Genome assembly of Diadegma fenestrale (Hymenoptera: Ichneumonidae), and genome integration of its symbiotic virus, DfIV

Abstract

Diadegma fenestrale is a parasitic wasp of ecological and agricultural significance, regulating pest populations. However, limited genomic resources have hindered a deeper understanding of its biology and symbiotic interactions. This study presents a chromosome-level genome assembly of D. fenestrale using Nanopore and Illumina sequencing. The assembled 221.1 Mb genome comprises 68 scaffolds, including 11 at the chromosomal level, and exhibits high completeness with a BUSCO completeness score of 99.6 %. A total of 13,544 protein-coding genes were predicted, with BUSCO assessment of the gene set indicating 97.5 % completeness (single-copy: 96.8 %, duplicated: 0.7 %), 0.7 % fragmented, and 1.8 % missing genes. Comparative genomic analysis with closely related hymenopteran species provides new insights into genome evolution, including gene family expansion, contraction patterns, and chromosomal rearrangements. Additionally, this study examines DfIV, a symbiotic virus associated with D. fenestrale, identifying 62 genome segments integrated into the host genome. Most segments are present in one or two copies, while four segments exhibit three copies, suggesting a dynamic interaction between the virus and the host genome that may influence gene regulation and chromosomal stability. This study provides a comprehensive genomic resource for D. fenestrale, enhancing our understanding of its genomic architecture, evolutionary dynamics, and functional adaptations. The findings contribute to broader research on parasitoid wasps, and symbiotic virus-host interactions, with implications for biological pest control and evolutionary biology.