A betabaculovirus encoding a gp64 homolog

Abstract

BackgroundA betabaculovirus (DisaGV) was isolated from Diatraea saccharalis (Lepidoptera: Crambidae), one of the most important insect pests of the sugarcane and other monocot cultures in Brazil.ResultsThe complete genome sequence of DisaGV was determined using the 454-pyrosequencing method. The genome was 98,392 bp long, which makes it the smallest lepidopteran-infecting baculovirus sequenced to date. It had a G + C content of 29.7 % encoding 125 putative open reading frames (ORF). All the 37 baculovirus core genes and a set of 19 betabaculovirus-specific genes were found. A group of 13 putative genes was not found in any other baculovirus genome sequenced so far. A phylogenetic analysis indicated that DisaGV is a member of Betabaculovirus genus and that it is a sister group to a cluster formed by ChocGV, ErelGV, PiraGV isolates, ClanGV, CaLGV, CpGV, CrleGV, AdorGV, PhopGV and EpapGV. Surprisingly, we found in the DisaGV genome a G protein-coupled receptor related to lepidopteran and other insect virus genes and a gp64 homolog, which is likely a product of horizontal gene transfer from Group 1 alphabaculoviruses.ConclusionDisaGV represents a distinct lineage of the genus Betabaculovirus. It is closely related to the CpGV-related group and presents the smallest genome in size so far. Remarkably, we found a homolog of gp64, which was reported solely in group 1 alphabaculovirus genomes so far.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2408-9) contains supplementary material, which is available to authorized users.

The Complete Genome Sequence of a Second Distinct Betabaculovirus from the True Armyworm, Mythimna unipuncta

“…Previous analysis of viral and host dut genes from a variety of sources supports the horizontal transfer of dut genes from host to virus genomes and the subsequent duplication, deletion and movement of dut genes within viral genomes [50]. Two comprehensive phylogenetic analyses of baculovirus dut genes have been published recently [51, 52]. Both analyses indicate that baculovirus dut genes do not constitute a monophyletic group, but likely originate from multiple sources.…”

“…Both analyses indicate that baculovirus dut genes do not constitute a monophyletic group, but likely originate from multiple sources. Ardisson-Araujo and coworkers (2016) [51] conclude from their analysis that baculovirus dut genes are the result of ten different acquisition events. It is possible that the MyunGV#8 dut gene was also a consequence of a separate horizontal gene transfer.…”

Genome analysis of a novel Group I alphabaculovirus obtained from Oxyplax ochracea

“…The Alphabaculovirus genus can be divided into two groups, Groups I and II [ 8 – 10 ]. Group I alphabaculoviruses are characterized by their use of GP64 as their envelope fusion protein (EFP), while Group II alphabaculoviruses, most betabaculoviruses (except a newly discovered Diatraea saccharalis granulovirus, which contains both gp64 and f ) and deltabaculoviruses exploit F protein as their EFP [ 11 , 12 ]. Group I alphabaculoviruses are further divided into two clades based on phylogeny, “a” and “b” [ 13 ].…”

A novel cypovirus found in a betabaculovirus co-infection context contains a poxvirus immune nuclease (poxin)-related gene

“…The phylogenetic tree of the predicted protein coded for S8 shows that ErelCPV-2, betabaculovirus and entomopoxvirus genomes share the same accessory gene, possibly acquired by HGT from insects. The HGT events have already been described for other insect viral families, for example, densovirus-related genes with baculoviruses [42][43][44][45][46].…”