DISTINCT GENE ARRANGEMENT IN THE BUZURA-SUPPRESSARIA SINGLE-NUCLEOCAPSID NUCLEOPOLYHEDROVIRUS GENOME

The genome organization of the Buzura suppressaria single-nucleocapsid nucleopolyhedrovirus (BusuNPV) was largely elucidated and compared to those of other baculoviruses, A detailed physical map was constructed for the restriction enzymes BamHI, Bg/I, Bg/II, EcoRI, HindIII, KpnI, PstI, XbaI and XhoI. The 120.9 kbp viral genome was cloned as restric tion fragments into a plasmid library from which about 43.5 kbp of dis persed sequence information was generated. Fifty-two putative open rea ding frames homologous to those of other baculoviruses were identified and their location in the genome of BusuNPV was determined. Although the gene content of BusuNPV is similar to that of Autographa californi ca multiple-nucleocapsid nucleopolyhedrovirus, Bombyx mori nucleopolyh edrovirus and Orgyia pseudotsugata multiple-nucleocapsid nucleopolyhed rovirus, the gene order is, however, significantly different from that observed in the other viruses, which have a high degree of collineari ty, A new approach (GeneParityPlot) was developed to represent the dif ferences in gene order among baculoviruses when limited sequence infor mation is available and to take advantage of the high degree of gene c onservation. The data obtained show that BusuNPV is a distinct baculov irus species and the analyses suggest that gene distribution along bac ulovirus genomes may be used as a phylogenetic marker.