MT-TN: MT-TN is a type of tRNA gene found in the mitochondrial DNA (mtDNA) of various species, including humans and monkeys [PMC8073089]. In monkeys, two amplicons in the DNA samples align with human mtDNA tRNA genes MT-TA, MT-TN, and MT-TW [PMC8073089]. Another amplicon aligns with human mtDNA tRNA genes MT-TN and MT-C [PMC8073089]. In cynomolgus monkeys, there are 64 differences in the UAS (unassigned sequence) compared to the revised Cambridge Reference Sequence (rCRS), including insertions, single nucleotide variations (SNVs), and deletions [PMC8073089]. The expression levels of several tRNA genes, including MT-TN, are consistently down-regulated at 2 and 5 months in monkeys [PMC8522632]. A specific mutation in the MT-TN gene at position m.5690A > G has been identified [PMC4606788]. The differential expression of tRNA genes such as MT-TN and MT-TC has been validated using locus-specific pyrosequencing [PMC6311003]. In articular cartilage RNA-Seq data from monkeys, the expression of MT-TN is increased following a specific treatment and is involved in mitochondrial enzyme Complex 1 for protein synthesis [PMC9025840]. Various other tRNA genes are also present in mtDNA, such as MT-TL1, MT-TC, and many others [PMC8947152].