In silico analysis of the wheat BBX gene family and identification of candidate genes for seed dormancy and germination.

BACKGROUND: B-box (BBX) proteins are a type of zinc finger proteins containing one or two B-box domains. They play important roles in development and diverse stress responses of plants, yet their roles in wheat remain unclear. RESULTS: In this study, 96 BBX genes were identified in the wheat genome and classified into five subfamilies. Subcellular localization prediction results showed that 68 TaBBXs were localized in the nucleus. Protein interaction prediction analysis indicated that interaction was one way that these proteins exerted their functions. Promoter analysis indicated that TaBBXs may play important roles in light signal, hormone, and stress responses. qRT-PCR analysis revealed that 14 TaBBXs were highly expressed in seeds compared with other tissues. These were probably involved in seed dormancy and germination, and their expression patterns were investigated during dormancy acquisition and release in the seeds of wheat varieties Jing 411 and Hongmangchun 21, showing significant differences in seed dormancy and germination phenotypes. Subcellular localization analysis confirmed that the three candidates TaBBX2-2 A, TaBBX4-2 A, and TaBBX11-2D were nuclear proteins. Transcriptional self-activation experiments further demonstrated that TaBBX4-2A was transcriptionally active, but TaBBX2-2A and TaBBX11-2D were not. Protein interaction analysis revealed that TaBBX2-2A, TaBBX4-2A, and TaBBX11-2D had no interaction with each other, while TaBBX2-2A and TaBBX11-2D interacted with each other, indicating that TaBBX4-2A may regulate seed dormancy and germination by transcriptional regulation, and TaBBX2-2A and TaBBX11-2D may regulate seed dormancy and germination by forming a homologous complex. CONCLUSIONS: In this study, the wheat BBX gene family was identified and characterized at the genomic level by bioinformatics analysis. These observations provide a theoretical basis for future studies on the functions of BBXs in wheat and other species.

The complete chloroplast genome of Mussaenda pubescens and phylogenetic analysis.

The chloroplast (cp) genome sequence of Mussaenda pubescens, a promising resource that is used as a traditional medicine and drink, is important for understanding the phylogenetic relationships among the Mussaenda family and genetic improvement and reservation. This research represented the first comprehensive description of the morphological characteristics of M. pubescens, as well as an analysis of the complete cp genome and phylogenetic relationship. The results indicated a close relationship between M. pubescens and M. hirsutula based on the morphological characteristics of the flower and leaves. The cp was sequenced using the Illumina NovaSeq 6000 platform. The results indicated the cp genome of M. pubescens spanned a total length of 155,122 bp, including a pair of inverted repeats (IRA and IRB) with a length of 25,871 bp for each region, as well as a large single-copy (LSC) region and a small single-copy (SSC) region with lengths of 85,370 bp and 18,010 bp, respectively. The results of phylogenetic analyses demonstrated that species within the same genus displayed a tendency to group closely together. It was suggested that Antirhea, Cinchona, Mitragyna, Neolamarckia, and Uncaria might have experienced an early divergence. Furthermore, M. hirsutula showed a close genetic connection to M. pubescens, with the two species having partially overlapping distributions in China. This study presents crucial findings regarding the identification, evolution, and phylogenetic research on Mussaenda plants, specifically targeting M. pubescens.

The complete chloroplast genome sequence and phylogenetic relationship analysis of Eomecon chionantha, one species unique to China.

Eomecon chionantha Hance, an endemic species in China, has a long medical history in Chinese ethnic minority medicine and is known for its anti-inflammatory and analgesic effects. However, studies of E. chionantha are lacking. In this study, we investigated the characteristics of the E. chionantha chloroplast genome and determined the taxonomic position of E. chionantha in Papaveraceae via phylogenetic analysis. In addition, we determined molecular markers to identify E. chionantha at the molecular level by comparing the chloroplast genomes of E. chionantha and its closely related species. The complete chloroplast genomic information indicated that E. chionantha chloroplast DNA (178,808 bp) contains 99 protein-coding genes, 8 rRNAs, and 37 tRNAs. Meanwhile, we were able to identify a total of 54 simple sequence repeats through our analysis. Our findings from the phylogenetic analysis suggest that E. chionantha shares a close relationship with four distinct species, namely Macleaya microcarpa, Coreanomecon hylomeconoides, Hylomecon japonica, and Chelidonium majus. Additionally, using the Kimura two-parameter model, we successfully identified five hypervariable regions (ycf4-cemA, ycf3-trnS-GGA, trnC-GCA-petN, rpl32-trnL-UAG, and psbI-trnS-UGA). To the best of our knowledge, this is the first report of the complete chloroplast genome of E. chionantha, providing a scientific reference for further understanding of E. chionantha from the perspective of the chloroplast genome and establishing a solid foundation for the future identification, taxonomic determination and evolutionary analysis of this species.

