Characteristics and Phylogenetic Considerations of the Newly Sequenced Mitochondrial Genome of Teratoscincus scincus (Gekkota: Sphaerodactylidae)

Sphaerodactylidae play a crucial role in ecosystems, possessing significant ecological, scientific, and conservation value. They contribute to pest control and the maintenance of ecological balance, and also provide abundant materials for research in evolutionary biology and biodiversity. To refine the phylogenetic position of <i>Teratoscincus scincus</i> within the Sphaerodactylidae using mitogenomic data, this study sequenced the complete mitochondrial genome of <i>T. scincus</i> using the Illumina NovaSeq Xplus platform, and subsequently performed assembly, annotation, and analysis. The phylogenetic relationships of <i>T. scincus</i> within the Sphaerodactylidae were analyzed using 13 protein-coding genes (PCGs) from the mitochondrial genome via Bayesian inference (BI) and maximum likelihood (ML) methods. The complete mitochondrial genome of <i>T. scincus</i> is 16,943 bp in length and consists of 13 PCGs, 22 tRNA genes, 2 rRNA genes, and 1 control region (D-loop). The base composition shows a distinct AT preference, with the highest A + T content (56.3%) found in the PCGs region. A phylogenetic tree was constructed based on the amino acid sequences of 13 PCGs from the mitochondrial genomes of nine Sphaerodactylidae species retrieved from GenBank and the newly sequenced <i>T. scincus</i> generated in this study. The results confirm that <i>T. scincus</i> belongs to the genus <i>Teratoscincus</i> within the family Sphaerodactylidae. Phylogenetic analysis reveals that <i>T. scincus</i> and <i>Teratoscincus keyserlingii</i> cluster into a monophyletic group, suggesting a close phylogenetic relationship. Additionally, the phylogenetic tree provides new molecular evidence for understanding the formation mechanism of Sphaerodactylidae diversity. This study not only enriches the mitochondrial genome database of Sphaerodactylidae but also lays an important foundation for subsequent research on the adaptive evolution and conservation biology of <i>T. scincus</i>.