Complete Mitochondrial Genome Sequence Research Articles

Characterization of the complete mitochondrial genome of Paecilomyces variotii and comparative evolutionary mitochondriomics of 36 fungi.

Paecilomyces variotii has important economic value in stimulating crop growth, biodegradation, and other aspects. Up to now, there are no research reports on its mitochondrial genome. The mitochondrial genome of Paecilomyces variotii was determined with the next-generation sequencing method (Illumina, NovaSeq), and its characteristics were analyzed using various bioinformatics approaches. The length of complete mitochondrial genome sequence of P. variotii is 40,965bp and consists of 14 protein-coding genes, 2 ribosomal RNA genes, 1 ribosomal protein S3 gene, 26 transport RNA genes. The results of phylogenetics analysis using Bayesian inference and Maximum likelihood methods showed that P. variotii belongs to the Eurotiales order in the Thermoascaceae family, and 9 genera within the Eurotiomycetes class were effectively distinguished with high support rates (bootstrap value > 92% and posterior probabilities > 99%). The analysis of synonymous substitution rates and nonsynonymous substitution rates indicated that the Ka/Ks values of the 14 PCGs in the mitochondrial genomes of the two orders in the Eurotiomycetes class ranged from 0 to 0.4333. This study revealed the structural and sequence information characteristics of the mitochondrial genome of P. variotii, and the phylogenetic results strongly support its classification within the family Thermoascaceae, consistent with traditional morphological taxonomy studies. The 14 PCGs in the mitochondrial genomes of the two orders in the Eurotiomycetes class are subject to strong purifying (negative) selection. The results of this research provides an important molecular basis for the development of genomics, evolutionary genetics and molecular markers of P. variotii in the future.

Comparative Analysis and Phylogenetic Study of Dawkinsia filamentosa and Pethia nigrofasciata Mitochondrial Genomes.

Smiliogastrinae are recognized for their high nutritional and ornamental value. In this study, we employed high-throughput sequencing technology to acquire the complete mitochondrial genome sequences of Dawkinsia filamentosa and Pethia nigrofasciata. The gene composition and arrangement order in these species were similar to those of typical vertebrates, comprising 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 non-coding region. The mitochondrial genomes of D. filamentosa and P. nigrofasciata measure 16,598 and 16,948 bp, respectively. Both D. filamentosa and P. nigrofasciata exhibit a significant preference for AT bases and an anti-G bias. Notably, the AT and GC skew values of the ND6 gene fluctuated markedly, suggesting that the selection and mutation pressures on this gene may differ from those affecting other genes. Phylogenetic analysis, based on the complete mitochondrial genomes of 23 Cyprinidae fishes, revealed that D. filamentosa is closely related to the sister group comprising Dawkinsia denisonii and Sahyadria chalakkudiensis. Similarly, P. nigrofasciata forms a sister group with Pethia ticto and Pethia stoliczkana.

The complete mitochondrial genome of Tauraco livingstonii (Musophagidae: Tauraco)

Livingstone’s turaco, Tauraco livingstonii, belongs to the family Musophagidae. In this study, we obtained the complete mitochondrial genome sequence of Livingstone’s turaco by high-throughput sequencing technology and constructed a phylogenetic tree. It was found that the mitochondria of this species are 19,015 bp in length and contain a total of 37 genes, comprising 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes. The base composition of the mitochondrial genome is 31.61% A, 24.22% T, 30.64% C, and 13.52% G, with a GC content of 44%. Notably, an intriguing phenomenon of mitochondrial genome rearrangements was observed, characterized by the duplication of the tRNA Glu-L-CR gene order. In addition, the results of the phylogenetic tree analysis shed light on the taxonomic position of Livingstone’s turaco and supported the taxonomy of Otidimorphae. The study provides a basis for future phylogenetic and taxonomic investigations of Musophagiformes.

