Characterization of Herpesvirus of Turkeys Replication Using Recombinant DNA

Abstract

DNA has been isolated from herpesvirus of turkeys (HVT) virions and used to construct a partial gene library in pBR-322. The recombinants have been characterized and shown to contain HVT DNA inserts. A representative recombinant containing a 5.9-kilobase HindIII fragment was used as a probe to quantitate the yields of HVT DNA in vitro and to follow the kinetics of viral DNA replication. The data shown that in chicken fibroblasts, viral DNA synthesis initiates by about 12-14 hr postinfection and that the yield of progeny virus plateaus at 28-30 hr postinfection. Based upon quantitative hybridization to cloned DNA probes, we estimate that approximately 2000 HVT genomes are produced per infected cell in vitro; however, in vivo in persistently infected turkeys, the number of viral genomes was below the level of detection by Southern blotting.

Cosmid cloning and restriction endonuclease mapping of the herpesvirus of turkeys (HVT) genome

“…These findings are supported by the fact that cloning in a plasmid/cosmid [9] as well as cosmid vector [17] resulted in the establishment of genomic libraries of HVT, not completely representing the BamHI-C fragment. Although HVT FC 126 is the strain of choice used for HVT cloning studies [4,9,14,17], the restriction site maps for PstI and BamHI shown in Fig. 1B significantly differ from those published by Igarashi et al [9] in number, size, and arrangement of the restriction fragments.…”