Comparative Mitogenome Analyses of Subgenera and Species Groups in Epeorus (Ephemeroptera: Heptageniidae)

Abstract

Epeorus Eaton, 1881 is a diverse mayfly genus in Heptageniidae comprising more than 100 species which are further divided into nine subgenera and several species groups. However, the classification and the phylogenetic relationships among them are still uncertain. Here, 15 complete mitochondrial genomes of Epeorus were sequenced and compared together with six available ones of same genus in the NCBI database. Based on morphological classification, the 21 mitogenomes were classified into six subgenera (Proepeorus, Epeorus s.str., Belovius, Iron, Caucasiron and Siniron) and four species groups (G1, G2, montanus and longimanus). Among all analyzed mitogenomes, the gene rearrangement of trnI-trnM-trnQ-NCR-ND2 was first found occurring in three species of group G1, whereas the gene block trnI-trnM-trnQ-trnM-ND2 was observed in all other mitogenomes of Epeorus. Furthermore, the genetic composition and codon usage of species in group G1 were also significantly different from all other Epeorus species, except group longimanus. The intergenic spacer between trnA and trnR, which has the stem-loop secondary structure, occurred in all 21 mitogenomes, and the sequences of stems and loops were conserved within species groups. Furthermore, the phylogenetic analyses strongly support the monophyly of all species groups, although three of six recognized subgenera Proepeorus, Belovius, and Iron, were shown as the non-monophyletic groups.

Comparative Analysis of Mitogenomes of Chironomus (Diptera: Chironomidae)

“…The mitochondrial genome (mitogenome) of insects is a 14-20 kb circular molecule, including 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and one non-coding control region (CR) [1]. Mitogenomes are considered as useful molecular markers for phylogenetic and evolutionary analysis in many insect groups [2][3][4][5] Insects 2022, 13, 1164 2 of 11 due to their small genome size, maternal inheritance, low sequence recombination, and fast evolutionary rates [6,7]. With the wide application of the high-throughput sequencing technology, mitogenomes have proven successful in species delimitation and phylogenetics among aquatic insects [4,5,[8][9][10][11][12][13][14][15].…”

Comparative Mitogenome of Phylogenetic Relationships and Divergence Time Analysis within Potamanthidae (Insecta: Ephemeroptera)

“…Eighty mt genomes were used for phylogenetic relationship analyses, including the 7 mt genomes newly reported in this paper, and 73 mt genomes downloaded from the NCBI for Ephemeroptera in 15 families (Baetidae, Heptageniidae, Neoephemeridae, Leptophlebiidae, Isonychiidae, Ephemerellidae, Ephemeridae, Viemamellidae, Potamanthidae, Caenidae, Siphluriscidae, Polymitarcyidae, Ameletidae, Siphlonuridae, and Teloganodidae) [26,43,51,[70][71][72][73][74][75][76][77][78][79][80][81][82][83]. Siphluriscidae is typically regarded as occupying a basal position within the Ephemeroptera [82,84].…”

New data on mitogenomes of Thienemanniella Kieffer, 1911 (Diptera: Chironomidae, Orthocladiinae)

“…The typical mitochondrial genome (mitogenome) of insects is a double‐stranded circular molecule ranging from 14 to 20 kb in size, encoding 13 protein‐coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a control region (CR) (Brown, 1985). Because of its small genome size, maternal inheritance, low sequence recombination and fast evolutionary rate, the mitogenome is considered as a powerful marker for molecular identification and phylogenetic analysis at different taxonomic levels in Diptera, especially for Chironomidae (Ge et al, 2022; Li et al, 2020; Lin et al, 2022; Ma et al, 2022; Qi et al, 2022; Yan et al, 2019; Zhang et al, 2023; Zheng et al, 2022). Based on published mitogenome data of Chironomids, it can be seen that the mitochondrial gene order is very compact and conservative.…”