Complete mitochondrial genome of Basilepta melanopus Lefèvre, 1893 (coleoptera: chrysomelidae: eumolpinae), a tea pest from Southern China

The tea pest, Basilepta melanopus Lefèvre 1893 (Chrysomelidae), belongs to the subfamily Eumolpinae. In this study, the complete mitochondrial genome sequence of B. melanopus from southern China was sequenced using the next-generation sequencing technique, assembled, and annotated using bioinformatics tools. The complete mitochondrial genome was 15,905 bp in length. The overall GC content was 22.51%, in which the percentages for the bases A, T, C, and G were 41.23%, 36.26%, 8.92%, and 13.59%, respectively. Thirty-seven genes were predicted, including 13 protein-coding, 22 transfer RNA, and two ribosomal RNA genes. Phylogenetic analysis based on the complete mitochondrial genome sequences of 18 Chrysomelidae taxa revealed that B. melanopus was closely related to Basilepta fulvipes.

Comparative Analysis of Mitochondrial Genome in Fishes

Mitochondrial genome is circular double stranded DNA molecule in most of the eukaryotic organism which is ubiquitously present in all cells as it associated with production of energy. The number of complete mitochondrial genomes sequenced has been increasing day by day. Till date, the complete mitochondrial genome more than 2000 fish species can be retrieved from the NCBI GenBank. Like other vertebrates, fish mitochondrial genome contains 37 genes which include 22 tRNAs, 2 rRNAs (12S & 16S), 13 protein coding genes and one noncoding regions (Control region). The length of fish mitochondrial genome varies based on the size of noncoding region (CR). The complete mitochondrial genome sequence length varies from species to species. This comparison of genome sequences envisage the variations are mostly in the control region as it is highly evolved than other genes of mitochondria. Its mutation rate is very high. Therefore more numbers of indels and intergenic sequences are found. It may be due to the genetic drift, relaxed functional constraint and reduced selection pressure in the evolution of fish mitogenomes.

Climate-driven mitochondrial selection in lacertid lizards.

The mitochondrion, which is an intracellular organelle responsible for most of the energy-producing pathways, can have its genome targeted for climate-driven selection. However, climate-driven mitochondrial selection remains a sparsely studied area in reptiles. Here, we reported the complete mitochondrial genome sequence of a lacertid lizard (Takydromus intermedius) and used mitogenomes from 54 species of lacertid lizards to study their phylogenetic relationships and to identify the mitochondrial genes under positive selection by climate. The length of the complete mitochondrial genome sequence of T. intermedius was 17,713 bp, which was within the range of lengths (17,224-18,943) ever reported for Takydromus species. The arrangement of mitochondrial genes in T. intermedius was the same as in other congeneric species. The 54 lacertid species could be divided into three geographically and climatically different clades. We identified three mitochondrial genes (ATP6, ATP8, and ND3) under positive selection by climate, and found that isothermality, temperature seasonality, precipitation of wettest month, and precipitation seasonality were the most important climatic variables contributing to the gene selection.

Analysis of the mitochondrial genome and phylogenetic relationships of Mong chicken

In this study, the complete nucleotide sequence of the mitochondrial genome of the Mong chicken and an indigenous chicken breed of Vietnam, was determined by the Sanger sequencing method, structurally analysed and used to evaluate the phylogenetic relationship with different chicken breeds. The complete nucleotide sequence data of the Mong chicken’ mitochondrial genome was registered on GenBank with the accession number OR643716. The Mong chicken’ mitochondrial genome has a size of 16785 base pair (bp) and includes 22 transfer RNA genes, two ribosomal RNA genes, 13 protein-coding genes, and one non-coding control region (D-loop). A, T, G, and C nucleotide proportions were 30.28, 23.76, 13.48, and 32.48%, respectively. Results of the analysis of phylogenetic relationships based on 33 complete mitochondrial genome sequences showed that the Mong chicken has evolutional origin from the red junglefowl subspecies Gallus gallus spadiceus. The Mong chicken is in close relationship with the Dong Tao chicken and Cao Son dwarf chicken in Vietnam, Rugao yellow chicken and Xiaoxiang chicken in China.

Mitogenomic evidence of population differentiation of thorny skate, Amblyraja radiata, in the North Atlantic.

