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Background: Asparagus L., widely distributed in the old world is a genus under Asparagaceae, Asparagales. The species of the genus were mainly used as vegetables, traditional medicines as well as ornamental plants. However, the evolution and functions of mitochondrial (Mt) genomes (mitogenomes) remains largely unknown. In this study, the typical herbal medicine A. taliensis and ornamental plant A. setaceus were used to assemble and annotate the mitogenomes, and the resulting mitogenomes were further compared with published mitogenome of A. officinalis for the analysis of their functions in the context of domestication and adaptative evolution. Results: The mitochondrial genomes of both A. taliensis and A. setaceus were assembled as complete circular ones. The phylogenetic trees based on conserved protein-coding genes of Mt genomes and whole chloroplast (Cp) genomes showed that, the phylogenetic relationship of the sampled 13 species of Asparagus L. were not exactly consistent. The collinear analyses between the nuclear (Nu) and Mt genomes confirmed the existence of mutual horizontal genes transfers (HGTs) between Nu and Mt genomes within these species. Based on RNAseq data, the Mt RNA editing were predicted and atp1 and ccmB RNA editing of A. taliensis were further confirmed by DNA sequencing. Simultaneously homologous search found 5 Nu coding gene families including pentatricopeptide-repeats (PPRs) involved in Mt RNA editing. Finally, the Mt genome variations, gene expressions and mutual HGTs between Nu and Mt were detected with correlation to the growth and developmental phenotypes respectively. The results suggest that, both Mt and Nu genomes co-evolved and maintained the Mt organella replication and energy production through TCA and oxidative phosphorylation. Conclusion: The assembled and annotated complete mitogenomes of both A. taliensis and A. setaceus provide valuable information for their phylogeny and concerted action of Nu and Mt genomes to maintain the energy production system of Asparagus L. in the context of domestication and adaptation to environmental niches. Highlights: Mitochondrial genomes of A. taliensis and A. setaceus were assembled and annotated, and phylogenetic trees of 13 sampled species in the genus Asparagus based on both mitochondrial and chloroplast genomes showed that A. officinalis, A. taliensis and A. setaceus are represented species of Asparagus L. Independent horizontal gene transfers (HGTs) between the mitochondrial and nuclear genomes were detected with reduction in dioecious species, while Mt RNA editing rate was higher in dioecious species with consistency of their higher copies and higher expression levels of involved nuclear coding RNA editing enzyme genes. Detected different gene copies and expression levels of both pathways of tricarboxylic acid cycle(TCA) and oxidative phosphorylation genes indicates the different efficiency of citric acid accumulation and ATP synthesis due to adaptation and/or domestication among species of A. officinalis, A. taliensis and A. setaceus. [ABSTRACT FROM AUTHOR]

Introduction: Among cultivated tea plants (Camellia sinensis), only four mitogenomes for C. sinensis var. assamica (CSA) have been reported so far but none for C. sinensis var. sinensis (CSS). Here, two mitogenomes of CSS (CSSDHP and CSSRG) have been sequenced and assembled. Methods: Using a combination of Illumina and Nanopore data for the first time. Comparison between CSS and CSA mitogenomes revealed a huge heterogeneity. Results: The number of the repetitive sequences was proportional to the mitogenome size and the repetitive sequences dominated the intracellular gene transfer segments (accounting for 88.7%- 92.8% of the total length). Predictive RNA editing analysis revealed that there might be significant editing in NADH dehydrogenase subunit transcripts. Codon preference analysis showed a tendency to favor A/T bases and T was used more frequently at the third base of the codon. ENc plots analysis showed that the natural selection play an important role in shaping the codon usage bias, and Ka/Ks ratios analysis indicated Nad1 and Sdh3 genes may have undergone positive selection. Further, phylogenetic analysis shows that six C. sinensis clustered together, with the CSA and CSS forming two distinct branches, suggesting two different evolutionary pathway. Discussion: Altogether, this investigation provided an insight into evolution and phylogeny relationship of C. sinensis mitogenome, thereby enhancing comprehension of the evolutionary patterns within C. sinensis species. [ABSTRACT FROM AUTHOR]

Background: A new Liobagrus fish was reported from the Korean Peninsula, but research on this taxon is lacking. Moreover, existing research on the mitogenome of the genus Liobagrus in Korea is very limited, and no studies have been conducted on structural characteristics of transfer RNA (tRNA) or gene order comparisons between taxa; instead, research has been restricted to basic phylogeny. Objective: The complete mitochondrial genome of Liobagrus geumgangensis was analyzed for the first time. We then aimed to reconstruct the phylogenetic relationships of the genus Liobagrus and estimate the divergence time of speciation events. Methods: We used a dissected fin clip from an adult of Liobagrus geumgangensis. Genomic DNA was extracted and analyzed with whole genome sequencing (WGS) and assembled by the NOVOPlasty method. The mitogenome sequence was annotated, and a genome map, tRNA structure, and phylogenetic tree were constructed using maximum likelihood analysis. In addition, divergence time was estimated. Results: The mitochondrial genome was 16,522 bp in length and comprised 37 genes. The overall base composition was 30.5% A, 25.5% T, 28.4% C, and 15.7% G. Most tRNAs exhibited the typical clover leaf shape, except trnS1. Phylogenetic analysis revealed that Liobagrus geumgangensis clustered within a clade with four other Liobagrus species exclusive to the southern region of the Korean Peninsula. Its divergence was estimated to have occurred during the late Miocene. Conclusion: Characteristics of Liobagrus geumgangensis mitogenome were consistent with those of other torrent catfish species. Time scale estimation revealed distinct groupings, with some distributed across mainland Asia and others in the southern region of the Korean Peninsula. Notably, the Korean Peninsula group was identified as its own lineage, comprising entirely endemic species. [ABSTRACT FROM AUTHOR]

Background: The Muricidae family in the Class Gastropoda comprises numerous species with a vast range of morphological features and a worldwide presence. The phylogeny of the Muricidae has been analyzed in previous studies; however, the evolutionary relationships among the main branches of the Muricidae remain unknown. Methods and results: In the present study, the mitochondrial genome of Mancinella alouina was sequenced. The mitochondrial genome was found to be 16,671 bp in length and made up of 37 genes (13 protein-coding genes, 22 transfer RNA and 2 ribosomal RNA genes). The genome has an A-T-rich region (66.5% A + T content) and all of the PCGs use the ATN start codon and the TAG or TAA stop codons. The mitochondrial gene arrangement of Mancinella alouina is similar to that of other Muricidae, except for Ocinebrellus inornatus and Ceratostoma burnetti. On the basis of a flexible molecular clock model, time-calibrated phylogenetic results indicate that the genus Mancinella diverged roughly 18.09 Mya, and that the family Muricidae emerged in the Late Cretaceous. Conclusions: This study reveals the structural and sequence information features of the mitochondrial genome of Mancinella alouina. This study provides evidence for the relationships within the family Muricidae at the molecular level, and infer the divergence time. The results of phylogenetic analyses strongly support the current classification. [ABSTRACT FROM AUTHOR]

Background: Fritillaria ussuriensis is an endangered medicinal plant known for its notable therapeutic properties. Unfortunately, its population has drastically declined due to the destruction of forest habitats. Thus, effectively protecting F. ussuriensis from extinction poses a significant challenge. A profound understanding of its genetic foundation is crucial. To date, research on the complete mitochondrial genome of F. ussuriensis has not yet been reported. Results: The complete mitochondrial genome of F. ussuriensis was sequenced and assembled by integrating PacBio and Illumina sequencing technologies, revealing 13 circular chromosomes totaling 737,569 bp with an average GC content of 45.41%. A total of 55 genes were annotated in this mitogenome, including 2 rRNA genes, 12 tRNA genes, and 41 PCGs. The mitochondrial genome of F. ussuriensis contained 192 SSRs and 4,027 dispersed repeats. In the PCGs of F. ussuriensis mitogenome, 90.00% of the RSCU values exceeding 1 exhibited a preference for A-ended or U-ended codons. In addition, 505 RNA editing sites were predicted across these PCGs. Selective pressure analysis suggested negative selection on most PCGs to preserve mitochondrial functionality, as the notable exception of the gene nad3 showed positive selection. Comparison between the mitochondrial and chloroplast genomes of F. ussuriensis revealed 20 homologous fragments totaling 8,954 bp. Nucleotide diversity analysis revealed the variation among genes, and gene atp9 was the most notable. Despite the conservation of GC content, mitogenome sizes varied significantly among six closely related species, and colinear analysis confirmed the lack of conservation in their genomic structures. Phylogenetic analysis indicated a close relationship between F. ussuriensis and Lilium tsingtauense. Conclusions: In this study, we sequenced and annotated the mitogenome of F. ussuriensis and compared it with the mitogenomes of other closely related species. In addition to genomic features and evolutionary position, this study also provides valuable genomic resources to further understand and utilize this medicinal plant. [ABSTRACT FROM AUTHOR]

