Comparative Analysis of Mitogenomes of Chironomus (Diptera: Chironomidae)

Abstract

(1) Background: Chironomids are biological indicators, playing an important role in monitoring and assessing the changes in water ecosystems. Mitochondrial genomes have been widely applied as a molecular marker to analyze the taxonomy and phylogeny of insects. However, knowledge of the mitogenomes of Chironomus species is scarce at present, which limits our understanding of the evolutionary relationships among Chironomus. (2) Methods: In our study, the mitogenomes and their basic structure of 12 Chironomus species and one Microchironomus species were newly sequenced. Combined with reported mitogenomes, a total of 15 mitogenomes of Chironomus were selected for a comparative mitogenomic analysis and phylogenetic reconstruction of Chironomus. (3) Results: Each mitogenome of the Chironomus species has the typical 37 genes and a control region. The basic structure of the whole mitogenomes of Chironomus species is relatively conservative, and the genetic arrangements stay the same as the ancestral mitogenome. (4) Conclusions: Our study enriches the library of mitogenomes of chironomids and provides a valuable resource for understanding the evolutionary history of Chironomus.

New Mitogenomes of the Polypedilum Generic Complex (Diptera: Chironomidae): Characterization and Phylogenetic Implications

“…ATP8 , ND6 , and ND5 showed higher ω value, indicating that they exhibited relatively relaxed purifying selection pressure. Meanwhile, COX2 and COX3 were under the hardly purifying selection, which were similar to previous research results regarding chironomids [ 2 , 3 , 10 , 43 ].…”

“…The Ka/Ks value (ω) was usually used to measure the rate of sequence evolution by natural selection [ 45 , 46 ]. The result of Ka/Ks ratio of all 13 PCGs was less than one, ranging from 0.0958 ( COX3 ) to 0.7251 ( ATP8 ) ( Figure 3 ), which was same as other insects [ 43 , 44 ]. The evolution rate of 13 PCGs was as follows: ATP8 > ND6 > ND5 > ND3 > ND2 > ND4L > ND4 > COX1 > ND1 > CYTB > APT6 > COX2 > COX3 .…”

“…The nucleotide composition of the newly reported mitogenomes were similar ( Table 2 ), revealing the characteristic AT-biased composition in Chironomidae and other insects [ 2 , 3 , 10 , 25 , 42 , 43 , 44 ]. The AT content of the mitochondrial genomes ranged from 75.98% ( Stictochironomus akizukii ) to 79.94% ( Phaenopsectra flavipes ; Figure 2 ; Table 2 ).…”

Codon bias analysis of the mitochondrial genome reveals natural selection in the nonbiting midge Microtendipes umbrosus Freeman, 1955 (Diptera: Chironomidae)

“…Furthermore, it can enhance our understanding of the evolutionary mechanisms underlying mitochondrial gene coding. The increasing availability of Chironomidae mitochondrial genomes has been instrumental in resolving the phylogenetic relationship of this family (Li et al 2022, Zhang et al 2023). And a growing number of studies have used codon bias analysis to investigate the adaptability of chironomids to their living environment (Zheng et al 2021, Lin et al 2022).…”

New mitogenomes from the genus Cricotopus (Diptera: Chironomidae, Orthocladiinae): Characterization and phylogenetic implications

“…A dated phylogeny of Chironomidae at subfamily and lower taxonomic levels has been constructed (Cranston et al, 2012) using only four genes: two ribosomal, one nuclear and one mitochondrial gene. As an increasing number of chironomid mitogenomes are published (Fang et al, 2022, 2023; Lei et al, 2021; Li et al, 2022; Lin, Liu, et al, 2022; Lin, Zhao, et al, 2022; Qi et al, 2023; Zhang et al, 2023; Zheng et al, 2021, 2022), it is becoming possible to compare the utility of additional mitochondrial genes, or whole genomes, for phylogenetic studies of chironomids at both higher and lower taxonomic levels.…”