Management of thorny skate (Amblyraja radiata) in the Northwest Atlantic has posed a conservation dilemma for several decades due to the species' lack of response to strong conservation efforts in the US Gulf of Maine and the Canadian Scotian Shelf, confusion over the relationship between two reproductive size morphs of differing life histories that are sympatric in the Northwest Atlantic, and conflicting data on regional population connectivity throughout the species' broader range. To better assess potential A. radiata regional population differentiation and genetic links to life-history variation, we analysed complete mitochondrial genome sequences from 527 specimens collected across the species' North Atlantic geographic range, with particular emphasis on the Northwest Atlantic region. A high level of genetic diversity was evident across the North Atlantic, but significant genetic differentiation was identified between specimens inhabiting the Northwest (Gulf of Maine and Newfoundland) and Northeast (Greenland, Iceland, North Sea, and Arctic Circle) Atlantic. In the Northwest Atlantic, significant differentiation between the Gulf of Maine and Newfoundland regions was revealed; however, the overall level of differentiation was very low. No genetic difference was identified between the large and small reproductive morphs. The results of this study advance our understanding of A. radiata population structure in the North Atlantic but do not resolve all the questions confounding our understanding of the species' biology and evolutionary history.

The complete mitochondrial genome of Poraniopsis inflata (Asteroidea: Valvatida: Poraniidae) from Dokdo Island, Korea

This study presents the complete mitochondrial genome sequence of Poraniopsis inflata, providing valuable information on its genetic and taxonomic studies. Through next-generation sequencing, we successfully obtained the complete mitogenome of P. inflata, spanning a length of 16,322 bp. This genome structure encompasses 13 protein-coding genes (PCGs), 22 transfer RNA genes, and two ribosomal RNA genes. The phylogenetic analysis, based on a dataset of 13 PCG sequences, illuminated the phylogenetic relationships of P. inflata with other species of class Asteroidea and a species of echinoderm classes. The maximum likelihood phylogenetic tree showed that P. inflata closely clustered with Linckia laevigata. By revealing its mitochondrial genome and positioning it within the Asteroidea lineage, this study provides insights into the phylogenetic context of P. inflata.

The complete mitochondrial genome of Gobio huanghensis (Cypriniformes: Cyprinidae) in the Yellow River, China

Gobio huanghensis, a member of the eponymous genus within the Cyprinidae, family of the Cypriniformes order, is an endemic fish species found exclusively in the upper reaches of the Yellow River, spanning from Yinchuan to Lanzhou. This study presents the first comprehensive report of the complete mitochondrial genome sequence of G. huanghensis, encompassing 16,604 base pairs (bp) with a nucleotide composition of 26.3% cytosine (C), 17.6% guanine (G), 29.4% adenine (A), and 26.7% thymine (T). In congruence with other species in the Gobio genus, its mitochondrial genome comprises 37 genes, including two ribosomal RNA genes, 13 protein-coding genes (PCGs), and 22 transfer RNA genes. Notably, COX1 initiates with the start codon GTG, distinct from the typical ATG start codon of other PCGs. The mitogenome exhibits four types of stop codons: TAA, TAG, TA-, and T--. Phylogenetic analyses, grounded in complete mitochondrial sequences, position G. huanghensis at the forefront of one of two major clusters within the genus Gobio, corroborating existing morphological classifications. These findings offer valuable theoretical insights for the taxonomic classification, conservation, and population genetics of G. huanghensis.

The complete mitochondrial genome of the tropical sea urchin Tripneustes gratilla (Linnaeus, 1758) with two spine colors

The complete mitochondrial genomes of two spine-color individuals, red and white, of the tropical sea urchin species Tripneustes gratilla (Linnaeus, 1758) were sequenced on Illumina system platform. The red-spined species had a genome size of 15,774 bp, while the white-spined species had a genome size of 15,723 bp. Both genomes contained 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. The GC composition in both species was above 40%. In order to investigate the phylogenetic relationships of two different spine-color individuals, a comprehensive analysis was conducted using eight complete mitochondrial genomic sequences of the genus Tripneustes on the software MEGA X. It was observed that the two spine color types of T. gratilla species showed a high similarity of 98.91%. However, different color-spined species of T. gratilla were found in separate branches of the phylogenetic tree of the same sea urchin species.

