Partial cloning of the genome of an unusual shrimp parvovirus (HPV):use of gene probes in disease diagnosis

Abstract

The DNA genome of the hepatopancreatic parvovirus (HPV) of penaeid s h n m p was partially cloned The largest insert obtained, from the clone OF44, was 2 3 k b p In size and characterized by mapping w ~t h restnction enzymes It was used to construct 2 different DIG-11 dUTP labelled probes, which appeared specific to the virus, without any cross-reactivity w ~t h uninfected tissues or with a second s h n m p parvovirus, infectious hypodermal and haematopoietlc necrosis virus (IHHNV) In sltu hybridization on paraffin sections of the hepatopancreas of infected and uninfected shrimp showed the probes react with Infected tlssue and not with umnfected tissue In positive hepatopancreas, the probes produced a strong labelling of infected nuclei, especially of the nucleolus and the karyoplasm peripheric to the intranuclear inclusion body Intranuclear inclusion bodies, which are the principal diagnostic feature of HPV infections by histology, also reacted with the probes, but less intensely In heavily infected hepatopancreas, cell d e b r ~s reacted strongly wlth the probes, as did the microvilli on the surface of eplthelial cells KEY WORDS: HPV .