Fulgoraria rupestris is a predatory marine gastropod belonging to Neogastropoda and possessing considerable taxonomic significance. However, research on this species remains limited. We acquired the complete mitochondrial genome of F. rupestris through second-generation sequencing and conducted an analysis of its genome structural features. The mitochondrial genome of F. rupestris spans a total length of 16,223 bp and encompasses 37 genes (13 protein-coding genes (PCGs), 22 transfer RNAs, and 2 ribosomal RNAs). Notably, most tRNAs exhibit the typical cloverleaf structure, but there is an absence of the Dihydrouridine (DHU) arm in the trnS1 and trnS2 genes. The A + T content is 68.67%, indicating a pronounced AT bias. Additionally, we conducted a selection pressure analysis on the mitochondrial genomes of four species within Volutidae, revealing that all PCGs are subjected to purifying selection. In comparison to other species within Neogastropoda, F. rupestris shares an identical gene arrangement. Additionally, based on mitochondrial genome sequences of the 13 PCGs from 50 species within Neogastropoda, we constructed a phylogenetic tree. The phylogenetic tree indicates F. rupestris forms a clade with species within the family Volutidae (Cymbium olla, Neptuneopsis gilchristi, and Melo melo). This study serves as a valuable reference for future research on F. rupestris, offering insights for the upcoming phylogenetic and taxonomic classification within Neogastropoda. Furthermore, the findings provide valuable information for the development of genetic resources in this context. [ABSTRACT FROM AUTHOR]

Macrocystis pyrifera (Linnaeus) C. Agardh 1820 is a type of algae widely located along the Chilean coastline with extensive biological value. Mitochondrial genome is 37 289 bp in length and consists of a circular DNA molecule. The circular genome is composed of 66 genes, including 38 protein coding genes, 25 tRNA genes, and 3 rRNA genes. The total content of G+C is 31.80%, lower than that of A+T. M. pyrifera formed a monophyletic clade together with Macrocystis integrifolia, which offer valuable insights into the phylogeny and gene functions within the family Laminariaceae andpromote novel references for the genetic and phylogenetic research of M. pyrifera through the provision of these data. [ABSTRACT FROM AUTHOR]

The complete mitochondrial DNA sequence of a deep-sea eel Congriscus megastoma (Anguilliformes: Congridae) was determined by high throughput sequencing technology. As the first mitogenome of the genus Congriscus up to now, its entire mtDNA sequence was 17,616 bp in length, including 37 mitochondrial genes (13 protein-coding genes, 2 rRNA genes, 22 tRNA genes) and 2 control regions, which was inconsistent with that of the typical vertebrate mitogenomes. In addition, the genes of C. megastoma exhibited an obvious rearrangement. ND6 and tRNA-Glu were transferred between tRNA-Thr and tRNA-Pro, as well as a doubled control region appeared. The tandem duplication-random loss (TDRL) model was an ideal explanation for this irregular gene reorganization phenomenon. The Bayesian phylogenetic tree showed that Congridae species were divided into four clades, suggesting their non-monophyletic origin. Congriscus had the closest relationships with Thalassenchelys and Coloconger. Species with gene rearrangement separately clustered as one clade. The results provided a basis for future studies of mitochondrial DNA structure and phylogeny of Anguilliformes. [ABSTRACT FROM AUTHOR]

Boulenophrys sangzhiensis and Boulenophrys tuberogranulata, two narrow‐distributed toad species within the Megophryidae family in southern China, are experiencing population declines due to habitat loss and degradation. Despite their critical conservation status, the two species remain largely overlooked in public and scientific spheres. This study presented the first sequencing, assembly, and annotation of the complete mitogenomes of both species using next‐generation sequencing. The mitogenome of B. sangzhiensis was 16,950 bp, while that of B. tuberogranulata was 16,841 bp, each comprising 13 protein‐coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and a noncoding control region (D‐loop). The gene content, nucleotide composition, and evolutionary rates of each mitogenome were analyzed. Both mitogenomes exhibited negative AT skew and GC skew with high A + T content. ATP8 exhibited the highest evolutionary rate, while COI had the lowest. A phylogenetic analysis based on 28 mitogenomes revealed two major clades of Megophryidae, supporting the classification of two subfamilies, Megophryinae and Leptobrachiinae. Within the subfamily Megophryinae, the genus Boulenophrys was divided into two species groups. Intriguingly, despite coexisting in Zhangjiajie City, B. sangzhiensis and B. tuberogranulata exhibited distinct origins from the two different species groups, underscoring the unique role of the coexisting area Zhangjiajie in driving their speciation and preserving their current populations. A parallel pattern was also identified in the Leptobrachiinae genus Leptobrachium within the same region. This study provided valuable data references and enhanced our understanding of the molecular characteristics of these threatened amphibian species. [ABSTRACT FROM AUTHOR]

Simple Summary: Aradidae is a large family in Hemiptera, which feeds on mycelium, and its phylogenetic status is not fully understood. Mitochondrial genome sequences can be used to study species identification and phylogeny, and provide valuable molecular markers for further genetic research. In this paper, we sequenced three species of the genus Yangiella for the first time, assembled three mitochondrial genomes, and compared the general characteristics of the mitochondrial genomes of the three species. It was found that the base composition and mitochondrial genome structure of the three species were highly similar. The phylogeny of Yangiella was also discussed. Based on the phylogenetic analyses results of two data matrices, the status of Yangiella was discussed and the monophyly of this genus was verified. In addition, we infer that the genus Yangiella diverged about 57 million years ago. The mitochondrial genomes of three species of Yangiella were sequenced, annotated, and analyzed. The genome length of the three species of the genus is 15,070–15,202 bp, with a typical gene number, including a control region, 2 ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and 13 protein-coding genes (PCGs). It was found that the mitochondrial genome of Yangiella had AT bias. Except for the lack of a DHU arm of the trnS1 gene, the other tRNAs had a typical cloverleaf structure, and the codon usage preferences of the three species exhibited high similarity. In addition, tRNA gene rearrangements were observed among the three subfamilies of Aradidae (Mezirinae, Calisiinae, Aradinae), and it was found that codon usage preferences appeared to be less affected by base mutation and more by natural selection. The Pi and Ka/Ks values indicated that cox1 was the most conserved gene in the mitochondrial genome of Aradidae, while atp8 and nad6 were rapidly evolved genes. Substitution saturation level analysis showed that the nucleic acid sequence of mitochondrial protein-coding genes in Aradidae did not reach saturation, suggesting the rationality of the phylogenetic analysis data. Bayesian and maximum likelihood methods were used to analyze the phylogeny of 16 species of Hemiptera insects, which supported the monophyly of Aneurinae, Carventinae, and Mezirinae, as well as the monophyly of Yangiella. Based on fossils and previous studies, the differentiation time was inferred, indicating that Yangiella diverged about 57 million years ago. [ABSTRACT FROM AUTHOR]

