Comparative analysis of complete mitochondrial genomes of three Trichoglossus species (Psittaciformes: Psittacidae)

The genus Trichoglossus belongs to the family Psittacidae and includes fourteen species distributed worldwide. According to the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species, most Trichoglossus species have shown a decreasing population trend recently. In particular, Trichoglossus forsteni is listed as "Endangered" in the IUCN Red List of Threatened Species. Moreover, Trichoglossus haematodus and Trichoglossus moluccanus are one of the most traded and illegally traded parrots. However, only a few genetic studies have been conducted regarding the conservation of this genus.

In the present study, complete mitochondrial genomes of three species (T. forsteni, T. haematodus, and T. moluccanus) were sequenced and compared with Trichoglossus rubritorquis, species whose mitochondrial genome is already reported. Results indicate that the complete mitochondrial genomes of the three species were similar in length (17,906 bp for T. haematodus to 17,909 bp for T. forsteni). Furthermore, the organization and order of these three mitochondrial genomes were identical, including thirteen protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA genes, and two control regions (CRs) categorized into three domains containing nine conserved motifs. In addition, the genus Trichoglossus formed a well-supported monophyletic lineage.

The results of this study may be useful for future genetic studies toward the conservation of the genus Trichoglossus.