High-frequency intergenomic recombination plays a significant role in the evolution of suid herpesvirus 1 (Aujeszky's disease virus) : a review
Christensen, L.S.
Acta Veterinaria Hungarica 42(2-3): 179-182
1994
ISSN/ISBN: 0236-6290 PMID: 7810410 Document Number: 430612
A short review is given about viral intergenomic recombination experimentally demonstrated for the first time in 1949. In the present report some recent findings are reviewed, and it is suggested that a field strain of suid herpesvirus 1 (SHV-1), tentatively defined as the transmissible entity, is a composite population in which variants coexist, complement each other and exchange genetic material through high-frequency intergenomic recombination. This occasionally may result in a chaotic evolution of the virus. Comprehensive molecular epidemiological studies by means of restriction fragment pattern (RFP) analyses have been performed on SHV-1 strains from different parts of the world, and an evolutionarily consistent systematization has gradually been elaborated based on differences in stable genomic characteristics. One other implication of the new findings is that the destruction of a cell is the result of multiple invasions of the cell. This is a prerequisite of the recombination events and it would account for the survival of deletion mutants by complementation with other variants. A concept of multiple invasions is in agreement with the difficulties in achieving clonal populations from isolates exhibiting a hypervariable genomic region.