Studies on the molecular biological peculiarities of bovine herpesvirus 4

Studies on the molecular biological features of bovine herpesvirus 4 (BHV 4) strains isolated in Bulgaria have been conducted. Two types of polymerase chain reaction have been developed and applied to confirm the gB and TK genes. A restrictase fragment analysis was performed using various types of restrictase enzymes. The tested Bulgarian strains differed in their restrictase genomic profile from the reference European strain Movar 33/63 and from the American strain DN 599, and were clearly different each from the other. No clear relationship has been established between the restrictase enzyme profiles and the tropism of the isolated viruses. Sequencing of isolated ВHV 4 strains showed homo­logy with the reference European strain Movar 33/63. After construction of the phylogenetic tree, three ВHV 4 strains were at one branch of the phylogenetic tree, while two other strains were at the branch of reference Movar 33/63 strain. Applied molecular biology methods can be successfully used for differentiation and detailed genetic characterisation of the isolated BHV 4 strains.