Comparative Mitogenomic Analysis of Two Cuckoo Bees (Apoidea: Anthophila: Megachilidae) with Phylogenetic Implications.

Abstract

Simple SummaryMegachilidae plays an important role in natural and agricultural ecosystems. There is uncertainty in the phylogenetic relationship among tribes of Megachilidae. Due to the lack of basic analysis of the mitogenomic structure of the cuckoo bees (cleptoparasitic bees) of the Megachilidae, the risk of insect cleptoparasitism in the Megachilidae is not fully understood. To further provide a new perspective on the phylogenetic relationship of Megachilidae and enrich the basic theory of cleptoparasitic controls, two mitogenomes of cuckoo bees (Coelioxys fenestrata and Euaspis polynesia) were sequenced and analyzed. Different mitogenomic structures and base compositions were found between two cuckoo bees based on comparative analyses of general characteristics of the mitochondrial, noncoding region and gene rearrangement pattern. In addition, the phylogenetic results strongly supported that the tribe-level relationship of Megachilidae was Osmiini + (Anthidiini + Megachilini). Our findings clarified the phylogenetic position among tribes from the mitogenome level so as to provide a further basis to study the evolution of Megachilidae.Bees (Hymenoptera, Apoidea and Anthophila) are distributed worldwide and considered the primary pollinators of angiosperm. Megachilidae is one of the largest families of Anthophila. In this study, two complete mitogenomes of cuckoo bees in Megachilidae, namely Coelioxys fenestrata and Euaspis polynesia, were amplified and sequenced, with a length of 17,004 bp (C. fenestrata) and 17,682 bp (E. polynesia). The obtained results show that 37 mitogenomic genes and one putative control region were conserved within Hymenoptera. Truncated stop codon T was found in the cox3 gene of E. polynesia. The secondary structure of small (rrnS) and large (rrnL) rRNA subunits contained three domains (28 helices) and five domains (44 helices) conserved within Hymenoptera, respectively. Compared with ancestral gene order, gene rearrangement events included local inversion and gene shuffling. In order to reveal the phylogenetic position of cuckoo bees, we performed phylogenetic analysis. The results supported that all families of Anthophila were monophyletic, the tribe-level relationship of Megachilidae was Osmiini + (Anthidiini + Megachilini) and Coelioxys fenestrata was clustered to the Megachile genus, which was more closely related to Megachile sculpturalis and Megachile strupigera than Euaspis polynesia.