Edwards Richard J, Chen Stephanie H, Halliday Bruce, Bragg Jason G
School of Biotechnology and Biomolecular Sciences, Evolution & Ecology Research Centre, University of New South Wales, Kensington, NSW 2052, Australia.
Minderoo OceanOmics Centre at UWA, Oceans Institute, University of Western Australia, Perth, WA 6009, Australia.
Genome Biol Evol. 2025 Feb 3;17(2). doi: 10.1093/gbe/evaf023.
A draft assembly of the rainforest tree Rhodamnia argentea Benth. (malletwood, Myrtaceae) revealed contaminating DNA sequences that most closely matched those from mites in the family Eriophyidae. Eriophyoid mites are plant parasites that often induce galls or other deformities on their host plants. They are notable for their small size (averaging 200 μm), distinctive four-legged body structure, and heavily streamlined genomes, which are among the smallest known of all arthropods. Contaminating mite sequences were assembled into a high-quality gapless telomere-to-telomere nuclear genome. The entire genome was assembled on two fully contiguous chromosomes, capped with a novel TTTGG or TTTGGTGTTGG telomere sequence, and exhibited clear signs of genome reduction (34.5 Mbp total length, 68.6% arachnid Benchmarking Universal Single-Copy Ortholog completeness). Phylogenomic analysis confirmed that this genome is that of a previously unsequenced eriophyoid mite. Despite its unknown identity, this complete nuclear genome provides a valuable resource to investigate invertebrate genome reduction.
雨林树木银叶密脉蒲桃（槌木，桃金娘科）的基因组草图显示，其中存在污染性DNA序列，这些序列与瘿螨科螨类的序列最为匹配。瘿螨是植物寄生虫，常使其寄主植物形成虫瘿或其他畸形。它们以体型小（平均200微米）、独特的四足身体结构和高度简化的基因组而闻名，其基因组是已知所有节肢动物中最小的之一。污染性螨类序列被组装成一个高质量的无间隙端粒到端粒核基因组。整个基因组组装在两条完全连续的染色体上，两端带有新的TTTGG或TTTGGTGTTGG端粒序列，并表现出明显的基因组缩减迹象（全长34.5兆碱基对，蛛形纲基准通用单拷贝直系同源基因完整性为68.6%）。系统基因组分析证实，该基因组属于一种此前未测序的瘿螨。尽管其身份不明，但这个完整的核基因组为研究无脊椎动物基因组缩减提供了宝贵资源。