Simple Summary: The mitochondrial genome (mitogenome) has been used extensively to investigate phylogenetic relationships at various taxonomic levels. Insect mitochondrial genomes are important for understanding insect evolution and relationships. We performed complete mitogenome sequencing and annotation for nine Meconematinae species and combined the data with data from previously assembled mitochondrial genomes in the family Tettigoniidae to conduct a phylogenetic analysis. The monophyly of Xizicus, Xiphidiopsis, and Phlugiolopsis was not well supported in our findings. Currently, the subfamily Meconematinae encompasses 1029 species, but whole-mitochondrial-genome assemblies have only been made available for 13. In this study, the whole mitochondrial genomes (mitogenomes) of nine additional species in the subfamily Meconematinae were sequenced. The size ranged from 15,627 bp to 17,461 bp, indicating double-stranded circular structures. The length of the control region was the main cause of the difference in mitochondrial genome length among the nine species. All the mitogenomes including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs) and a control region (CR). The majority strand encoded 23 genes, and the minority strand encoded 14 genes. A phylogenetic analysis reaffirmed the monophyletic status of each subfamily, but the monophysitism of Xizicus, Xiphidiopsis and Phlugiolopsis was not supported. [ABSTRACT FROM AUTHOR]

The mitogenome is an important tool for taxonomic and evolutionary investigation. Here, a few complete mitogenomes of red algae have been reported. We have reported the complete mitogenome sequences of Grateloupia cornea Okamura, 1913 (Rhodophyta, Halymeniales). The genome is 30,595 bp in circumference, and has a strongly biased [AT] = 66.9%. Like most other Grateloupia species, it has a group II intron in the cox1 gene. Maximum likelihood and maximum parsimony analyses showed that G. cornea is more closely related to G. asiatica. This shows that the group II intron in the cox1 ORF present in most species of Grateloupia was present in their common ancestor, and uniquely lost in G. asiatica. The seven Grateloupia species with known mitogenome sequences remain monophyletic, with the genus Polyopes as sister taxon. The complete mitochondrial genome data will be valuable for future research on comparative mitochondrial genome analysis, an extensive understanding of gene content and organization, evolution of the cox1 intron in Rhodophyta as well as phylogenetic analysis. [ABSTRACT FROM AUTHOR]

Diplopoda is one of the most diverse and important groups of soil arthropods, but little research has been done on their phylogenetic relationship and evolution. Here, we sequenced and annotated the complete mitochondrial genomes of Spirobolus grahami. The total mitogenome of S. grahami was typical circular, double-stranded molecules, with 14,875 bp in length, including 13 protein-coding genes, 22 tRNAs, two rRNAs, and one control region. Base composition analysis suggested that the mitochondrial sequences were biased toward A and T, with A + T content of 58.68%. The mitogenomes of S. grahami exhibited negative AT and positive GC skews. Most of the 13 PCGs had ATN as the start codon, except COX1 start with CGA, and most PCGs ended with the T stop codon. The dN/dS values for most PCGs were lower than 1, suggesting that purifying selection was likely the main driver of mitochondrial PCG evolution. Phylogenetic analyses based on 13 PCGs using BI and ML methods support the classification of genus Spirobolus and Tropostreptus. Glomeridesmus spelaeus is distantly related to the other Diplopoda species. [ABSTRACT FROM AUTHOR]

The systematic revision of the family Peristediidae remains an unresolved issue due to their diverse and unique morphology. Despite the popularity of using mitochondrial genome research to comprehensively understand phylogenetic relationships in fish, genetic data for peristediid fish need to be included. Therefore, this study aims to investigate the mitochondrial genomic characteristics and intra-family phylogenetic relationships of Peristediidae by utilizing mitochondrial genome analysis. Therefore, this study aims to investigate the phylogenetic relationship of Peristediidae by utilizing mitochondrial genome analysis. The mitochondrial genome of four species of Peristediidae (Peristedion liorhynchus, Satyrichthys welchi, Satyrichthys rieffeli, and Scalicus amiscus) collected in the East China Sea was studied. The mitochondrial gene sequence lengths of four fish species were 16,533 bp, 16,526 bp, 16,527 bp, and 16,526 bp, respectively. They had the same mitochondrial structure and were all composed of 37 genes and one control region. Most PCGs used ATG as the start codon, and a few used GTG as the start codon. An incomplete stop codon (TA/T) occurred. The AT-skew and GC-skew values of 13 PCGs from four species were negative, and the GC-skew amplitude was greater than that of AT-skew. All cases of D-arm were found in tRNA-Ser (GCT). The Ka/Ks ratio analysis indicated that 13 PCGs were suffering purifying selection. Based on 12 PCGs (excluding ND6) sequences, a phylogenetic tree was constructed using Bayesian inference (BI) and maximum likelihood (ML) methods, providing a further supplement to the scientific classification of Peristediidae fish. According to the results of divergence time, the four species of fish had apparent divergence in the Early Cenozoic, which indicates that the geological events at that time caused the climax of species divergence and evolution. [ABSTRACT FROM AUTHOR]

Tylopilus brunneirubens is a common species in southern China. It is known for brown to dark brown pileus, white context turning reddish brown or rust brown when touched and distinct reticulation on the upper stem. However, little is known about its mitochondrial genome and its relationship with other boletes. Our analysis revealed that the mitochondrial genome of this species is a circular DNA molecule that spans 32,389 bp. It contains 15 core protein-coding genes, 24 transfer RNA genes, and two ribosomal RNA genes. The base composition of the mitochondrial genome is as follows: A (37.20%), C (11.32%), G (12.48%), and T (39.00%), with a GC content of 23.80%. Furthermore, a phylogenetic tree based on 24 mitochondrial genomes provided valuable insights into the phylogenetic relationships of Tylopilus brunneirubens with other boletes for the first time. [ABSTRACT FROM AUTHOR]

Background: Primulina hunanensis, a troglobitic plant within the Primulina genus of Gesneriaceae family, exhibits robust resilience to arid conditions and holds great horticultural potential as an ornamental plant. The work of chloroplast genome (cpDNA) has been recently accomplished, however, the mitochondrial genome (mtDNA) that is crucial for plant evolution has not been reported. Results: In this study, we sequenced and assembled the P. hunanensis complete mtDNA, and elucidated its evolutionary and phylogenetic relationships. The assembled mtDNA spans 575,242 bp with 43.54% GC content, encompassing 60 genes, including 37 protein-coding genes (PCGs), 20 tRNA genes, and 3 rRNA genes. Notably, high number of repetitive sequences in the mtDNA and substantial sequence translocation from chloroplasts to mitochondria were observed. To determine the evolutionary and taxonomic positioning of P. hunanensis, a phylogenetic tree was constructed using mitochondrial PCGs from P. hunanensis and 32 other taxa. Furthermore, an exploration of PCGs relative synonymous codon usage, identification of RNA editing events, and an investigation of collinearity with closely related species were conducted. Conclusions: This study reports the initial assembly and annotation of P. hunanensis mtDNA, contributing to the limited mtDNA repository for Gesneriaceae plants and advancing our understanding of their evolution for improved utilization and conservation. [ABSTRACT FROM AUTHOR]

Libelloides sibiricus (Eversmann, 1850) is widely distributed in China, Korea and eastern Russia. To date, few studies have been conducted on this species, with the exception of morphological taxonomy studies. In this study, we sequenced the complete mitochondrial genome (mitogenome) of Libelloides sibiricus, which is 15,811 bp in length, with an overall A + T content of 74.8%, encoding 2 ribosomal RNA genes, 22 transfer RNA genes, 13 protein-coding genes, and a control region. The gene arrangement and components of L. sibiricus are identical to those of most other Neuropteran species. TAA is utilized as the termination codon for most PCGs and TAG for nd1, however, nd6 and atp6 used the incomplete termination codon TA- and cox1, cox2, nd5, cytb had termination codons consisting of only T–. In addition, we selected all known 59 species of Neuroptera from NCBI, and used Sialis hamata, Sialis melania, Sialis longidens and Sialis jiyuni (Megaloptera: Sialidae) as the outgroup. Phylogenetic analysis suggested that the mitogenome of L. sibiricus was the most closely related to L. macaronius and all the owlflies formed the monophyletic group within the superfamily Myrmeleontoidea. [ABSTRACT FROM AUTHOR]

