Previous Article | Next Article ![]()
J. Virol., Apr 1996, 2508-2515, Vol 70, No. 4
J Bergeron, B Hebert and P Tijssen
The Kresse strain of porcine parvovirus (PPV) was cloned into pUC19, and
independent infectious clones were sequenced. The PPV Kresse and NADL-2
strains, which have different pathogenicities, shared an identical genomic
organization and a high degree of sequence identity. Partial genomes (1.5
or 1.6 kb) of 15 field isolates were also amplified by PCR in regions with
significant sequence differences between the laboratory strains. Five amino
acid differences were consistently present within the VP1/VP2 coding region
of the Kresse strain and virulent field isolates. A number of inconsistent
point mutations were also found throughout the genomes of field isolates.
In addition, among those with the vaccine amino acid profile, all but one
isolate (IAF-3) contained a 127-bp noncoding direct repeat downstream of
the capsid protein gene. The one exception was also the only vaccine- type
PPV obtained from a mummified fetus. In order to identify genetic elements
responsible for the distinct tropism (and possibly the pathology) of the
Kresse strain, in vitro cell systems which differentiated the virulent from
the vaccinal strains were established. Subsequently, chimeric infectious
clones of the Kresse and NADL-2 strains were used to identify the
allotropic determinant located in the VP1/VP2 region. The transfer of the
BglII fragment of the Kresse genome, containing three amino acid
differences, into the NADL-2 background, or the opposite construct, caused
the phenotype of the target genome to revert to that of the parent strain
of the BglII fragment. Prediction of the localization of amino acid
differences on the basis of canine parvovirus capsid structure indicates
that each is located on or near the outer surface of the virion. In
particular, the position of one mutation (S-436-->P) maps by analogy to
the threefold spike, the most accessible region of the capsid.
Copyright © 1996, American Society for Microbiology
Genome organization of the Kresse strain of porcine parvovirus: identification of the allotropic determinant and comparison with those of NADL-2 and field isolates
Centre de Recherche en Virologie, Institut Armand-Frappier, Universite du Quebec, Laval, Canada.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|