Characterization and phylogenetic analysis of the complete mitochondrial genome of Benthodytes gosarsi Gebruk, 2008 (Echinodermata: Holothuroidea: Elasipodida) from deep-sea environments

Deep-sea organisms exhibit remarkable adaptations to extreme environmental conditions. It is important to elucidate the survival mechanisms of deep-sea life by exploring their genetic characteristics and origins. This study reports for the first time the complete mitochondrial genome of a deep-sea holothurian species (Benthodytes gosarsi). The mitochondrial genome of B. gosarsi is 17,133 bp in length and encodes 13 PCGs, 2 rRNAs, and 22 tRNAs. The heavy strand of B. gosarsi mtDNA consists of 31.62% A, 13.30% G, 37.38% T, and 17.70% C bases. Phylogenetic analysis with 18 mitogenomes from five sea cucumber orders determined the phylogenetic position of B. gosarsi within Holothuroidea. This study provides new insights into the genetic structure and phylogenetic relationships of B. gosarsi, contributing to a better understanding of deep-sea adaptation in holothurians.

深海生物对极端环境条件展现出卓越的适应性。通过探究深海生物的遗传特征与起源，阐明其生存机制具有重要意义。本研究首次报道了一种深海海参纲（Holothuroidea）物种（Benthodytes gosarsi）的完整线粒体基因组（mitogenome）。该物种的线粒体基因组全长17133 bp，共编码13个蛋白编码基因（Protein-Coding Genes, PCGs）、2个核糖体RNA（rRNA）基因以及22个转运RNA（tRNA）基因。B. gosarsi的线粒体DNA（mitochondrial DNA, mtDNA）重链碱基组成为：腺嘌呤（A）占31.62%、鸟嘌呤（G）占13.30%、胸腺嘧啶（T）占37.38%、胞嘧啶（C）占17.70%。本研究基于5个海参目共18个线粒体基因组开展系统发育分析，明确了B. gosarsi在海参纲中的系统发育位置。本研究为B. gosarsi的遗传结构与系统发育关系提供了新的见解，有助于更深入地理解海参类的深海适应性。