The saddleback silver-biddy Gerres limbatus (Cuvier 1830) is distributed in Indo-West Pacific Oceans and associated with shallow coastal marine waters and estuaries. In this study, the complete mitochondrial genome of G. limbatus was firstly documented, which is 16,730 bp in length, including 13 protein-coding genes, 22 transfer RNA genes and 2 ribosomal RNA genes. The overall base composition of the mitochondrial genome is 26.42% A, 28.68% C, 27.32% T, and 17.58% G. The Maximum Likelihood phylogenetic tree was constructed based on COI gene of the 31 species from the family Gerreidae, with Heteroclinus puellarum and Hypopterus macropterus as outgroups. It revealed that G. erythrourus was placed as the sister group to G. limbatus. [ABSTRACT FROM AUTHOR]

Pseudanthias pascalus (Jordan & Tanaka, 1927) (Perciformes: Serranidae) is a species of brightly colored saltwater fish found in tropical coastal reef communities. In this study, we reported the sequence of mitochondrial DNA from P. pascalus. The accession number is OP611422. The complete mitochondrial genome of P. pascalus was 16,863 bp in length, including 13 protein-coding genes (PCGs), 12S and 16S rRNAs, 22 tRNA genes, and one displacement loop (D-loop). Most PCGs had ATG-start codons and TAA-end codons. The A + T contents were 54.61%. Phylogenetic analysis showed that P. pascalus is most closely related to Pseudanthias huchtii. We sequenced the entire mitochondrial genome of P. pascalus, providing improved marker identification information for the classification of the family and species conservation. These data will be useful for relative ecological and phylogenetic studies. [ABSTRACT FROM AUTHOR]

Chickens in free-range environments are at risk of exposure to various pathogens, such as filarioids transmitted via hematophagous vectors. However, the study of filarioids in poultry has been largely neglected compared to the extensive studies focused on viruses, bacteria, and protozoa. Here, we performed histological and molecular investigations of the filarioids detected in domestic chickens from two different flocks in Hiroshima Prefecture, Japan. In the first case, adult worms were present in the pulmonary artery and right ventricle, and microfilariae were present in multiple organs of deceased chickens. In the second case, similar filarioids were detected in the organs and blood of one necropsied layer. Phylogenetic analysis using 18S rRNA gene fragments positioned the filarioid in the same clade as that of Onchocercidae sp., previously identified in a deceased chicken from Chiba Prefecture, Japan, that is located 500 km away from Hiroshima Prefecture. Based on 28S rRNA and mitochondrial COI gene fragments, the filarioid was positioned distinctly from previously reported genera of avian filarioids. These results suggest that the filarioids are potentially associated with the health burden on domestic chickens and belong to the genus Paronchocerca. Furthermore, we developed a nested PCR assay targeting mitochondrial COI and detected the parasite DNA from the biting midge Culicoides arakawae captured near the flock, suggesting that it serves as a vector. Our findings fill the knowledge gap regarding avian filarioids, laying the groundwork for future studies examining the epidemiology, life cycle, and species diversity of this neglected parasite group. [ABSTRACT FROM AUTHOR]

In this study, we conducted an assembly and analysis of the organelle genomes of Aconitum carmichaelii. Our investigation encompassed the examination of organelle genome structures, gene transfer events, and the environmental selection pressures afecting A. carmichaelii. The results revealed distinct evolutionary patterns in the organelle genomes of A. carmichaelii. Especially, the plastome exhibited a more conserved structure but a higher nucleotide substitution rate (NSR), while the mitogenome displayed a more complex structure with a slower NSR. Through homology analysis, we identified several instances of unidirectional protein-coding genes (PCGs) transferring from the plastome to the mitogenome. However, we did not observe any events which genes moved from the mitogenome to the plastome. Additionally, we observed multiple transposable element (TE) fragments in the organelle genomes, with both organelles showing different preferences for the type of nuclear TE insertion. Divergence time estimation suggested that rapid differentiation occurred in Aconitum species approximately 7.96 million years ago (Mya). This divergence might be associated with the reduction in CO2 levels and the significant uplift of the Qinghai-Tibet Plateau (QTP) during the late Miocene. Selection pressure analysis indicated that the dN/dS values of both organelles were less than 1, suggested that organelle PCGs were subject to purification selection. However, we did not detect any positively selected genes (PSGs) in Subg. Aconitum and Subg. Lycoctonum. This observation further supports the idea that stronger negative selection pressure on organelle genes in Aconitum results in a more conserved amino acid sequence. In conclusion, this study contributes to a deeper understanding of organelle evolution in Aconitum species and provides a foundation for future research on the genetic mechanisms underlying the structure and function of the Aconitum plastome and mitogenome. [ABSTRACT FROM AUTHOR]

Simple Summary: As an endemic and vulnerable fish from the upper Yangtze River in China, Schizothorax kozlovi holds significant scientific and ecological importance, yet it has received little attention so far. In this paper, we reported the characterization of the mitochondrial genome of S. kozlovi, and further investigated the phylogenetic relationships of Schizothorax. The results showed that the mitochondrial genome of S. kozlovi had a total size of 16,585 bp, a circular arrangement, and contained 13 PCGs, 22 tRNAs, two rRNAs, and two non-coding regions. Moreover, the phylogenetic analyses demonstrated that Schizothorax could be classified into four clades, and S. kozlovi was closely related to Schizothorax chongi. The present study enriched the basic biological data for S. kozlovi and provided fundamental references for the conservation of S. kozlovi and Schizothorax. Schizothorax kozlovi is an endemic and vulnerable fish species found in the upper Yangtze River in China. Over the past few years, the population resources of S. kozlovi have been nearly completely depleted owing to multiple contributing threats. While the complete mitochondrial genomes serve as important molecular markers for phylogenetic and genetic studies, the mitochondrial genome of S. kozlovi has still received little attention. In this study, we analyzed the characterization of the mitochondrial genome of S. kozlovi and investigated the phylogenetic relationships of Schizothorax. The complete mitochondrial genome of S. kozlovi was 16,585 bp in length, which contained thirty-seven genes (thirteen protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs), twenty-two transfer RNA genes (tRNAs)) and two non-coding regions for the origin of light strand (OL) and the control region (CR). There were nine overlapping regions and seventeen intergenic spacers regions in the mitochondrial genome. The genome also showed a bias towards A + T content (55.01%) and had a positive AT-skew (0.08) and a negative GC-skew (−0.20). All the PCGs employed the ATG or GTG as the start codon and TAA, TAG, or single T as the stop codon. Additionally, all of the tRNAs displayed a typical cloverleaf secondary structure, except trnS1 which lacked the D arm. The phylogenetic analysis, based on the maximum likelihood (ML) and Bayesian inference (BI) methods, revealed that the topologies of the phylogenetic tree divided the Schizothorax into four clades and did not support the classification of Schizothorax based on morphology. The phylogenetic status of S. kozlovi was closely related to that of S. chongi. The present study provides valuable genomic information for S. kozlovi and new insights in phylogenetic relationships of Schizothorax. These data could also offer fundamental references and guidelines for the management and conservation of S. kozlovi and other species of Schizothorax. [ABSTRACT FROM AUTHOR]

German chamomile (Matricaria chamomilla L.) and Roman chamomile (Chamaemelum nobile) are the two well-known chamomile species from the Asteraceae family. Owing to their essential oils and higher medicinal value, these have been cultivated widely across Europe, Northwest Asia, North America, and Africa. Regarding medicinal applications, German chamomile is the most commonly utilized variety and is frequently recognized as the "star among medicinal species". The insufficient availability of genomic resources may negatively impact the progression of chamomile industrialization. Chamomile's mitochondrial genome is lacking in extensive empirical research. In this study, we achieved the successful sequencing and assembly of the complete mitochondrial genome of M. chamomilla and C. nobile for the first time. An analysis was conducted on codon usage, sequence repeats within the mitochondrial genome of M. chamomilla and C. nobile. The phylogenetic analysis revealed a consistent positioning of M. chamomilla and C. nobile branches within both mitochondrial and plastid-sequence-based phylogenetic trees. Furthermore, the phylogenetic analysis also showed a close relationship between M. chamomilla and C. nobile within the clade comprising species from the Asteraceae family. The results of our analyses provide valuable resources for evolutionary research and molecular barcoding in chamomile. [ABSTRACT FROM AUTHOR]

