The construction is described of a molecular probe to P virus, a double str
anded RNA virus belonging to the Reoviridiae, which is an endemic pathogen
of swimming crabs in British coastal waters and the Mediterranean. The prob
e hybridises to the P virus genome and can be easily produced in large quan
tities by PCR. It may be used by dot blotting or in situ hybridisation to s
pecifically detect P virus in tissues and cells of natural or experimentall
y infected animals. Analyses of tissue samples with this probe show that th
e virus infects connective tissues of gills and hepatopancreas. This is the
first gene probe to be constructed for a native viral pathogen of temperat
e water brachyurans and it will be useful to study virus ecology and virus-
host interactions in vivo and in vitro. An understanding of these processes
is essential to control and manage disease and, ultimately, to identify im
mune effecters capable of destroying viral pathogens. (C) 1999 Elsevier Sci
ence B.V. All rights reserved.