene encodes glycoprotein G (gG), whic
h is conserved in the majority of alphaherpesviruses. In order to identify
the role of BHV-1 gG in the viral infection cycle, a gG minus BHV-1 mutant
and its gG-positive revertant were constructed and their growth characteris
tics in Madin-Darby bovine kidney (MDBK) cells were compared. The gG minus
mutant formed smaller plaques than the gG-positive BHV-1 in MDBK cells. Whe
n a monolayer culture of MDBK cells was infected with BHV-1 at a low multip
licity of infection and overlaid with semi-solid growth medium, under which
adsorption of the mature virion released in the medium was inhibited, gG-p
ositive BHV-1 multiplied, while the growth of the ge negative BHV-1 was sev
erely inhibited. These data suggest that BHV-1 gG functions in direct cell-
to-cell transmission mechanism of BHV-1 in tissue culture. (C) 2000 Elsevie
r Science B.V. All rights reserved.