Precise annotation of Drosophila mitochondrial genomes leads to insights into AT-rich regions

In the present study, we performed precise annotation of Drosophila melanogaster , D. simulans , D. grimshawi , Bactrocera oleae mitochondrial (mt) genomes by pan RNA-seq analysis. Our new annotations corrected or modified some of the previous annotations and two important findings were reported for the first time, including the discovery of the conserved polyA(+) and polyA(−) motifs in the control regions (CRs) of insect mt genomes and the adding of CCAs to the 3’ ends of two antisense tRNAs in D. melanogaster mt genome. Using PacBio cDNA-seq data from D. simulans , we precisely annotated the Transcription Initiation Sites (TISs) of the mt Heavy and Light strands in Drosophila mt genomes and reported that the polyA(+) and polyA(−) motifs in the CRs are associated with TISs. The discovery of the conserved polyA(+) and polyA(−) motifs provides insights into many polyA and polyT sequences in CRs of insect mt genomes, leading to reveal the mt transcription and its regulation in invertebrates. In addition, we provided a high-quality, well-curated and precisely annotated D. simulans mt genome (GenBank: [MN611461][1]), which should be included into the NCBI RefSeq database to replace the current reference genome [NC_005781][2]. ### Competing Interest Statement The authors have declared no competing interest. [1]: /lookup/external-ref?link_type=GEN&access_num=MN611461&atom=%2Fbiorxiv%2Fearly%2F2021%2F06%2F07%2F2021.06.05.447193.atom [2]: /lookup/external-ref?link_type=GEN&access_num=NC_005781&atom=%2Fbiorxiv%2Fearly%2F2021%2F06%2F07%2F2021.06.05.447193.atom