ABSTRACT
Ascoviruses are enveloped, circular, double-stranded DNA viruses that can effectively control the appetite of lepidopteran larvae, thereby reducing the consequent damage and economic losses to crops. In this study, the virion of a sequenced Heliothis virescens ascovirus 3i (HvAV-3i) strain was used to perform proteomic analysis using both in-gel and in-solution digestion. A total of 81 viral proteins, of which 67 were associated with the virions, were identified in the proteome of HvAV-3i virions. Among these proteins, 23 with annotated functions were associated with DNA/RNA metabolism/transcription, virion assembly, sugar and lipid metabolism, signalling, cellular homoeostasis and cell lysis. Twenty-one viral membrane proteins were also identified. Some of the minor 'virion' proteins identified may be non-virion contaminants of viral proteins synthesized during replication, identified by more recent and highly sensitive methods. The extensive identification of the ascoviral proteome will establish a foundation for further investigation of ascoviral replication and infection.
Subject(s)
Ascoviridae/chemistry , Proteome/analysis , Viral Proteins/analysis , Virion/chemistry , Computational Biology , ProteomicsABSTRACT
Ascoviruses are circular double-stranded DNA viruses that infect insects. Herein we sequenced and analyzed the genome of the previously unrecorded ascovirus isolate Heliothis virescens ascovirus 3i (HvAV-3i). The genome size is 185,650 bp with 181 hypothetical open reading frames (ORFs). Additionally, definition based on ascovirus repeated ORFs (aros) is proposed; whereby the 29 aros from all sequenced Ascoviridae genomes are divided into six distinct groups. The topological relationship among the isolates of Heliothis virescens ascovirus 3a is (HvAV-3f, {HvAV-3h, [HvAV-3e, (HvAV-3g, HvAV-3i)]}) with every clade well supported by a Bayesian posterior probability of 1.00 and a Bootstrap value of 100%.
Subject(s)
Ascoviridae/genetics , Ascoviridae/isolation & purification , Open Reading Frames , Spodoptera/virology , Animals , Ascoviridae/classification , Genome, Viral , Genomics , Hemolymph/virology , Larva/virology , PhylogenyABSTRACT
In this study, the complete mitochondrial genome (mitogenome) of Paragabara curvicornuta was sequenced for the first time by traditional PCR amplification and primer walking methods. As a circular DNA molecule, the entire mitogenome is 15,532 bp in length (GeneBank accession no. KT362742), and consists of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and an AT-rich region. The nucleotide composition is A (39.9%), C (12.0%), G (7.6%), and T (40.4%). Based onthe amino acid sequences of 13 PCGs from 43 noctuoid species as ingroups and two drepanoid species as outgroups, the phylogenetic trees was constructed. The phylogenetic relationships of the families among Noctuoidea are (Notodontidae, (Erebidae, (Nolidae, Noctuidae)). However, the phylogenetic position of P. curvicornuta is still unclear in the family Erebidae that is a monophyletic clade strongly supported by the bootstrap value of 100%.
ABSTRACT
Ascoviruses are double-stranded DNA viruses that mainly infect noctuid larvae, and are transmitted by the parasitoid wasp Microplitis similis Lyle. Ascovirus-parasitoids wasp-noctuid insects constitute the dissemination system. Selection of suitable reference genes for the dissemination system could play an important role in elucidating the pathogenic molecular mechanisms of ascovirus. Unfortunately, such studies on potential reference genes in the dissemination system of ascoviruses are lacking. In the present study, we evaluated 11 candidate reference genes: ß-actin1 (ACT1), ß-actin2 (ACT2), elongation factor 1 (EF1), elongation factor 2 (EF2), ribosomal protein L10 (L10), ribosomal protein L17A (L17A), superoxide dismutase (SOD), 28S ribosome (28S), Tubulin (TUB) and 18S ribosome (18S). The samples were originally from various virus concentrations and points-in-time of experimental treatments using RefFinder and four algorithms. The results showed that EF1 was the most stable internal gene in S. exigua and M. similis and that EF2 was the most stable in the IOZCAS-Spex-II-A cell line, and the stability of reference genes were confirmed via the expression levels of two inhibitor of apoptosis-like (iap-like) genes from Heliothis virescens ascovirus 3 h (HvAV-3h). This study provides a crucial basis for future research that explores the molecular mechanisms of the pathogenesis of ascoviruses.
Subject(s)
Ascoviridae/genetics , Gene Expression Profiling/methods , Real-Time Polymerase Chain Reaction/methods , Reference Standards , Reverse Transcriptase Polymerase Chain Reaction/methods , Animals , Gene Expression Profiling/standards , Hymenoptera/virology , Lepidoptera/virology , Real-Time Polymerase Chain Reaction/standards , Reverse Transcriptase Polymerase Chain Reaction/standardsABSTRACT
The complete genome sequence of Heliothis virescens ascovirus 3f (HvAV-3f) was obtained. The HvAV-3f genome has a circular genome of 198,157bp with a G+C content of 46.0%, and encodes 190 open reading frames (ORFs) longer than 69 amino acids. Two major homologous regions (hrs) and 29 'baculovirus repeat ORFs' (bro) were found in the genome. BLAST analyses revealed that three HvAV-3f genes were homologous to that of lepidopteran insects. Nine ORFs were unique to HvAV-3f, in which two ORFs showed significant levels of similarity to genes that have not been previously described for ascoviruses in the Genbank database.
