Chromosomal level of Korean Diadegma fenestrale (Jeju strain, JK-2023a) of genome assembly was achieved through a combined approach utilizing Nanopore long-read sequencing and Illumina NovaSeq short-read sequencing (approximately 217.2× coverage). The assembled genome spans 221.1 Mb, comprises 68 scaffolds, with most of the genome contained within 11 chromosomal level scaffolds. The completeness of the assembly is reflected in BUSCO assessment, with values reaching 99.6%. Scaffold N50 was 17.4 Mb, and GC % was 40%. RNAseq was performed using RNA extracted from larvae, pupae, and adults at various developmental stages (trimmed RNA-Seq data, 11.3 Gb), and a total of 13,544 genes were predicted by synthesizing the transcriptome information with the annotation information of five closely related species such as, Campoletis sonorensis (GCA_013761285.1), Venturia canescens (GCF_019457755.1), and Nasonia vitripennis (GCF_000002325.3, and GCF_009193385.2). Of these, 13,498 genes were identified by BLAST and are being further analyzed. Although the frequency of DfIV genome integration into the host’s 11 chromosomes varies from 0 to 32%, it was confirmed that all 62 DfIV genome fragments were inserted into the Hymenopteran host genome.
Chromosomal level genome draft was assembled using a Korean Diadegma fenestrale (Jeju strain, KJ09). This assembly was achieved through a combined approach utilizing Nanopore long-read sequencing (approximately 134X coverage) and Illumina NovaSeq short-read sequencing (approximately 83X coverage). The assembled genome spans 243 Mb, comprises 160 scaffolds, with most of the genome contained within 11 chromosomal level scaffolds. The completeness of the assembly is reflected in BUSCO assessment, with values reaching 99.6%. Gene annotation is not completed. A symbiotic virus, Diadegma fenestrale Ichnovirus (DfIV) genome revealed 62 non-overlapping circular DNA segments the aggregate genome size was approximately 240 kb. Although the frequency of DfIV genome integration into the host’s 11 chromosomes varies from 0 to 32%, it was confirmed that all 62 DfIV genome fragments were inserted into the host genome. A total of 123 ORFs were predicted from the DfIV genome and most of those were expressed in the host’s ovary. This result may be contradictory to existing theories, but we propose a new hypothesis that some genes possessed by viruses may play different roles depending on the type and state of the host. Additionally, this phenomenon can be considered in relation to coevolution with the hosts.
The genus Diadegma is a well known parasitoid group in various lepidopteran insect such as Plutella xylostella andsome are known to have symbiotic virus. Previously we reported a novel ichnovirus as named Diadegma fenestrale Ichnovirus(DfIV, 62 segments, 247,238bp) from D. fenestrale which parasitized in the P. xylostella. Here we report another ichnovirus,DsIV from Taiwan strain of D. semiclausum which parasitized in the P. xylostella. Total 64 genomic segments were sequenced,185,053bp from DsIV. Two Ichnovirus showed high similarity in 99 regions in most of segments. We already confirmedintegration of DfIV genome segments into the chromosome from the P. xylostella via genome sequencing of the lepidopteranhost. Therefore some of recombination could be passible inside of the lepidopteran genome.
The genus Diadegma is a well known parasitoid group and some are known to have symbiotic virus. A novel IV was discovered from the calyx of D. fenestrale female. This virus was named as D. fenestrale Ichnovirus (DfIV) and its genome contains 62 circular DNA segments with an aggregate size of approx. 240kb. We examined its gene expression patterns depending on the hosts (hymenopteran host, D. fenestrale and lepidopteran host, Plutella xylostella) and stages of P. xylostella based on RNAseq. Among 62 genome segments, only two segments such C15 and D14 were highly expressed in ovary of D. fenestrale. On the other hands, five segments were differently expressed depending on the developmental stages (3 rd and 4 th instar larvae). Additionally we confirmed integration of DfIV genome segments into the chromosome from the Plutella xylostella via genome sequencing of the lepidopteran host.
The genus Diadegma is a well known parasitoid group and some are known to have symbiotic virus, PDV. A novel IV was discovered from the calyx of D. fenestrale female. D. fenestrale has more than two hosts, including PTM and DBM. The oviposition and survival rate results showed that D. fenestrale preferred PTM to DBM as hosts. Nevertheless, the developmental period and morphology of D. fenestrale were not significantly different between PTM and DBM. To identify these phenomena, DfIV genome expression patterens were compared between PTM and DBM under various conditions. DfIV genes were more widely expressed in PTM than in DBM after parasitized by D. fenestrale, particularly at the initial point. In addition, large numbers of DfIV genes were expressed only in PTM and they showed differential expression patterns between two lepidopteran hosts. This DfIV genome expression plasticity showed a dependency on the lepidopteran host species and parasitization time, suggesting that it may contribute to the parasitoid survival rate increase. This may be one of the key elements that determine the symbiotic relationship between PDV and parasitoid.
The Diadegma fenestrale is known as parasitoid on potato tuber moth, Phthorimaea operculella and diamondback moth, Plutella xylostella. The Diadegma genus is reported to have symbiotic virus, ichnovirus, D. fenestrale Ichnovirus (DfIV) was identified from this species which is a first report. DfIV showed typical ichnovirus shape with two membranes surrounding the virus capsid. To identify DfIV genes, whole genome sequencing based on GS-FLX was conducted using purified total DfIV genomic DNA extracted from D. fenestrale calyx. About sixty ORFs were analyzed and several typical ichnovirus gene families were detected such as cys-motif, repeat element, vinnexin and vankyrin. Present study was focused on the gene expression patterns in two different lepidopteran hosts.
The Diadegma fenestrale was known as parasitoid on potato tuber moth, Phthorimaea operculella and diamondback moth, Plutella xylostella. This species, genus Diadegma are first reported from Korea. DfIV showed typical ichnovirus shape which two membranes surround virus capsids. The genome contents of DfIV consist about sixteen double-stranded DNA segments ranging 2 to 6 kb. To identify DfIV genes, whole genome sequencing based on GS-FLX was conducted using purified total viral DNA extracted from D. fenestrale calyx. About sixty ORFs were analyzed and several typical polydna virus gene family detected such as cys-motif, rep, vinnexin and vankyrin. This is the first report of DfIV and these lepidopteran host immune suppression genes will be deeply identified.