A GENOMIC MAP OF INFECTIOUS LARYNGOTRACHEITIS VIRUS AND THE SEQUENCE AND ORGANIZATION OF GENES PRESENT IN THE UNIQUE SHORT AND FLANKING REGIONS

We present a genomic map of infectious laryngotracheitis virus (ILT) a nd an 18,912 bp sequence containing the entire unique short region and a portion of the flanking short repeats. In determining the genomic m ap, an 856 bp region repeated as many as 13 times was identified withi n the short repeats. The unique short sequence contains nine potential open reading frames (ORFs). Six of these ORFs show homology to other known herpesvirus unique short genes. Using the herpes simplex virus n omenclature, these genes are the US2, protein kinase, and glycoprotein s G, D, I, and E (ORF 1, 2, 4, 6, 7, and 8, respectively). Interesting ly, an open reading frame with homology to HSV-1 UL47 (ORF 3) is found in the unique short. One very large open reading frame (ORF 5) is pre sent and contains a threonine-rich, degenerate repeat sequence. This g ene appears to be unique to ILT among sequenced herpesviruses. Two ORF s were identified within the short repeat (SR) region. SRORF 1 is homo logous to a gene (SORF 3) found in the unique short region in both MDV and HVT, and appears to be specific to avian herpesviruses. SRORF 2 h as homology to HSV US10.