Alterations in DNA sequence and RNA transcription of the Bam HI-H fragment accompany attenuation of oncogenic Marek's disease herpesvirus.
The nucleotide sequences of the BamHI-H fragment of the HPRS16 strain of Marek's disease virus (MDV) and of its attenuated derivative HPRS16/att have been determined. The results show that in addition to the tandem expansion of a 132 bp sequence from two copies in HPRS16 virus to eight copies in HPRS16/att, nucleotide substitutions, deletions, and insertions were also noted. Several potential open reading frames (ORFs) were identified. One of these (ORF 13) encoded a deduced protein, mol wt 32 kD, which is likely to be the serotype-1 specific phosphoprotein expressed in tumours (1) and mapped to an EcoRI fragment within BamHI-H (2). Our results suggest that this ORF is unlikely to be the B antigen (3). ORF 4, which had some similarity to CD4 and immunoglobulin M heavy chain, was encoded by a transcript that originated within the first copy of the 132 bp repeat. ORF 21, which mapped entirely within UL, encoded a deduced protein at least 322 amino acids long that had some similarity to varicella zoster virus (VZV) alpha trans-inducing protein. None of these ORFs was altered significantly by attenuation, except ORF 4 and another small ORF (ORF 3), 5' of the 132 bp repeats, which would probably fail to be transcribed because of truncation of an RNA transcript.
AFRC Institute for Animal Health, Compton Laboratory, Berkshire, UK.
N
N
Ross
M M
MM
Binns
M
M
Sanderson
K A
KA
Schat
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D015342:DNA Probes; D004279:DNA, Viral / Q000235:genetics*; D015257:DNA-Cytosine Methylases / Q000235:genetics*; D008381:Herpesvirus 2, Gallid / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012367:RNA, Viral / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics; D014774:Virulence / Q000235:genetics
D015342:DNA Probes; D004279:DNA, Viral; D012367:RNA, Viral; D014764:Viral Proteins; C042525:DNA modification methylase BamHI; D015257:DNA-Cytosine Methylases