Comparative Analysis of the Complete Mitochondrial Genomes of Three Sisoridae (Osteichthyes, Siluriformes) and the Phylogenetic Relationships of Sisoridae.

The family Sisoridae is one of the largest and most diverse Asiatic catfish families, with most species occurring in the water systems of the Qinhai-Tibetan Plateau and East Himalayas. At present, the phylogenetic relationship of the Sisoridae is relatively chaotic. In this study, the mitochondrial genomes (mitogenomes) of three species Creteuchiloglanis kamengensis, Glaridoglanis andersonii, and Exostoma sp. were systematically investigated, the phylogenetic relationships of the family were reconstructed and to determine the phylogenetic position of Exostoma sp. within Sisoridae. The lengths of the mitogenomes' sequences of C. kamengensis, G. andersonii, and Exostoma sp. were 16,589 bp, 16,531 bp, and 16,529 bp, respectively. They all contained one identical control region (D-loop), two ribosomal RNAs (rRNAs), 13 protein-coding genes (PCGs) and 22 transfer RNA (tRNA) genes. We applied two approaches, Bayesian Inference (BI) and Maximum Likelihood (ML), to construct phylogenetic trees. Our findings revealed that the topological structure of both ML and BI trees exhibited significant congruence. Specifically, the phylogenetic tree strongly supports the monophyly of Sisorinae and Glyptosternoids and provides new molecular biological data to support the reconstruction of phylogenetic relationships with Sisoridae. This study is of great scientific value for phylogenetic and genetic variation studies of the Sisoridae.

Comparative Genomics Reveal Phylogenetic Relationship and Chromosomal Evolutionary Events of Eight Cervidae Species.

Cervidae represents a family that is not only rich in species diversity but also exhibits a wide range of karyotypes. The controversies regarding the phylogeny and classification of Cervidae still persist. The flourishing development of the genomic era has made it possible to address these issues at the genomic level. Here, the genomes of nine species were used to explore the phylogeny and chromosomal evolutionary events of Cervidae. By conducting whole-genome comparisons, we identified single-copy orthologous genes across the nine species and constructed a phylogenetic tree based on the single-copy orthologous genes sequences, providing new insights into the phylogeny of Cervidae, particularly the phylogenetic relationship among sika deer, red deer, wapiti and Tarim red deer. Gene family analysis revealed contractions in the olfactory receptor gene family and expansions in the histone gene family across eight Cervidae species. Furthermore, synteny analysis was used to explore the chromosomal evolutionary events of Cervidae species, revealing six chromosomal fissions during the evolutionary process from Bovidae to Cervidae. Notably, specific chromosomal fusion events were found in four species of Cervus, and a unique chromosomal fusion event was identified in Muntiacus reevesi. Our study further completed the phylogenetic relationship within the Cervidae and demonstrated the feasibility of inferring species phylogeny at the whole-genome level. Additionally, our findings on gene family evolution and the chromosomal evolutionary events in eight Cervidae species lay a foundation for comprehensive research of the evolution of Cervidae.

The complete chloroplast genome assembly of Commelina caroliniana Walter (Commelinaceae).

We sequenced and published the chloroplast genome of Commelina caroliniana Walter, which was previously misidentified as C. diffusa owing to their morphological similarities until 1989. The genome of C. caroliniana is 160,857 bp long [large single copy region: 88,064 bp; a small single copy region: 18,549 bp; two inverted repeat regions: 27,122 bp] and has a GC content of 35.7%. The genome comprises 133 genes, including 87 coding sequences (CDSs), 38 tRNAs, and eight rRNAs. The phylogenetic relationship between C. caroliniana and related species was analyzed using the maximum likelihood method based on the 79 CDSs of the chloroplast genome. Phylogenetic analysis revealed that C. caroliniana is closely related to C. communis. Our findings will contribute to studies on species identification and phylogenetic and evolutionary research. These results enhance our understanding of the Commelina genus.

Rediscovering the unusual, solitary bryozoan Monobryozoon ambulans Remane, 1936: first molecular and new morphological data clarify its phylogenetic position.

