Faculty of Veterinary Medicine, Urmia University Veterinary Research Forum 2008-8140 16 10 2025 10 01 Complete mitochondrial genome sequence of Dermacentor marginatus (Acari: Ixodidae) isolated on Hainan Island, China: molecular characterization and phylogenetic implications 557 564 729410 10.30466/vrf.2025.2039447.4411 EN Xingzhi Feng NHC Key Laboratory of Tropical Disease Control, School of Tropical Medicine, Hainan Medical University, Haikou, China Yijia Xu NHC Key Laboratory of Tropical Disease Control, School of Tropical Medicine, Hainan Medical University, Haikou, China Qianfeng Xia NHC Key Laboratory of Tropical Disease Control, School of Tropical Medicine, Hainan Medical University, Haikou, China Yajun Lu NHC Key Laboratory of Tropical Disease Control, School of Tropical Medicine, Hainan Medical University, Haikou, China Department of Pathogen Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China 0000-0002-8879-6570 Journal Article 2024 08 24 The complete mitochondrial genome sequence of <em>Dermacentor marginatus</em> isolated from Hainan Island, a tropical island in China, has recently been elucidated. This ornate sheep tick is a three-host species, meaning it requires feeding on different hosts throughout its larval, nymph, and adult stages. This broad host range contributes significantly to its role in the transmission of various pathogens including spotted fever group rickettsia. The mitochondrial genome of D. marginatus was sequenced and found to be a circular, double-stranded DNA molecule with a total length of 15,005 bp. The genome exhibited a guanine and cytosine (GC) content of 21.23%, reflecting its unique genetic composition. Annotation of the genome revealed the presence of 37 genes, comprising 22 tRNA genes, 13 mRNA genes as protein-coding genes, (PCGs) and two rRNA genes. Phylogenetic analysis placed <em>D. marginatus </em>closest to <em>D. silvarum</em> from Heilongjiang province in China, clustering with D. sinicus from Hubei province in China. <em>D. marginatus</em> also exhibited proximity to <em>D.</em> species from China and other countries forming a distinct cluster. The availability of the complete mitochondrial genome sequence of <em>D. marginatus</em> marked a notable advancement in deciphering the genetic diversity and evolutionary path of this tick species. The study concentrated on the mitochondrial genome of <em>D. marginatus</em> from Hainan Island, examining its genetic and phylogenetic features, and assessing genomic variations that may influence mitochondrial function and tropical adaptation. The investigation into the genetic adaptations of D. marginatus to its tropical niche yielded vital information for forecasting how tick populations may react to changes in climate and diverse environmental conditions. https://vrf.iranjournals.ir/article_729410_fe46dfc8fe462ef18e59076e96ed7246.pdf