关键词: 敬钊缨毛蛛, 染色体核型, 基因组大小, 流式细胞仪, K-mer 分析, 单分子测序技术

Abstract: The medicinal preparation of Chilobrachys jingzhao possesses various therapeutic properties, including anti-inflammatory, detoxifying, analgesic, and anti-edema effects. However, research on its genetic background and toxin mechanisms is held back by the lack of chromosome karyotype and genome data. In this study, we analyzed the karyotype of C. jingzhao using chromosome preparation techniques, estimated the genome size using flow cytometry and K-mer analysis, and performed genome sequencing and assembly using second- and third-generation single molecule real-time sequencing technologies. The results showed that C. jingzhao has a diploid chromosome number of 2n=68, with a karyotype formula of 2n=46m+18sm+2st and a chromosomal complement of 2n=10L+18M2+38M1+2S. Using Solanum lycopersicum and Trichonephila clavata as references, flow cytometry estimates the genome size at 7,680.26 Mb and 7,775.49 Mb. The 19-mer analysis also estimated the genome size to be 7,626.00 Mb, consistent with the flow cytometry results. Further analysis indicated that the genome of C. jingzhao has a high level of heterozygosity (8.45%) and a high proportion of repetitive sequences (67.10%), classifying it as an ultra-high heterozygous and high-repeat genome. The initial genome assembly of C. jingzhao was 8,804.93 Mb in size, with a contig N50 of 55.55 Mb and a BUSCO completeness score of 95.9%, indicating high assembly quality. This study first reveals the karyotype and genome information of C. jingzhao, offering crucial data for future research on its whole genome, toxin mechanisms, genetics, origin, evolution, and taxonomy.

Key words: Chilobrachys jingzhao, Chromosome karyotype, Genome size, Flow cytometry, K-mer analysis, Single molecule real time