BACKGROUND: One of the most peculiar groups of the mostly colonial phylum Bryozoa is the taxon Monobryozoon, whose name already implies non-colonial members of the phylum. Its peculiarity and highly unusual lifestyle as a meiobenthic clade living on sand grains has fascinated many biologists. In particular its systematic relationship to other bryozoans remains a mystery. Despite numerous searches for M. ambulans in its type locality Helgoland, a locality with a long-lasting marine station and tradition of numerous courses and workshops, it has never been reencountered until today. Here we report the first observations of this almost mythical species, Monobryozoon ambulans. RESULTS: For the first time since 1938, we present new modern, morphological analyses of this species as well as the first ever molecular data. Our detailed morphological analysis confirms most previous descriptions, but also ascertains the presence of special ambulatory polymorphic zooids. We consider these as bud anlagen that ultimately consecutively separate from the animal rendering it pseudo-colonial. The remaining morphological data show strong ties to alcyonidioidean ctenostome bryozoans. Our morphological data is in accordance with the phylogenomic analysis, which clusters it with species of Alcyonidium as a sister group to multiporate ctenostomes. Divergence time estimation and ancestral state reconstruction recover the solitary state of M. ambulans as a derived character that probably evolved in the Late Cretaceous. In this study, we also provide the entire mitogenome of M. ambulans, which-despite the momentary lack of comparable data-provides important data of a unique and rare species for comparative aspects in the future. CONCLUSIONS: We were able to provide first sequence data and modern morphological data for the unique bryozoan, M. ambulans, which are both supporting an alcyonidioidean relationship within ctenostome bryozoans.

Extensive Countrywide Molecular Identification and High Genetic Diversity of Haemonchus spp. in Domestic Ruminants in Greece.

The gastrointestinal nematode parasite Haemonchus spp. is one of the most pathogenic parasites of ruminants, due to its blood-sucking activity, which causes large economic losses in the ruminant industry. The latest epizootiological data recorded an increase in the infection, not only in Greece but also in other countries, mainly attributed to climatic changes. The study of the population structure and the investigation of the phylogenetic relationships of Haemonchus spp. are essential for the understanding of its biology and epizootiology to implement appropriate control and prevention strategies. In addition, the molecular approach allows the determination of evolutionary relationships between different species of this parasite, the diverse hosts they infect, as well as the different geographic compartments from which they originate. Therefore, the aim of the present study was to identify the species of the sympatric populations of the genus Haemonchus, a nematode parasite infecting ruminants (sheep, goats, cattle, and buffaloes) from different regions of Greece (continental and insular) using molecular methods. At the same time, an attempt was made to identify the possible subpopulations of Haemonchus spp. in Greece, to investigate their phylogenetic relationships, as well as to determine the genetic diversity of each population. A total of 288 worms of the genus Haemonchus were processed using molecular methods; of these, 96 were collected from sheep, 96 from goats, 48 from cattle, and finally, 48 from buffaloes. A fragment of 321 base pairs of the second internal transcribed spacer (ITS2) sequence of nuclear DNA was amplified for species identification, and, after basic local alignment search tool (Blast) analysis, it was revealed that they belonged to H. contortus. A fragment of 820 base pairs of subunit 4 of the nicotinamide dehydrogenase (ND4) gene of mitochondrial DNA was amplified for genetic diversity analysis. The Greek mitochondrial ND4 sequences of H. contortus were classified into 140 haplotypes, and the values of the average nucleotide and haplotype diversity were lower compared to the respective values derived from Italy, Malaysia, the USA, and China. The phylogenetic analysis of the ND4 gene revealed a clear grouping of the Greek haplotypes when compared with Asian ones, and, at the same time, there was no profound grouping of the same haplotypes with regard to their different hosts and geographical origin within different regions of Greece. The aforementioned findings confirmed that H. contortus prevails in our country and can infect all species of ruminants, without geographical boundaries, when the right conditions (i.e., common grazing) are created.

Molecular Characterization and Phylogenetic Analysis of Flightin Gene in Vespa basalis (Hymenoptera, Vespidae).

