Estimation of the Genome Sizes of the Two Chigger Mites Based on Quantitative PCR and K-mer Analysis

다국어 초록 (Multilingual Abstract)

Leptotrombidium pallidum and Leptotrombidium scutellare are the major vector mites for Orientia tsutsugamushi, the causative agent of scrub typhus. Before these organisms can be subjected to whole-genome sequencing, the genome sizes of L. pallidum and L. scutellare were estimated by a method based on quantitative real-time PCR. In addition, k-mer analysis of the genome sequences obtained from Illumina sequencing was conducted to verify the mutual compatibility and reliability of results. The genome sizes estimated by qPCR were 191.3±7 Mb for L. pallidum and 262.1±13 Mb for L. scutellare. The estimated genome sizes based on k-mer analysis were 175.5 Mb for L. pallidum and 286.6 Mb for L. scutellare. The estimates from two independent methods were mutually complementary and in a similar range to those of other Acariform mites. The relatively small genome size would facilitate genome analysis, which could contribute to understanding Arachnida genome evolution and mite vector competence and provide key information for scrub typhus prevention.