The First Complete Mitochondrial Genome of the Genus Litostrophus : Insights into the Rearrangement and Evolution of Mitochondrial Genomes in Diplopoda.

This study presents the complete mitochondrial genome (mitogenome) of Litostrophus scaber , which is the first mitogenome of the genus Litostrophus . The mitogenome is a circular molecule with a length of 15,081 bp. The proportion of adenine and thymine (A + T) was 69.25%. The gene ND4L used TGA as the initiation codon, while the other PCGs utilized ATN (A, T, G, C) as the initiation codons. More than half of the PCGs used T as an incomplete termination codon. The transcription direction of the L. scaber mitogenome matched Spirobolus bungii , in contrast to most millipedes. Novel rearrangements were found in the L. scaber mitogenome: trnQ -trnC and trnL1- trnP underwent short-distance translocations and the gene block rrnS-rrnL-ND1 moved to a position between ND4 and ND5, resulting in the formation of a novel gene order. The phylogenetic analysis showed that L. scaber is most closely related to S. bungii , followed by Narceus magnum . These findings enhance our understanding of the rearrangement and evolution of Diplopoda mitogenomes.