PHYLOGENETIC ANALYSIS OF PARTIAL CAPSID PROTEIN GENE OF RABBIT HAEMORRHAGIC DISEASE VIRUS (RHDV) STRAINS ISOLATED BETWEEN 1993 AND 2005 IN POLAND

Abstract

The 18 RHDV strains, isolated between 1993 and 2005 in Poland, as well as one standard strain were used in these studies. The RT-PCR technique was carried out in order to amplify the 538 bp fragment located in the variable region of gene encoding capsid protein (VP60). The phylogenetic analysis of nucleotide sequences of 18 Polish and 25 foreign strains revealed that Polish strains were clustered to 4 genogroups. One of them from 1993 was grouped together with old European strains isolated between 1987 and 1990. Thirteen strains isolated between 1994 and 2004, as well as two strains isolated in 1994 and 1996, were clustered to two separate genetic groups. Two strains detected in 2004 and 2005, were located in genogroup of antigenic variants. The maximum nucleotide divergence among Polish strains (10.3%) was found between strain isolated in 1996 and antigenic variants. The alignment of deduced amino acid sequences of the VP60 confirmed the localisation of 2 Polish strains in genetic group of antigenic variants. The identical amino acid substitutions in the same positions, like in other antigenic variants, were observed. The relation between antigenic properties and genetic variations of strains was taken under consideration.