Hericium erinaceus (Bull.:Fr.) Pers., 1797, is an edible and medicinal fungus found in China. In this study, specimens of H. erinaceus HE0021 were collected from southeastern China (Yunhe County, Lishui City, Zhejiang Province, 28°7′12″N, 119°34′12″E). The whole mitochondrial genome of H. erinaceus HE0021 was sequenced using next-generation sequencing (NGS) technology, which comprised 15 protein-coding genes (PCGs), 27 transfer RNAs (tRNAs), two ribosomal RNAs, with a total length of 83,518 base pairs (bp). The results of the phylogenetic analysis show that H. erinaceus and H. coralloides were clustered in the same clade. The complete mitogenome sequence provides essential data for the subsequent investigation of Hericium and Russulales. [ABSTRACT FROM AUTHOR]

Background: Aquilegia is a model system for studying the evolution of adaptive radiation. However, very few studies have been conducted on the Aquilegia mitochondrial genome. Since mitochondria play a key role in plant adaptation to abiotic stress, analyzing the mitochondrial genome may provide a new perspective for understanding adaptive evolution. Results: The Aquilegia amurensis mitochondrial genome was characterized by a circular chromosome and two linear chromosomes, with a total length of 538,736 bp; the genes included 33 protein-coding genes, 24 transfer RNA (tRNA) genes and 3 ribosomal RNA (rRNA) genes. We subsequently conducted a phylogenetic analysis based on single nucleotide polymorphisms (SNPs) in the mitochondrial genomes of 18 Aquilegia species, which were roughly divided into two clades: the European-Asian clade and the North American clade. Moreover, the genes mttB and rpl5 were shown to be positively selected in European-Asian species, and they may help European and Asian species adapt to environmental changes. Conclusions: In this study, we assembled and annotated the first mitochondrial genome of the adaptive evolution model plant Aquilegia. The subsequent analysis provided us with a basis for further molecular studies on Aquilegia mitochondrial genomes and valuable information on adaptive evolution in Aquilegia. [ABSTRACT FROM AUTHOR]

This study presents the complete mitochondrial genome (mitogenome) of Litostrophus scaber, which is the first mitogenome of the genus Litostrophus. The mitogenome is a circular molecule with a length of 15,081 bp. The proportion of adenine and thymine (A + T) was 69.25%. The gene ND4L used TGA as the initiation codon, while the other PCGs utilized ATN (A, T, G, C) as the initiation codons. More than half of the PCGs used T as an incomplete termination codon. The transcription direction of the L. scaber mitogenome matched Spirobolus bungii, in contrast to most millipedes. Novel rearrangements were found in the L. scaber mitogenome: trnQ -trnC and trnL1- trnP underwent short-distance translocations and the gene block rrnS-rrnL-ND1 moved to a position between ND4 and ND5, resulting in the formation of a novel gene order. The phylogenetic analysis showed that L. scaber is most closely related to S. bungii, followed by Narceus magnum. These findings enhance our understanding of the rearrangement and evolution of Diplopoda mitogenomes. [ABSTRACT FROM AUTHOR]

Pinellia ternata is an important natural medicinal herb in China. However, it is susceptible to withering when exposed to high temperatures during growth, which limits its tuber production. Mitochondria usually function in stress response. The P. ternata mitochondrial (mt) genome has yet to be explored. Therefore, we integrated PacBio and Illumina sequencing reads to assemble and annotate the mt genome of P. ternata. The circular mt genome of P. ternata is 876 608 bp in length and contains 38 protein-coding genes (PCGs), 20 tRNA genes and three rRNA genes. Codon usage, sequence repeats, RNA editing and gene migration from chloroplast (cp) to mt were also examined. Phylogenetic analysis based on the mt genomes of P. ternata and 36 other taxa revealed the taxonomic and evolutionary status of P. ternata. Furthermore, we investigated the mt genome size and GC content by comparing P. ternata with the other 35 species. An evaluation of non-synonymous substitutions and synonymous substitutions indicated that most PCGs in the mt genome underwent negative selection. Our results provide comprehensive information on the P. ternata mt genome, which may facilitate future research on the high-temperature response of P. ternata and provide new molecular insights on the Araceae family. [ABSTRACT FROM AUTHOR]

Caenogastropoda is a highly diverse group, containing ∼60% of all existing gastropods. Species in this subclass predominantly inhabit marine environments and have a high ecological and economic value. Owing to the increase in relevant phylogenetic studies, our understanding of between species relatedness in Caenogastropoda has improved. However, the biodiversity, taxonomic status, and phylogenetic relationships of this group remain unclear. In the present study, we performed next-generation sequencing of four complete mitochondrial genomes from three families (Buccinidae, Columbellidae, and Cypraeidae) and the four mitogenomes were classical circular structures, with a length of 16 177 bp in Volutharpa ampullacea, 16 244 bp in Mitrella albuginosa, 16 926 bp in Mauritia arabica asiatica and 15 422 bp in Erronea errones. Base composition analysis indicated that whole sequences were biased toward A and T. Then compared them with 171 complete mitochondrial genomes of Caenogastropoda. The phylogenetic relationship of Caenogastropoda derived from Maximum Likelihood (ML) and Bayesian Inference (BI) trees constructed based on CDS sequences was consistent with the results of traditional morphological analysis, with all three families showing close relationships. This study supported Caenogastropoda at the molecular level as a separate clade of Mollusca. According to our divergence time estimations, Caenogastropoda was formed during the middle Triassic period (∼247.2–237 Ma). Our novel mitochondrial genomes provide evidence for the speciation of Caenogastropoda in addition to elucidating the mitochondrial genomic evolution of this subclass. [ABSTRACT FROM AUTHOR]

Simple Summary: When we refer to aquatic fireflies, we are actually referring to their larvae, as the adults are free-flying. Many species of fireflies have been collected from terrestrial specimens only and may not have any information to indicate the larval habitat. The ideal situation is to rear specimens from eggs laid, but this is a difficult venture and is not always successful. More recently, the use of molecular genetics, especially the genome of the mitochondrion, has enabled us to match larvae with adults with great confidence. Here, we address two new species of aquatic fireflies from China where the aquatic association is confirmed, and the relationships of these species with other aquatic fireflies are established. There are now seven species in the genus Aquatica Fu & Ballantyne, with all but one known from the characteristics of males, females, and larvae. Molecular information is combined with morphological taxonomy for the delimitation of both genus and species. The monophyly of the genus Aquatica is strongly supported in six trees, and its position as sister to the genus Nipponoluciola Ballantyne Kawashima Jusoh et Suzuki is stable across maximum likelihood and Bayesian inference results. Two new species of Aquatica Fu & Ballantyne, A. qingshen sp. nov. and A. xianning sp. nov., described from the features of males, females, and larvae, are closely related within a single clade within the genus Aquatica. Females have distinctively shaped median oviduct plates. A Chinese population identified as A. lateralis was found to be morphologically similar to the Japanese population, but genetic distances suggest that it is a distinctive species. No larvae are associated with this species. Definitions of the aquatic status of Luciolinae fireflies are expanded. [ABSTRACT FROM AUTHOR]

Notonecta triguttata Motschulsky, 1861 (Hemiptera, Notonectidae) is distributed in China, Japan, and South Korea. It is the dominant hexapod predator in aquatic ecosystems and can control harmful insects, such as mosquitoes and parasites. This study presents the first determination of the complete mitochondrial genome of N. triguttata. The mitogenome was 15,156 base pairs in length and was made up of 13 protein-coding genes (PCGs), 2 ribosomal RNAs, 22 transfer RNAs, and one non-coding control region. All genes were arranged in the same order as most other known heteropteran mitogenomes. All PCGs started with the ATN codon except COX1 (TTG) and NAD2 (GTG) and ended with TAA, TAG, or the partial stop codon T. The tRNAs had a typical cloverleaf secondary structure, except tRNA-Ser (GCT). The A + T content (75.96%) was relatively high across the entire mitogenome. The optimal phylogenetic trees were inferred through the Bayesian inference and maximum likelihood methods. The trees suggested a topology of (Corixoidea + ((Nepoidea + Ochteroidea) + (Naucoroidea + (Pleoidea + Notonectoidea)))) and identified that N. triguttata belongs to Notonectoidea. The complete mitogenome of N. triguttata provides a potentially useful resource for further exploration of the taxonomic status and phylogenetic history of the Notonecta species. [ABSTRACT FROM AUTHOR]

