Indigenous chicken breeds have both cultural significance and economic value since they possess unique genetic characteristics that enable them to adapt to the local environment and contribute to biodiversity, food security, and sustainable agriculture in Vietnam. To (Tò in Vietnamese) chicken, a Vietnamese indigenous chicken breed, is popularly raised in Thai Binh province; however, little known is about the genetic diversity of this breed. In this study, we sequenced the complete mitochondrial genome of To chicken for a better understanding of the diversity and origin of the breed. The results of sequencing showed that the mitochondrial genome of To chicken spans a total length of 16,784 base pairs and comprises one non-coding control region (known as the displacement-loop (D-loop) region), two ribosomal RNA genes, 13 protein-coding genes, and 22 transfer RNA genes. The phylogenetic tree analyses and estimated genetic distances based on 31 complete mitochondrial genome sequences indicated that To chicken has a close genetic distance with the Laotian native chicken breed, Lv'erwu breed in China, and Nicobari black and Kadaknath breeds in India. The result of the current study might be important for conservation, breeding, and further genetic studies of To chicken.
Keywords: Vietnamese indigenous chicken breed; mitochondrial genome structure; phylogeny.