Comparative Analyses Reveal Mitogenome Characteristics of Halictidae and Novel Rearrangement (Hymenoptera: Apoidea: Anthophila)

Halictidae, as a major pollinator family in bees, has significant ecological value. However, the insufficient molecular data for this group has limited our understanding of the evolutionary history of this group. Herein, we newly sequenced and assembled four mitogenomes of Halictidae, including three species of Nomiinae and one species of Rophitinae. We analyzed the characters of the newly obtained mitogenomes, including nucleotide composition, sequence length, and gene rearrangements. The length of the newly sequenced mitogenomes ranged from 16,492 to 21,192 bp, and all newly obtained mitogenomes contained 22 tRNAs, 13 protein-coding genes, two rRNAs, and one control region. Their AT content (%) ranged from 82.55 to 86.44. Relative synonymous codon usage analysis showed that UUU, UUA, and AUU were the preferred codons. The relative synonymous codon usage > 2 of mostly newly sequenced species was as follows: UUA > UCA > CGA. All newly obtained mitogenomes show gene rearrangement; we found five gene rearrangement patterns in total. Notably, ND4-trnP-ND4L-trnT was the first reported gene rearrangement pattern in bees. In addition, we reconstructed the phylogenetic relationships of Halictidae based on 10 species (eight ingroups and two outgroups), using Bayesian Inference and Maximum Likelihood approaches. Phylogenetic analysis showed that Rophitinae was the basal group within Halictidae.