High frequency RNA recombination in porcine reproductive and respiratory syndrome virus occurs preferentially between parental sequences with high similarity.
Two types of porcine reproductive and respiratory syndrome virus (PRRSV) exist, a North American type and a European type. The co-existence of both types in some countries, such as Denmark, Slovakia and Canada, creates a risk of inter-type recombination. To evaluate this risk, cell cultures were co-infected with either a North American and a European type of PRRSV or two diverse types of European isolate. Subsequently, an approximately 600 bp region of the PRRSV genome was tested for recombination by quantitative real-time RT-PCR. Between 0.1 and 2.5% RNA recombination was found between the European isolates, but no recombination was detected between the European and North American types. Calculation of the maximum theoretical risk of European-American recombination, based on the sensitivity of the RT-PCR system, revealed that RNA recombination between the European and North American types of PRRSV is at least 10 000 times less likely to occur than RNA recombination between diverse European isolates.
van Vugt
Joke J F A
JJFA
Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1.
Storgaard
Torben
T
Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1.
Oleksiewicz
Martin B
MB
Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1.
Bøtner
Anette
A
Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1.
D000818:Animals; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000235:genetics; D008969:Molecular Sequence Data; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013552:Swine
D018076:DNA, Complementary; D012367:RNA, Viral