Whole Genome Sequences of Cryptotympana Atrata Fabricius, 1775 (Hemiptera: Cicadidae) in the Korean Peninsula: Insights into Population Structure with Novel Pathogenic Or Symbiotic Candidates

Abstract

Background: The blackish cicada (Cryptotympana atrata) exhibits unique characteristics and is one of the model cicadas found in the Korean Peninsula. It is a species of southern origin, prefers high temperatures, and is listed as a climate-sensitive indicator species in South Korea. Therefore, this species can be utilized to study the impact of climate change on the genetic diversity and structure of populations. However, research on the genome of C. atrata is limited. Methods: We sequenced the genome of an individual collected from South Korea and constructed a draft genome. Additionally, we collected ten specimens from each of the five regions in South Korea and identified single nucleotide variants (SNVs) for population genetic analysis. The sequencing library was constructed using the MGIEasy DNA Library Prep Kit and sequenced using the MGISEQ-2000 platform with 150-bp paired-end reads. Results: The draft genome of C. atrata was approximately 5.0 Gb or 5.2 Gb, making it one of the largest genomes among insects. Population genetic analysis, which was conducted on four populations in South Korea, including both previously distributed and newly expanded regions, showed that Jeju Island, a remote southern island with the highest average temperature, formed an independent genetic group. However, there were no notable genetic differences among the inland populations selected based on varying average temperatures, indicating that the current population genetic composition on the Korean Peninsula is more reflective of biogeographic history rather than climate- induced genetic structures. Additionally, we unexpectedly observed that most individuals of C. atrata collected in a specific locality were infected with microbes not commonly found in insects, necessitating further research on the pathogens within C. atrata. Conclusion: This study introduces the draft genome of C. atrata, a climate-sensitive indicator species in South Korea. Population analysis results indicate that the current genetic structure of C. atrata is driven by biogeographic history rather than just climate. The prevalence of widespread pathogen infections raises concerns about their impact on C. atrata. Considering the scarcity of publicly available genomic resources related to the family Cicadidae, this draft genome and population data of C. atrata are expected to serve as a valuable resource for various studies utilizing cicada genomes.