Structural Analysis and Phylogenetic Relationship of a Lepidopteran Scopelodes kwangtungensis Based on its Complete Mitochondrial Genome Sequence

Structural Analysis and Phylogenetic Relationship of a Lepidopteran Scopelodes kwangtungensis Based on its Complete Mitochondrial Genome Sequence

The complete mitochondrial genome and phylogenetic analysis of hydrozoan jellyfish Eirene ceylonensis (Cnidaria, Hydrozoa, Eirenidae) in the coastal sea of Qinhuangdao, China

Eirene ceylonensis, a hydrozoan jellyfish species with a complex polymorphic life cycle, is widely distributed in the Chinese coastal sea. In this study, we conducted sequencing and analysis of the first complete mitochondrial genome of E. ceylonensis, obtained from the coastal sea of Qinhuangdao, China. The linear mitochondrial genome is 14,997 bp in length with the overall AT content being 72.8%, encoding 13 protein-coding genes (PCGs), two transfer RNA (tRNA) genes (tRNA-Met and tRNA-Trp) and two ribosomal RNA (rRNA) genes (rrnS and rrnL). Phylogenetic analysis of 13 PCGs suggests that the E. ceylonensis is closely related to Laomedea flexuosa. The availability of the complete mitochondrial genome of E. ceylonensis will be useful for studying the evolutionary relationships of hydrozoan jellyfish species.

The complete mitochondrial genome of the Kandelia obovata Sheue, H.Y.Liu & J.W.H.Yong (Rhizophoraceae)

Kandelia obovata Sheue, H.Y.Liu & J.W.H.Yong is one of the most cold-resistant true mangrove species, and it is widely distributed from the South China Sea to southern Japan. In the current study, the complete mitochondrial genome sequence of K. obovata was assembled using Illumina reads. It is the first mitochondrial genome of the Kandelia genus within the family Rhizophoraceae to be sequenced. The mitochondrial genome size is 312,146 bp with a total of 49 predicted genes, including 29 protein-coding genes, 17 transfer RNA genes, and 3 ribosomal RNA genes. The overall GC content of the genome is 41.87%. A phylogenetic tree constructed using nine complete mitochondrial genomes revealed that K. obovata is more closely related to Bruguiera species. This study enriches the plastid genome of Kandelia, furnishing valuable genetic insights for the investigation of evolutionary and population genetics in Kandelia and other mangrove species.

Anopheles gambiae on remote islands in the Indian Ocean: origins and prospects for malaria elimination by genetic modification of extant populations

The mosquito Anopheles gambiae s.s. is a primary malaria vector throughout sub-Saharan Africa including the islands of the Comoros archipelago (Anjouan, Grande Comore, Mayotte and Mohéli). These islands are located at the northern end of the Mozambique Channel in eastern Africa. Previous studies have shown a relatively high degree of genetic isolation between the Comoros islands and mainland populations of A. gambiae, but the origin of the island populations remains unclear. Here, we analyzed phylogenetic relationships among island and mainland populations using complete mitochondrial genome sequences of individual A. gambiae specimens. This work augments earlier studies based on analysis of the nuclear genome. We investigated the source population of A. gambiae for each island, estimated the number of introductions, when they occurred and explored evidence for contemporary gene flow between island and mainland populations. These studies are relevant to understanding historical patterns in the dispersal of this important malaria vector and provide information critical to assessing their potential for the exploration of genetic-based vector control methods to eliminate this disease. Phylogenetic analysis and haplotype networks were constructed from mitogenome sequences of 258 A. gambiae from the four islands. In addition, 112 individuals from seven countries across sub-Saharan Africa and Madagascar were included to identify potential source populations. Our results suggest that introduction events of A. gambiae into the Comoros archipelago were rare and recent events and support earlier claims that gene flow between the mainland and these islands is limited. This study is concordant with earlier work suggesting the suitability of these oceanic islands as appropriate sites for conducting field trial releases of genetically engineered mosquitoes (GEMs).

