Macrostructural Evolution of the Mitogenome of Butterflies (Lepidoptera, Papilionoidea)

Simple Summary Papilionoidea is a superfamily of Lepidoptera encompassing about 19,000 species. In the present work, we study the evolution of the structure of the mitogenome of these lepidopterans. The mechanisms generating the eight arrangements known for Papilionoidea were investigated analysing the movements of different mitochondrial genes. Five newly sequenced/assembled mitogenomes were included in our analysis involving more than 600 genomes. We provide new findings that help to understand the evolution of the gene orders MIQGO, IMQGO, 2S1GO, ES1GO and S1NGO in different butterflies. We demonstrate that the evolution of the 2S1GO in Lycaenidae followed a complicated pathway with multiple events of duplication and loss of trnS1 and changes in anticodon. We describe two new gene orders 2FFGO and 4QGO for Ampittia subvittatus (Hesperiidae) and Bhutanitis thaidina (Papilionidae). The mitogenome of the species belonging to the Papilionodea (Lepidoptera) is a double stranded circular molecule containing the 37 genes shared by Metazoa. Eight mitochondrial gene orders are known in the Papilionoidea. MIQGO is the plesiomorphic gene order for this superfamily, while other mitochondrial arrangements have a very limited distribution. 2S1GO gene order is an exception and is present in several Lycaenidae and one species of Hesperiidae. We studied the macrostructural changes generating the gene orders of butterflies by analysing a large data set (611 taxa) containing 5 new mitochondrial sequences/assemblies and 87 de novo annotated mitogenomes. Our analysis supports a possible origin of the intergenic spacer trnQ-nad2, characterising MIQGO, from trnM. We showed that the homoplasious gene order IMQGO, shared by butterflies, species of ants, beetles and aphids, evolved through different transformational pathways. We identify a complicated evolutionary scenario for 2S1GO in Lycaenidae, characterised by multiple events of duplication/loss and change in anticodon of trnS1. We show that the gene orders ES1GO and S1NGO originated through a tandem duplication random loss mechanism. We describe two novel gene orders. Ampittia subvittatus (Hesperiidae) exhibits the gene order 2FFGO, characterised by two copies of trnF, one located in the canonical position and a second placed in the opposite strand between trnR and trnN. Bhutanitis thaidina (Papilionidae) exhibits the gene order 4QGO, characterised by the quadruplication of trnQ.