Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/11/2001
Publication Date: N/A
Technical Abstract: We present here the complete DNA sequence, with analysis, of the Culex nigripalpus (CuniNPV) mosquito baculovirus genome. The CuniNPV genome is a circular dsDNA molecule of 108,252 base pairs (50.9% CG) and it encodes 126 putative genes. CuniNPV encodes 32 baculoviruses homologues, however its lack of conservation in gene order, and the absence of numerous genes present in all known lepidopteran baculoviruses, suggest significant evolutionary distance between Dipteran and Lepidopteran baculoviruses. Notably, CuniNPV lacks genes with functions involving virion formation, DNA replication and RNA transcription. CuniNPV lacks homologues of genes involved in the formation of virogenic stroma (pp31), nucleocapsid (orf1629, p87 and p24), envelope (odv-e25, odv-e66, odv-e18), and polyhedra (polyhedrin/granulin, p10, pp34 and fp25k). In addition, genes essential (ie-1, lef-3, and p143) and stimulatory (ie-2, lef-7, pe38) for DNA replication as well as genes essential for early (ie-0, ie-1, ie-2, and pe-38) and late (ie-1, ie-2, lef-3, lef-6, lef-11, pp31) gene transcription are missing. Absence of homologues of envelope and occlusion body proteins, suggest that CuniNPV ODV and OB may be structurally and compositionally different from those in lepidopteran hosts. CuniNPV contains genes with potential host range functions including a p35 homologue, a ribosomal-like protein, an insulin-binding protein, a lysozyme-like protein and a homologue of a Drosophila melanogaster gene of unknown function. The presence of novel cellular homologues suggests unique mechanisms of host manipulation in Dipteran baculoviruses and might have application for the development of new strategies for the prevention of diseases vectored by mosquitoes.