Assembly and analysis of the complete mitochondrial genome of Forsythia suspensa (Thunb.) Vahl

BackgroundForsythia suspensa (Thunb.) Vahl is a valuable ornamental and medicinal plant. Although the nuclear and chloroplast genomes of F. suspensa have been published, its complete mitochondrial genome sequence has yet to be reported. In this study, the genomic DNA of F. suspensa yellowish leaf material was extracted, sequenced by using a mixture of Illumina Novaseq6000 short reads and Oxford Nanopore PromethION long reads, and the sequencing data were assembled and annotated.ResultThe F. suspensa mitochondrial genome was obtained in the length of 535,692 bp with a circular structure, and the GC content was 44.90%. The genome contains 60 genes, including 36 protein-coding genes, 21 tRNA genes, and three rRNA genes. We further analyzed RNA editing of the protein-coding genes, relative synonymous codon usage, and sequence repeats based on the genomic data. There were 25 homologous sequences between F. suspensa mitochondria and chloroplast genome, which involved the transfer of 8 mitochondrial genes, and 9473 homologous sequences between mitochondrial and nuclear genomes. Analysis of the nucleic acid substitution rate, nucleic acid diversity, and collinearity of protein-coding genes of the F. suspensa mitochondrial genome revealed that the majority of genes may have undergone purifying selection, exhibiting a slower rate of evolution and a relatively conserved structure. Analysis of the phylogenetic relationships among different species revealed that F. suspensa was most closely related to Olea europaea subsp. Europaea.ConclusionIn this study, we sequenced, assembled, and annotated a high-quality F. suspensa mitochondrial genome. The results of this study will enrich the mitochondrial genome data of Forsythia, lay a foundation for the phylogenetic development of Forsythia, and promote the evolutionary analysis of Oleaceae species.

The New Mitochondrial Genome of Hemiculterella wui (Cypriniformes, Xenocyprididae): Sequence, Structure, and Phylogenetic Analyses.

Hemiculterella wui is an endemic small freshwater fish, distributed in the Pearl River system and Qiantang River, China. In this study, we identified and annotated the complete mitochondrial genome sequence of H. wui. The mitochondrial genome was 16,619 bp in length and contained 13 protein coding genes (PCGs), two rRNA genes, 22 tRNA genes, and one control region. The nucleotide composition of the mitochondrial genome was 29.9% A, 25.3% T, 27.4% C, and 17.5% G, respectively. Most PCGs used the ATG start codon, except COI and ATPase 8 started with the GTG start codon. Five PCGs used the TAA termination codon and ATPase 8 ended with the TAG stop codon, and the remaining seven genes used two incomplete stop codons (T and TA). Most of the tRNA genes showed classical cloverleaf secondary structures, except that tRNASer(AGY) lacked the dihydrouracil loop. The average Ka/Ks value of the ATPase 8 gene was the highest, while the average Ka/Ks value of the COI gene was the lowest. Phylogenetic analyses showed that H. wui has a very close relationship with Pseudohemiculter dispar and H. sauvagei. This study will provide a valuable basis for further studies of taxonomy and phylogenetic analyses in H. wui and Xenocyprididae.

Complete mitochondrial genome analyses confirm that bat Polychromophilus and ungulate Plasmodium constitute a distinct clade independent of other Plasmodium species