Phyllosticta yuccae is an important plant pathogen causing leaf spot disease in Yucca gigantea Lem. It is imperative to note that the amount of information available about the mitogenome of this subject is severely limited. This must be addressed immediately, as it is crucial to our understanding and progress in this field. To better understand the mitogenomic characteristics of P. yuccae, we conducted its sequencing by MGISEQ. Afterwards, the mitogenome was assembled and annotated. The mitogenomic characteristics and phylogenetic placement of the P. yuccae strain KUMCC 6213 were analyzed. The study revealed that the mitogenome of P. yuccae is a circular DNA molecule, consisting of 178,540 base pairs. It contains a total of 64 genes, including 14 protein-coding genes (PCGs), 26 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and 22 open reading frame genes (ORF), accounting for 80.98% of the total size. Repetitive sequences accounted for 15.42% of the mitogenome. The analysis of codon usage indicated that the codon UUA was the most commonly utilized, whereas the amino acid Leu was the most frequently employed. A comparative analysis of mitogenomes between P. yuccae and Macrophomina phaseolina (Tassi) Goid. showed notable variations in the position and size of gene clusters, with cox1, nad4, and nad4L genes exhibiting relatively low conservation. Phylogenetic analysis based on the 14 PCGs revealed that P. yuccae has the closest genetic relationship with M. phaseolina (Botryosphaeriaceae, Botryosphaeriales). This study first reports the mitogenome of P. yuccae and validates its phylogenetic placement. The findings enhance the knowledge of mitogenomes in Botryosphaeriales, offering novel perspectives on the genetics and evolution of the plant pathogen P. yuccae. This is crucial for the accurate prevention and management of leaf spot disease in Y. gigantea. [ABSTRACT FROM AUTHOR]

The genus Littoraria plays a significant role in the ecology of intertidal communities and is one of the very few molluscan groups that are closely associated with mangroves. To provide genomic resources for these species, we sequenced the complete mitochondrial genome of Littoraria ardouiniana (Heude, 1885) in this study. The results show that the complete mitogenome sequence of L. ardouiniana was circular and 16,261 bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 non-coding control region. The overall base composition of the mitogenome was 28.95% A, 34.32% T, 15.31% G, and 21.42% C, exhibiting negative AT-skew (–0.109) and GC-skew (–0.196). All PCGs are located on the heavy (H) strand and had a typical initiation codon ATG, and ended with TAA, except for nad2, which ended with T–. Phylogenetic analysis indicated that L. ardouiniana was closely related to Littoraria melanostoma, Littoraria intermedia, and Littoraria sinensis. This study first reported the complete mitochondrial genome of L. ardouiniana and provides valuable data for future molecular evolutionary and conservation studies of the genus Littoraria. [ABSTRACT FROM AUTHOR]

The mitogenome of Bauhinia variegate was assembled and characterized in this study. The mitogenome size was 437,271 bp, and its GC content was 45.5%. 36 protein-coding genes, 17 tRNAs and 3 rRNAs were annotated in the mitogenome. A total of 12 MTPTs, ranging from 71 bp to 3562 bp, were identified in the mitogenome and covered 1.46% (6373 bp) of the mitogenome. Phylogenetic analysis of 15 species of Leguminosae based on 23 core protein-coding genes showed that B. variegata was sister to Tylosema esculentum, another member from the subfamily Cercidoideae. The mitogenome of B. variegata provides a valuable genetic resource for further phylogenetic studies of this family. [ABSTRACT FROM AUTHOR]

Vischeria punctata, as first described by Vischer in 1945, is a member of the family Chlorobotryaceae, within the order Eustigmatales. This species is recognized for its potential as a source of biofuels and other high-value products. In the present investigation, the whole genome of V. punctata was sequenced utilizing the Illumina HiSeq 4000 platform, enabling the assembly and annotation of its complete mitochondrial genome. The resulting circular genome spans 41,528 base pairs (bp) with a guanine-cytosine (GC) content of 27.3%. This genome encompasses 36 protein-coding genes, alongside 28 transfer RNA (tRNA), and three ribosomal RNA (rRNA) genes. The evolutionary trajectory of V. punctata was further explored by constructing a phylogenetic tree derived from the mitochondrial 33 gene dataset of 16 Ochrophyta species. Comparative analysis reveals that V. punctata bears closer ties to Vischeria sp. CAUP Q202 than to Vischeria stellata strain SAG 33.83, suggesting shared evolutionary pathways and phenotypic traits. This investigation constitutes the inaugural study into the mitochondrial evolution and phylogenetic patterning of the mitogenome in V. punctata. The outcomes from this research bolster our understanding of the genetic diversity and evolutionary processes within the class Eustigmatophyceae. In particular, the mitochondrial genome of V. punctata serves as a valuable resource in elucidating these aspects. [ABSTRACT FROM AUTHOR]

Butyriboletus hainanensis, a macrofungus belonging to the Boletaceae family, is named after its collection location on Hainan Island, China. However, little is known about its mitochondrial genome and its phylogenetic relationship with other boletes. In this study, we utilized next-generation sequencing technology to sequence the mitochondrial genome of Bu. hainanensis. Our findings revealed that the mitochondrial genome of this species is presumably a circular DNA molecule spanning 36,592 bp. It consists of 15 protein-coding genes, 27 transfer RNA genes, and two ribosomal RNA genes. The base composition of the mitochondrial genome is as follows: A (36.64%), C (12.22%), G (11.73%), and T (39.41%), with a GC content of 23.95%. Additionally, a phylogenetic tree was constructed based on 22 mitochondrial genomes, which provided valuable insights into the phylogenetic relationships of Bu. hainanensis with other boletes for the first time. [ABSTRACT FROM AUTHOR]

Micromelalopha sieversi (Staudinger, 1892) is a significant pest of Poplar trees in China. In this study, we used high-throughput sequencing to sequence the whole mitochondrial genome of M. sieversi. The length of the genome was 15,373 base pairs. The nucleotide composition was 39.8%, 11.5%, 8.0%, and 40.7% for A, C, G, and T, respectively. We used the maximum-likelihood method to construct a molecular phylogenetic tree based on complete mitogenome sequences of 19 Noctuoidea species as ingroups and five Geometroidea species as outgroups. The results indicate that the genus Micromelalopha is closely related to the genus Clostera in family Notodontidae. [ABSTRACT FROM AUTHOR]

Aureoboletus raphanaceus is a member of boletoid mushroom, which is named after its distinctive radish smell. The mitochondrial genome and phylogenetic relationships with other boletes need to be investigated to gain a comprehensive understanding of it. In this study, we sequenced the mitochondrial genome of A. raphanaceus using next-generation sequencing technology and found that its mitochondrial genome is a circular DNA molecule measuring 42,157 bp. It consists of 15 core protein-coding genes, 27 transfer RNA genes, and two ribosomal RNA genes. The mitochondrial genome had a base composition of A (39.89%), C (11.06%), G (11.67%), and T (37.38%), with a GC content of 22.73%. A phylogenetic tree based on 22 mitochondrial genomes was constructed, which provided the first insights into the phylogenetic relationships of this species with related boletes. [ABSTRACT FROM AUTHOR]

