Characterization and Phylogenetic Analysis of the Complete Mitochondrial Genomes of Two Tiny Necrophagous Phorid Flies, Metopina sagittata and Puliciphora borinquenensis (Diptera: Phoridae)

The mitochondrial genome is frequently used for species identification and phylogenetic studies. In this study, we first sequenced and annotated the complete mitochondrial genomes of two phorid species that are forensically important in buried or enclosed environments: Metopina sagittata (Liu) and Puliciphora borinquenensis (Wheeler).The complete mitochondrial genome sequences of M. sagittata and P. borinquenensis were 15,640 bp with an A+T content of 75.97% and 15,429 bp with an A+T content of 75.38%, respectively.Their circular genomes both contained 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 control region located between rrnS and trnl which was 808 bp for M. sagittata and 746 bp for P. borinquenensis. All the PCGs of both species started with ATN codons except for cox1 which usedTTG codon. In addition to the common stop codonTAA and TAG, the incomplete stop codonT was used in two PCGs (cox1 and nad4) of M. sagittata and five PCGs (cox1, cox2, cox3, nad5, and nad4) of P. borinquenensis.There were 3 and 10 mismatched base pairs in the tRNA secondary structures from M. sagittata and P. borinquenensis, respectively. Both maximum likelihood and Bayesian inference analyses indicated that Platypezidae and Phoridae are sister taxa. M. sagittata is closely related to P. borinquenensis within the subfamily Metopininae. This work enhances the databases of Phoridae genomes and contributes to the further study of species identification and phylogenetics of this family.