In recent phylogenetic studies, bat Polychromophilus and ungulate Plasmodium, two relatively understudied haemosporidian parasites within the Apicomplexa phylum, have often been overlooked. Instead, the focus has been primarily on haemosporidian parasites in primates, rodents, and birds. Several phylogenetic analyses of bat Polychromophilus have relied on limited datasets and short informative DNA sequences. As a result of these inherent limitations, the substantiation of their evolutionary stance has encountered a diminished degree of robust validation. This study successfully obtained complete mitochondrial genome sequences from 11 Polychromophilus parasites originating from Hipposideros gentilis and Myotis siligoensis bats for the first time. Additionally, the authors have sequenced the apicoplast caseinolytic protease C genes from Polychromophilus murinus and a potentially new Polychromophilus species. These mitochondrial genomes range in length from 5994 to 6001 bp and consist of three protein-coding genes (PCGs), seven small subunit ribosomal RNA genes (SSU rRNA), 12 large subunit ribosomal RNA genes (LSU rRNA), and seven miscellaneous RNA genes. Phylogenetic analyses using Bayesian Inference and Maximum Likelihood methods indicated robust support for the grouping of ungulate Plasmodium and bat Polychromophilus in a single clade separate from other Plasmodium spp., confirming previous reports, albeit with stronger evidence in this study. The divergence between Polychromophilus in bats and Plasmodium in ungulates occurred approximately 29.61 to 55.77 million years ago (Mya), with a node age estimated at 40.63 Mya. These findings highlight that the genus Plasmodium, which includes species found in ungulates, birds, reptiles, and other mammals, does not form a monophyletic group. By incorporating Polychromophilus in bats and Plasmodium in ungulates, this study contributes significantly to understanding the phylogenetic relationships within the Haemosporida order. It provides valuable insights into the evolutionary history and interconnections among these diverse parasites, thereby expanding knowledge in this field.

Characterization of the CMS genetic regulation through comparative complete mitochondrial genome sequencing in Nicotiana tabacum.

Mitochondrial genomes (mitogenomes) of flowering plants vary greatly in structure and size, which can lead to frequent gene mutation, rearrangement, or recombination, then result in the cytoplasmic male sterile (CMS) mutants. In tobacco (Nicotiana tabacum), suaCMS lines are widely used in heterosis breeding; however, the related genetic regulations are not very clear. In this study, the cytological observation indicated that the pollen abortion of tobacco suaCMS(HD) occurred at the very early stage of the stamen primordia differentiation. In this study, the complete mitochondrial genomes of suaCMS(HD) and its maintainer HD were sequenced using the PacBio and Illumina Hiseq technology. The total length of the assembled mitogenomes of suaCMS(HD) and HD was 494,317bp and 430,694bp, respectively. Comparative analysis indicated that the expanded 64 K bases in suaCMS(HD) were mainly located in noncoding regions, and 23 and 21 big syntenic blocks (>5000bp) were found in suaCMS(HD) and HD with a series of repeats. Electron transport chain-related genes were highly conserved in two mitogenomes, except five genes (ATP4, ATP6, COX2, CcmFC, and SDH3) with substantial substitutions. Three suaCMS(HD)-specific genes, orf261, orf291, and orf433, were screened. Sequence analysis and RT-PCR verification showed that they were unique to suaCMS(HD). Further gene location analysis and protein property prediction indicated that all the three genes were likely candidates for suaCMS(HD). This study provides new insight into understanding the suaCMS mechanism and is useful for improving tobacco breeding.

On the Species Identification of Korean Geoduck Clam (Panopea sp. 1) Based on the Morphological and Molecular Evidence

The geoduck clam is a high-value species in South Korea. However, the molecular and morphological characteristics of geoduck clams from the southern coast of South Korea remain unexamined. The accurate identification of native geoduck clams is crucial for their conservation and management. Therefore, this study used a combination of molecular and morphological analyses to characterize native geoduck clams from the southern coast of South Korea. Based on complete mitochondrial genome and morphological analyses, the native species of geoduck clam from this study area was identified as Panopea sp. 1. The complete mitochondrial genome sequencing of Panopea sp. 1 revealed a total of 16,225 bp in length with 37 genes (13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes). It was also shown that Panopea sp. 1 belongs to the family Hiatellidae based on a phylogenetic analysis tree with 11 bivalve species. In particular, Panopea sp. 1 is closely related to three other Panopea species (Panopea sp., Panopea abrupta, and Panopea japonica). The phylogenetic analysis correlated with the morphological analysis. Overall, this is the first reliable record of Panopea sp. 1 in South Korea. These findings provide a basis for accurate species identification based on morphological characteristics and complete mitochondrial genome sequencing.