Introduction: Prunus pedunculata (Prunoideae: Rosaceae), a relic shrub with strong resistance and multiple application values, is endangered in China. Extensive research had been devoted to gene expression, molecular markers, plastid genome analysis, and genetic background investigations of P. pedunculata. However, the mitochondrial genome of this species has not been systematically described, owing to the complexity of the plant mitogenome. Methods: In the present research, the complete mitochondrial genome of P. pedunculata was assembled, annotated, and characterized. The genomic features, gene content and repetitive sequences were analyzed. The genomic variation and phylogenetic analysis have been extensively enumerated. Results and discussion: The P. pedunculata mitogenome is a circular molecule with a total length of 405,855 bp and a GC content of 45.63%, which are the smallest size and highest GC content among the known Prunus mitochondrial genomes. The mitogenome of P. pedunculata encodes 62 genes, including 34 unique protein-coding genes (PCGs, excluding three possible pseudogenes), three ribosomal RNA genes, and 19 transfer RNA genes. The mitogenome is rich in repetitive sequences, counting 112 simple sequence repeats, 15 tandem repeats, and 50 interspersed repetitive sequences, with a total repeat length of 11,793 bp, accounting for 2.91% of the complete genome. Leucine (Leu) was a predominant amino acid in PCGs, with a frequency of 10.67%, whereas cysteine (Cys) and tryptophan (Trp) were the least adopted. The most frequently used codon was UUU (Phe), with a relative synonymous codon usage (RSCU) value of 1.12. Selective pressure was calculated based on 20 shared PCGs in the mitogenomes of the 32 species, most of which were subjected to purifying selection (Ka/Ks < 1), whereas ccmC and ccmFn underwent positive selection. A total of 262 potential RNA editing sites in 26 PCGs were identified. Furthermore, 56 chloroplast-derived fragments were ascertained in the mitogenome, ranging from 30 to 858 bp, and were mainly located across IGS (intergenic spacer) regions or rRNA genes. These findings verify the occurrence of intracellular gene transfer events from the chloroplast to the mitochondria. Furthermore, the phylogenetic relationship of P. pedunculata was supported by the mitogenome data of 30 other taxa of the Rosaceae family. Understanding the mitochondrial genome characteristics of P. pedunculata is of great importance to promote comprehension of its genetic background and this study provides a basis for the genetic breeding of Prunus [ABSTRACT FROM AUTHOR]

Background: Trigonella foenum-graecum L. is a Leguminosae plant, and the stems, leaves, and seeds of this plant are rich in chemical components that are of high research value. The chloroplast (cp) genome of T. foenum-graecum has been reported, but the mitochondrial (mt) genome remains unexplored. Results: In this study, we used second- and third-generation sequencing methods, which have the dual advantage of combining high accuracy and longer read length. The results showed that the mt genome of T. foenum-graecum was 345,604 bp in length and 45.28% in GC content. There were 59 genes, including: 33 protein-coding genes (PCGs), 21 tRNA genes, 4 rRNA genes and 1 pseudo gene. Among them, 11 genes contained introns. The mt genome codons of T. foenum-graecum had a significant A/T preference. A total of 202 dispersed repetitive sequences, 96 simple repetitive sequences (SSRs) and 19 tandem repetitive sequences were detected. Nucleotide diversity (Pi) analysis counted the variation in each gene, with atp6 being the most notable. Both synteny and phylogenetic analyses showed close genetic relationship among Trifolium pratense, Trifolium meduseum, Trifolium grandiflorum, Trifolium aureum, Medicago truncatula and T. foenum-graecum. Notably, in the phylogenetic tree, Medicago truncatula demonstrated the highest level of genetic relatedness to T. foenum-graecum, with a strong support value of 100%. The interspecies non-synonymous substitutions (Ka)/synonymous substitutions (Ks) results showed that 23 PCGs had Ka/Ks < 1, indicating that these genes would continue to evolve under purifying selection pressure. In addition, setting the similarity at 70%, 23 homologous sequences were found in the mt genome of T. foenum-graecum. Conclusions: This study explores the mt genome sequence information of T. foenum-graecum and complements our knowledge of the phylogenetic diversity of Leguminosae plants. [ABSTRACT FROM AUTHOR]

Huperzia crispata is a traditional Chinese herb plant and has attracted special attention in recent years for its products Hup A can serve as an acetylcholinesterase inhibitor (AChEI). Although the chloroplast (cp) genome of H. crispata has been studied, there are no reports regarding the Huperzia mitochondrial (mt) genome since the previously reported H. squarrosa has been revised as Phlegmariurus squarrosus. The mt genome of H. crispata was sequenced using a combination of long-read nanopore and Illumina sequencing platforms. The entire H. crispata mt genome was assembled in a circular with a length of 412,594 bp and a total of 91 genes, including 45 tRNAs, 6 rRNAs, 37 protein-coding genes (PCGs), and 3 pseudogenes. Notably, the rps8 gene was present in P. squarrosus and a pseudogene rps8 was presented in H. crispata, which was lacking in most of Pteridophyta and Gymnospermae. Intron-encoded maturase (mat-atp9i85 and mat-cobi787) genes were present in H. crispata and P. squarrosus, but lost in other examined lycophytes, ferns, and Gymnospermae plants. Collinearity analysis showed that the mt genome of H. crispata and P. squarrossus is highly conservative compared to other ferns. Relative synonymous codon usage (RSCU) analysis showed that the amino acids most frequently found were phenylalanine (Phe) (4.77%), isoleucine (Ile) (4.71%), lysine (Lys) (4.26%), while arginine (Arg) (0.32%), and histidine (His) (0.42%) were rarely found. Simple sequence repeats (SSR) analysis revealed that a total of 114 SSRs were identified in the mt genome of H. crispata and account for 0.35% of the whole mt genome. Monomer repeats were the majority types of SSRs and represent 91.89% of the total SSRs. In addition, a total of 1948 interspersed repeats (158 forward, 147 palindromic, and 5 reverse repeats) with a length ranging from 30 bp to 14,945 bp were identified in the H. crispata mt genome and the 30–39-bp repeats were the most abundant type. Gene transfer analysis indicated that a total of 12 homologous fragments were discovered between the cp and mt genomes of H. crispata, accounting for 0.93% and 2.48% of the total cp and mt genomes, respectively. The phylogenetic trees revealed that H. crispata was the sister of P. squarrosus. The Ka/Ks analysis results suggested that most PCGs, except atp6 gene, were subject to purification selection during evolution. Our study provides extensive information on the features of the H. crispata mt genome and will help unravel evolutionary relationships, and molecular identification within lycophytes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Cork oak (Quercus suber L.) is an ecologically and economically important evergreen tree species native to the Mediterranean region and widespread in southwest Europe and northwest Africa. An improved genome assembly of cork oak using a combination of Illumina and PacBio sequencing is presented in this study. The assembled genome contains 2351 scaffolds longer than 1000 bp, accounting for 765.7 Mbp of genome size, L90 of 755, and a N50 of 1.0 Mbp, with 40,131 annotated genes. The repetitive sequences constitute 53.6% of the genome. The genome sequences of chloroplast and mitochondrion were determined for the first time, with a genome size of 161,179 bp and 531,858 bp, respectively. Phylogenetic analysis based on complete chloroplast genome sequence showed that Q. suber is closely related to Quercus variabilis, two cork-producing species with commercial use. All data generated are available through the public databases, being ready to be used without restrictions. This study provides an improved nuclear genome assembly together with the organelle genomes of cork oak. These resources will be useful for further breeding strategies and conservation programs and for comparative genomic studies in oak species. [ABSTRACT FROM AUTHOR]

Background: Rhinogobio nasutus, an endemic species from the Yellow River, is listed under the second class of the National Key Protected Wildlife List in China due to its dramatically decreased population. Despite its important status, the mitochondrial genes and phylogenetic relationships of R. nasutus are unknown. Methods and Results: The complete mitochondrial genome of R. nasutus was sequenced, assembled, and annotated for the first time. The mitochondrial genome was 16,609 bp in length, consisting of 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and 1 non-coding control region. The gene order in the mitochondrial genome of R. nasutus was identical to that of other Rhinogobios species. Analysis of synonymous and non-synonymous nucleotide substitutions showed that the Ka/Ks ratio in all tested protein-coding genes was less than 1, indicating that these genes were evolving under purifying selection. Further phylogenetic analysis showed that R. nasutus was first clustered with R. typus, then grouped with the other two Rhinogobio species, indicating the phylogenetically close relationship between R. nasutus and R. typus. Conclusions: This was the first genomic resource developed for R. nasutus, which could not only improve our understanding of its phylogenetic status, but also serve as a genomic tool for the development of genetic markers that will be used in conservation and evolutionary genetics studies. [ABSTRACT FROM AUTHOR]

