Abstract

Giant water bugs (genus Kirkaldyia and Lethocerus) are well known species from aquatic habitats throughout the world’s subtropical and tropical areas. Only one species of the Kirkaldyia deyrolli is distributed in Japan. K. deyrolli has been designated as second category rare species according Law for Conservation of Endangered Species of Wild Fauna and Flora in Japan, in 2019. We analyzed, for the first time, the complete mitochondrial genomes of the giant water bug K. deyrolli from Japan using next-generation sequencing. The mitochondrial genome was a circular and 15,579 bp molecule that included 13 protein-coding genes (PCGs), 22 tRNA genes, and two ribosomal RNA genes, along with one AT-rich control region. The AT content value was 69.55%. The heavy strand was predicted to have nine PCGs and 15 tRNA genes, whereas the light strand was predicted to contain four PCGs, seven tRNA genes, and two rRNA genes. Start codons were variable for all PCGs: four ATA, three ATC, four ATG, two ATT genes as the start codon. Stop codons were of two types: TAA for 12 genes and TAG for one gene. Incomplete stop codon T was identified. The molecular phylogenetic relationship, inferred using 13 PCGs, was consistent with that reported in previous studies, which predicted a sister relationship to the genus Lethocerus.

摘要

巨型臭虫（Kirkaldyia和Lethocerus属）是来自全世界亚热带和热带地区水生生境的著名物种。日本只分布了一种柯克氏藻。根据日本保护野生动植物濒危物种保护法，K。deyrolli已于2019年被指定为第二类稀有物种。我们首次分析了巨型水water K. deyrolli的完整线粒体基因组。来自日本的新一代测序技术。线粒体基因组是一个环状的15579 bp分子，包括13个蛋白质编码基因（PCG），22个tRNA基因和2个核糖体RNA基因，以及一个富含AT的控制区。AT含量值为69.55％。预测重链具有9个PCG和15个tRNA基因，而预测轻链包含4个PCG，7个tRNA基因和2个rRNA基因。起始密码子对于所有PCG都是可变的：四个ATA，三个ATC，四个ATG，两个ATT基因作为起始密码子。终止密码子有两种类型：TAA代表12个基因，TAG代表一个基因。确定了不完全的终止密码子T。使用13种PCG推断出的分子系统发育关系与先前研究报道的一致，该研究预测与该属的姐妹关系Lethocerus。