Complete ORF1b-gene sequence indicates yellow head virus is an invertebrate nidovirus.

We report the sequence of an 8503 nucleotide (nt) region of the genome of yellow head virus (YHV) encompassing the open reading frame (ORF) 1b gene. Comparison with the sequence of Australian gill-associated virus (GAV) indicated that the region, comprising approximately 30% of the YHV genome, commences 268 nt upstream of the putative ORF1a termination codon and continues through ORF1b to a site 30 nt downstream of the ORF2 initiation codon. YHV ORF1a and ORF1b overlap by 37 nt.