Flight is a complex physiological process requiring precise coordination of muscular contraction. A key protein in insect flight is flightin, which plays an integral role in the flight muscles. This research sought to evaluate the flight competence of the social wasp V. basalis by characterizing the molecular components involved. Our study focused on Vespa basalis, one of the most dangerous hornet species, utilizing PCR to obtain a partial cDNA sequence of the flightin protein. We then employed phylogenetic and sequence analysis to gain insights into this protein in flight-related adaptations. The cDNA has an 1189-base pair sequence including an open reading frame (453 bp) encoding 150 amino acids. Analyzing the deduced amino acid sequence using an online tool revealed a molecular weight of 18.05 kDa, an isoelectric point of 5.84, four functional site patterns, and no transmembrane topology. We constructed a phylogenetic tree of flightin based on 38 species. Our analysis indicated that V. basalis is most closely related to V. mandarinia; this alignment is consistent with their similar aggressive behavior, but their evolutionary relationship, based on mitochondrial sequences, presents a contrast. These initial findings on the flightin gene in V. basalis lay the groundwork for future functional studies to elucidate its specific role in flight adaptations and explore its potential as a target for pest management strategies.

The complete mitochondrial genome of cattle tick clade C reveals the genetic relationship within Rhipicephalus microplus complex.

Cattle ticks (Rhipicephalus microplus) are important economic ectoparasites causing direct and indirect damage to cattle and leading to severe economic losses in cattle husbandry. It is common knowledge that R. microplus is a species complex including five clades; however, the relationships within the R. microplus complex remain unresolved. In the present study, we assembled the complete mitochondrial genome of clade C by next-generation sequencing and proved its correctness based on long PCR amplification. It was 15,004 bp in length and consisted of 13 protein genes, 22 transfer genes, and two ribosomal genes located in the two strains. There were two copies of the repeat region (pseudo-nad1 and tRNA-Glu). Data revealed that cox1, cox2, and cox3 genes were conserved within R. microplus with small genetic differences. Ka/Ks ratios suggested that 12 protein genes (excluding nad6) may be neutral selection. The genetic and phylogenetic analyses indicated that clade C was greatly close to clade B. Findings in the current study provided more data for the identification and differentiation of the R. microplus complex and made up for the lack of information about R. microplus clade C.

The complete chloroplast genome sequence of Myricaria wardii Marquand 1929 (Tamaricaceae): a shrub species endemic to the Tibet Plateau.

Myricaria wardii Marquand 1929, endemic to the Tibet Plateau, is a perennial shrub with important medicinal and ecological values. In this study, the complete chloroplast (cp) genome of M. wardii was assembled, and the phylogenetic tree was reconstructed to evaluate the phylogenetic location of the species. The results showed that the cp genome size of the M. wardii was 155,299 bp, which contained a pair of inverted repeat (IR) regions (26,150 bp), a large single copy (LSC) region (84,715 bp), and a small single copy (SSC) region (18,284 bp). The total GC content of the cp genome was 36.30%. A total of 128 genes were annotated, consisting of 83 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The phylogenetic analysis showed that M. wardii was closely related to M. prostrata. This study provides useful information for the conservation of this species and the phylogenetic analysis of Tamaricaceae.

The complete chloroplast genome of Nekemias hypoglauca (Hance) J. Wen & Z. L. Nie 2014 (Family: Vitaceae) and its phylogenetic analysis.

Nekemias is a perennial woody vine with nine species that had been originally placed in Ampelopsis. These species of Nekemias are economically and medically important. Limited information is available on the genomic characteristics of the chloroplasts of this genus. Nekemias hypoglauca (Hance) J. Wen & Z. L. Nie 2014 contains 131 unique genes (86 protein-coding genes, 8 rRNAs, and 37 tRNAs). The complete chloroplast sequence contains 162,976 bp. The large single-copy region contains 89,291 bp; the small single-copy region contains 19,063 bp, and a pair of inverted repeat sequences is composed of 27,311 bp. There are 84 simple sequence repeat (SSR) loci in the complete chloroplast genome of N. hypoglauca, with mononucleotide, dinucleotide, trinucleotide, tetranucleotide and hexanucleotide SSRs of 58, 9, 6, 10 and 1, respectively. A total of 337 repeats were identified, including 172 forward repeats, three reverse repeats and 163 palindromic repeats. A phylogenetic analysis based on the complete genome data of the chloroplasts of 10 plant species indicated the monophyly of Nekemias and determined the phylogenetic relationships of N. hypoglauca in Nekemias. This study provides a reference for further studies on the taxonomy, identification, origin and evolution of N. hypoglauca and Nekemias.

Comprehensive Analysis of Phylogenetic Relationship and Optimal Codons in Mitochondrial Genomes of the Genus Pseudogastromyzon.

