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 10000 times less likely to occur than RNA recombination between diverse European isolates.
BøtnerA.,
StrandbygaardB.,
SørensenK. J.,
HaveP.,
MadsenK. G.,
MadsenE. S.,
AlexandersenS.1997; Appearance of acute PRRS-like symptoms in sow herds after vaccination with a modified live PRRS vaccine. Veterinary Record 141:497–499
ForsbergR.,
OleksiewiczM. B.,
PetersenA.-M. K.,
HeinJ.,
BøtnerA.,
StorgaardT.2001; A molecular clock dates the common ancestor of European-type porcine reproductive and respiratory syndrome virus at more than 10 years before the emergence of disease. Virology in press
HortonR. M.,
HuntH. D.,
HoS. N.,
PullenJ. K.,
PeaseL. R.1989; Engineering hybrid genes without the use of restriction enzymes: gene splicing by overlap extension. Gene 77:61–68
LiK.,
ChenZ.,
PlagemannP.1999; High-frequency homologous genetic recombination of an arterivirus, lactate dehydrogenase-elevating virus, in mice and evolution of neuropathogenic variants. Virology 258:73–83
MadsenK. G.,
HansenC. M.,
MadsenE. S.,
StrandbygaardB.,
BøtnerA.,
SørensenK. J.1998; Sequence analysis of porcine reproductive and respiratory syndrome virus of the American type collected from Danish swine herds. Archives of Virology 143:1683–1700
MeulenbergJ. J. M.,
HulstM. M.,
de MeijerE. J.,
MoonenP. L. J. M.,
den BestenA.,
de KluyverE. P.,
WensvoortG.,
MoormannR. J. M.1993; Lelystad virus, the causative agent of porcine epidemic abortion and respiratory syndrome (PEARS), is related to LDV and EAV. Virology 192:62–72
NagyP. D.,
BujarskiJ. J.1995; Efficient system of homologous RNA recombination in brome mosaic virus: sequence and structure requirements and accuracy of crossovers. Journal of Virology 69:131–140
NielsenH. S.,
OleksiewiczM. B.,
ForsbergR.,
StadejekT.,
BøtnerA.,
StorgaardT.2001; Reversion of a live porcine reproductive and respiratory syndrome virus vaccine investigated by parallel mutations. Journal of General Virology 82:1263–1272
OleksiewiczM. B.,
BøtnerA.,
ToftP.,
GrubbeT.,
NielsenJ.,
KamstrupS.,
StorgaardT.2000; Emergence of porcine reproductive and respiratory syndrome virus deletion mutants: correlation with the porcine antibody response to a hypervariable site in the ORF 3 structural glycoprotein. Virology 267:135–140
PsikalI.,
MoutelikovaR.,
KosinovaE.,
MojzisM.,
SmidB.,
NejedlaE.,
IndikS.,
RodakL.1999; Molecular identification and genotyping of porcine reproductive and respiratory syndrome virus (PRRSV) strains in the Czech and Slovak Republics. Proceedings of the 3rd International Symposium of PRRSV and Aujeszky 1:175–176
RirieK. M.,
RasmussenR. P.,
WittwerC. T.1997; Product differentiation by analysis of DNA melting curves during the polymerase chain reaction. Analytical Biochemistry 245:154–160
WensvoortG.,
TerpstraC.,
PolJ. M. A.,
ter LaakE. A.,
BloemraadM.,
de KluyverE. P.,
KragtenC.,
van BuitenL.,
den BestenA.,
WagenaarF.,
BroeckhuijsenJ. M.,
MoonenP. L. J. M.,
ZetstraT.,
de BoerE. A.,
TibbenH. J.,
de JongM. F.,
van’t VeldP.,
GroenlandG. J. R.,
van GennepJ. A.,
VoetsM.,
VerheijdenJ. H. M.,
BramskampJ.1991; Mystery swine disease in the Netherlands: the isolation of Lelystad virus. Veterinary Quarterly 13:121–130
YuanS.,
NelsenC. J.,
MurtaughM. P.,
SchmittB. J.,
FaabergK. S.1999; Recombination between North American strains of porcine reproductive and respiratory syndrome virus. Virus Research 61:87–98
High frequency RNA recombination in porcine reproductive and respiratory syndrome virus occurs preferentially between parental sequences with high similarity