Functional evaluation of the role of reticuloendotheliosis virus long terminal repeat (LTR) integrated into the genome of a field strain of Marek's disease virus.
MDV-GX0101 is a field strain of Marek's disease virus with a naturally occurring insertion of the reticuloendotheliosis virus (REV) LTR fragment. In order to study the biological properties of REV-LTR insertion in the MDV genome, we constructed a full-length infectious BAC clone of MDV-GX0101 strain and deleted the LTR sequences by BAC mutagenesis. The pathogenic properties of the LTR-deleted virus were evaluated in infected SPF birds. The study demonstrated that the LTR-deleted virus had a stronger inhibitory effect on the growth rates of the infected birds and induced stronger immunosuppressive effects. Surprisingly, however, the ability for horizontal transmission of the LTR-deleted virus appeared to be significantly weaker than its parental LTR-intact virus. Even though the precise molecular mechanisms are still not clear, the results of our studies demonstrate that the retention of the REV-LTR in the MDV genome decreases its pathogenic effects but increases its potential for horizontal transmission.
Sun
Ai-Jun
AJ
Shandong Agricultural University, Taian 271018, PR China.
Xu
Xiao-Yun
XY
Petherbridge
Lawrence
L
Zhao
Yu-Guang
YG
Nair
Venugopal
V
Cui
Zhi-Zhong
ZZ
D000818:Animals; D001717:Birds / Q000821:virology; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D007165:Immunosuppression Therapy; D025922:Mardivirus / Q000235:genetics* / Q000472:pathogenicity*; D008380:Marek Disease / Q000276:immunology / Q000473:pathology* / Q000635:transmission / Q000821:virology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011995:Recombination, Genetic; D001356:Reticuloendotheliosis virus / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D020079:Terminal Repeat Sequences / Q000235:genetics*
D004279:DNA, Viral