Long-read genome assembly of the Japanese parasitic wasp Copidosoma floridanum (Hymenoptera: Encyrtidae).

ABSTRACT

Copidosoma floridanum is a cosmopolitan species and an egg-larval parasitoid of the Plusiine moth. C. floridanum has a unique development mode called polyembryony, in which over two thousands of genetically identical embryos are produced from a single egg. Some embryos develop into sterile soldier larvae precociously, and their emergence period and aggressive behavior are differed between the US and Japanese C. floridanum strains. Genome sequencing expects to contribute our understanding of the molecular bases underlying progression of polyembryony. However, only the genome sequence of the US strain from generating by short-read assembly has been reported. In the present study, we determined the genome sequence of the Japanese strain using Pacific Biosciences high-fidelity reads and generating a highly contiguous assembly (552.7 Mb, N50 17.9 Mb). Gene prediction and annotation identified 13,886 transcripts derived from 10,786 gene models. We searched the genomic differences between US and Japanese strains. Among gene models predicted in this study, 100 gene loci in the Japanese strain had extremely different gene structure from those in the US strain. This was accomplished through the functional annotation (GGSEARCH) and long-read sequencing. Genomic differences between strains were also reflected to amino acid sequences of vasa that plays a central role in caste determination in this species. The genome assemblies constructed in this study will facilitate the genomic comparisons between Japanese and US strains, leading to our understanding of detail genomic regions responsible for the ecological and physiological characters of C. floridanum.