Symbiochlorum hainanensis Gong et al. (2018). is a unicellular green alga belonging to Ulvophyceae, Chlorophyta, and considered as an important species in coral-algae symbiont areas. In this study, we revealed firstly the mitochondrial genome sequence of the S. hainanensis. This mitochondrial genome was a circular DNA molecule of 59,508 bp, including 24 transfer RNA genes, 3 ribosomal RNA genes, and 31 protein-coding genes. The GC content of the genome was 35.4%. The phylogenetic tree suggested that S. hainandiae was a sister to the OUU clade within the class Ulvophyceae. The mitochondrial genome structure and gene content of S. hainanensis supported that S. hainanensis was a new unidentified green alga in Ulvophyceae. [ABSTRACT FROM AUTHOR]

We used the Illumina MiSeq platform to sequence the complete mitochondrial genome of Triplophysa jianchuanensis (Cypriniformes: Cobitidae). The mitochondrial genome of T. jianchuanensis is 16,569 bp in length, and its genetic constitution and arrangement are consistent with those of the teleost taxon, containing 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, an origin of light-strand replication, and a control region. The overall nucleotide base composition was 28.33% A, 27.25% T, 17.77% G, and 26.65% C. Phylogenetic analysis showed that T. jianchuanensis was grouped with T. venusta. These findings are valuable for further studies on the evolution, genetic diversity, and taxonomy of Triplophysa. [ABSTRACT FROM AUTHOR]

Simple Summary: Typhlocybinae is the second-largest subfamily in the leafhopper family Cicadellidae, comprising approximately 6000 valid species worldwide. Typholocybinae has been divided into six tribes. Typhlocybini and Zyginellini were distinguished only based on one character of the hind wing venation, and the latter tribe was recently considered to be a junior synonym of the former, but few mitogenome sequences representative of major lineages of Typhlocybini have been available to facilitate a comprehensive phylogenetic analysis of the tribe. Thus, we performed complete mitogenome sequencing and functional annotations for 19 species of Typhlocybinae, combining them with 48 mitogenome sequences of previously available typhlocybine mitogenomes to reconstruct phylogenetic relationships with the main lineages to examine the monophyly of Typhlocybini and the phylogenetic status and relationships among generic complexes. The results confirm that Zyginellini should be treated as a junior synonym of Typhlocybini, and some generic groups previously recognized based on morphological characters correspond to monophyletic lineages. Tribes of the leafhopper subfamily Typhlocybinae have traditionally been defined based on differences in forewing and hindwing venation. Except for Typhlocybini (sensu lato), the classification of tribes is relatively stable. The monophyly of Typhlocybini needs to be examined, and the relationships among genera within Typhlocybini have not been resolved. Few mitogenome sequences representative of major lineages of Typhlocybini have been available to facilitate a comprehensive phylogenetic analysis of the tribe. In this study, the complete mitogenomes of 19 species of Typhlocybini were sequenced. The gene arrangements of the 19 new mitogenomes are consistent with ancestral insect mitogenomes. Phylogenetic analyses by both maximum-likelihood and Bayesian methods of 67 species of Typhlocybinae suggest that Zyginellini is paraphyletic with respect to Typhlocybini. The phylogenetic relationships within Typhlocybini are discussed, and the major results show that the Farynala and Linnavuoriana complexes previously recognized based on morphological characters correspond to monophyletic lineages. [ABSTRACT FROM AUTHOR]

The green sawfish Pristis zijsron (Bleeker, 1851), a species of sawfish in the family Pristidae (Rhinopristiformes), mainly inhabits the Indo-West Pacific region. In this study, the complete mitochondrial genome of the critically endangered green sawfish is first described. The length of the genome is 16,804 bp, with a nucleotide composition of 32.0% A, 24.8% C, 13.1% G, and 30.0% T. It contains 37 genes in the typical gene order of fish. Two start (GTG and ATG) and two stop (TAG and TAA/T-) codons are found in the thirteen protein-coding genes. The 22 tRNA genes range from 67 bp (tRNA-Ser) to 75 bp (tRNA-Leu). The ratio of nonsynonymous substitution (Ka) and synonymous substitution (Ks) indicates that the family Pristidae are suffering a purifying selection. The reconstruction of Bayesian inference and the maximum likelihood phylogenetic tree show the same topological structure, and the family Pristidae is a monophyletic group with strong posterior probability. Pristis zijsron and P. pectinata form a sister group in the terminal clade. And the divergence time of Rhinopristiformes show that P. zijsron and P. pectinata diverged as two separate species in about Paleogene 31.53 Mya. Complete mitochondrial genomes of all five sawfishes have been published and phylogenetic relationships have been analyzed. The results of our study will provide base molecular information for subsequent research (e.g., distribution, conservation, phylogenetics, etc.) on this endangered group. [ABSTRACT FROM AUTHOR]

Pseudofabraea citricarpa (Dermateaceae: Helotiales) is known as a significant pathogen causing Citrus target spot disease and results in profound yield loss. In the present study, the complete mitochondrial genome (mitogenome) determined based on next-generation sequencing technology. The circular mitogenome (56,935 bp) comprised 14 conserved protein-coding genes (PCGs), 16 ORFs, two ribosomal RNA genes (rns and rnl), one non-coding RNA gene (rnpB), one ribosomal protein S3 (rps3) and 28 transfer RNA (tRNA) genes. The overall base composition is as follows: 36.08% A, 35.25% T, 13.04% C, and 15.63% G, with a GC content of 28.70%. The phylogenetic analysis shows that P. citricarpa, belonging to Dermateaceae, forms a separate clade and is sister to Sclerotiniaceae. The mitogenome of P. citricarpa reported in this study provides more molecular data for further research on the evolutionary relationships of Helotiales. [ABSTRACT FROM AUTHOR]

We assembled the complete mitochondrial genome (mitogenome) of Mastigias papua (Scyphozoa: Rhizostomeae: Mastigiidae) by the data generated from the next-generation sequencing platform. The complete mitogenome of M. papua was 16,560 bp in length, containing 14 protein-coding genes, two transfer RNA genes, and two ribosomal RNA genes. The base compositions were A 30.65%, C 15.16%, G 16.34%, and T 37.86%, with a gene arrangement similar to the mitogenomes derived from other representatives of Scyphozoa. Based on the 13 common protein-coding genes of 16 species within Scyphozoa, we constructed the phylogenetic tree and found that M. papua has a close relationship with Cassiopea andromeda and Cassiopea xamachana. All these species belong to an order of jellyfish Rhizostomeae, which have similar morphological characteristics. This is agreement with the conclusion we got by the phylogenetic relationship analysis using molecular data. This research has practical implications for advancing understanding of the phylogenetic relationships, taxonomic classifications, and phylogeography within Scyphozoa. [ABSTRACT FROM AUTHOR]

Alcichthys elongatus is the only species in the genus, and this work is the first to provide a comprehensive mitogenome analysis of this species. The A. elongatus mitogenome was 16,712 bp long, with biased A + T content (52.33%), and featured thirteen protein-coding genes (PCGs), twenty-two tRNAs, two rRNAs, and the control region (D-loop). The H strand encoded twenty-eight genes (twelve PCGs, fourteen tRNA, and two rRNA) and the control region, whereas the L strand encoded the remaining nine genes (ND6 and eight tRNA). Except for COXI, which started with GTG, all PCG sequences started with ATG and ended with TAA (ND4L, ND5, COXI, ATP8) or TAG (ND1, ND6) termination codons, with some (ND2, ND3, ND4, COXII, COXIII, ATP6, Cytb) having an incomplete termination codon. Except for tRNA-serine-1 (trnS), the majority of the tRNAs exhibited characteristic cloverleaf secondary structures. Based on 13 PCGs, phylogenetic analysis placed A. elongatus in the same clade as Icelus spatula. This genomic data will be useful for species identification, phylogenetic analysis, and population genetics. [ABSTRACT FROM AUTHOR]