Chromosome-level genome assembly of the Chinese camelback chiton, Liolophura sinensis

Chitons (Polyplacophora) are marine molluscs that can be found worldwide from cold waters to the tropics, and play important ecological roles in the environment. Nevertheless, there remains only two chiton genomes sequenced to date. The chiton Liolophura sinensis is one of the most abundant polyplacophorans found throughout East Asia. Our PacBio HiFi reads and Omni-C sequencing data resulted in a high-quality near chromosome-level genome assembly of ~609 Mb with a scaffold N50 length of 37.34 Mb (96.4% BUSCO). A total of 28,233 genes were predicted, including 28,010 protein-coding genes. The repeat content (27.89%) was similar to the other Chitonidae species and approximately three times lower than in the genome of the Hanleyidae chiton. The genomic resources provided in this work will help to expand our understanding of the evolution of molluscs and the ecological adaptation of chitons.

石鳖隶属于多板纲（Polyplacophora），是一类广泛分布于全球寒带至热带海域的海洋软体动物，在海洋生态系统中发挥着重要作用。然而截至目前，已完成全基因组测序的石鳖物种仅存2种。中华条斑石鳖（Liolophura sinensis）是东亚海域分布最广泛、种群丰度最高的多板纲物种之一。本研究利用PacBio HiFi测序读长与Omni-C测序数据，组装获得了约609 Mb的高质量近染色体级基因组，其scaffold N50长度为37.34 Mb，BUSCO（Benchmarking Universal Single-Copy Orthologs）完整度达96.4%。本研究共预测得到28233个基因，其中包含28010个蛋白编码基因。该基因组的重复序列占比为27.89%，与其他石鳖科（Chitonidae）物种的重复序列含量相近，约为汉利石鳖科（Hanleyidae）物种基因组重复序列占比的三分之一。本研究提供的基因组资源，将有助于拓展学界对软体动物演化及石鳖生态适应性的认知。