As indicator organisms for water pollution detection, Pseudogasteromyzon species play a vital role in aquatic environment monitoring. We have successfully sequenced the mitogenomes of P. fasciatus jiulongjiangensis and P. myersi and downloaded the mitogenomes of nine other Pseudogastromyzon fish on GenBank to conduct a detailed comparative analysis of their phylogenetic relationships and evolutionary history. The findings revealed a conservation in both gene composition and gene order. Except for the trnS1 gene lacking dihydrouracil arms, the other 21 tRNAs showed the typical clover-leaf secondary structure. According to the ΔRSCU method, we identified the seven most abundant optimal codons: CUA, GUA, CCA, CAA, GAA, AGC, and GGC. The construction of maximum parsimony, maximum likelihood, and Bayes trees yielded congruent topologies, and the 11 Pseudogastromyzon species were clustered into two major clusters. Among them, one of which was composed of P. fangi, P. changtingensis changtingensis, and P. changtingensis tungpeiensis, while the remaining eight species formed another cluster, further subdivided into five smaller clusters. Distinct clusters formed between P. fasciatus jiulongjiangensis and P. meihuashanensis, P. cheni and P. peristictus, and P. laticeps and P. lianjiangensis, and the remaining two species were clustered separately, thereby enhancing our understanding of them. Furthermore, our analysis results of divergence times revealed that these 11 Pseudogasteromyzon species underwent rapid differentiation in the Pleistocene epochs. Overall, our study sheds light on the phylogenetic relationship and evolutionary history of Pseudogasteromyzon species, providing a necessary knowledge foundation for further understanding the intricacies of an ecosystem health assessment.

The P2 nucleic acid binding protein of Sugarcane bacilliform virus is a viral pathogenic factor.

Background: Saccharum spp. is the primary source of sugar and plays a significant role in global renewable bioenergy. Sugarcane bacilliform virus (SCBV) is one of the most important viruses infecting sugarcane, causing severe yield losses and quality degradation. It is of great significance to reveal the pathogenesis of SCBV and resistance breeding. However, little is known about the viral virulence factors or RNA silencing suppressors and the molecular mechanism of pathogenesis. Methods: To systematically investigate the functions of the unknown protein P2 encoded by SCBV ORF2. Phylogenetic analysis was implemented to infer the evolutionary relationship between the P2 of SCBV and other badnaviruses. The precise subcellular localization of P2 was verified in the transient infiltrated Nicotiana benthamiana epidermal mesophyll cells and protoplasts using the Laser scanning confocal microscope (LSCM). The post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) RNA silencing suppressor activity of P2 was analyzed, respectively. Furthermore, restriction digestion and RT-qPCR assays were conducted to verify the probable mechanism of P2 on repressing DNA methylation. To explore the pathogenicity of P2, a potato virus X-based viral vector was used to heterologously express SCBV P2 and the consequent H2O2 accumulation was detected by the 3,3'-diaminobenzidine (DAB) staining method. Results: Phylogenetic analysis shows that SCBV has no obvious sequence similarity and low genetic relatedness to Badnavirus and Tungrovirus representatives. LSCM studies show that P2 is localized in both the cytoplasm and nucleus. Moreover, P2 is shown to be a suppressor of PTGS and TGS, which can not only repress ssRNA-induced gene silencing but also disrupt the host RNA-directed DNA methylation (RdDM) pathway. In addition, P2 can trigger an oxidative burst and cause typical hypersensitive-like response (HLR) necrosis in systemic leaves of N. benthamiana when expressed by PVX. Overall, our results laid a foundation for deciphering the molecular mechanism of SCBV pathogenesis and made progress for resistance breeding.

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.

Complete Chloroplast Genomes of Four Oaks from the Section Cyclobalanopsis Improve the Phylogenetic Analysis and Understanding of Evolutionary Processes in the Genus Quercus.

Quercus is a valuable genus ecologically, economically, and culturally. They are keystone species in many ecosystems. Species delimitation and phylogenetic studies of this genus are difficult owing to frequent hybridization. With an increasing number of genetic resources, we will gain a deeper understanding of this genus. In the present study, we collected four Quercus section Cyclobalanopsis species (Q. poilanei, Q. helferiana, Q. camusiae, and Q. semiserrata) distributed in Southeast Asia and sequenced their complete genomes. Following analysis, we compared the results with those of other species in the genus Quercus. These four chloroplast genomes ranged from 160,784 bp (Q. poilanei) to 161,632 bp (Q. camusiae) in length, with an overall guanine and cytosine (GC) content of 36.9%. Their chloroplast genomic organization and order, as well as their GC content, were similar to those of other Quercus species. We identified seven regions with relatively high variability (rps16, ndhk, accD, ycf1, psbZ-trnG-GCC, rbcL-accD, and rpl32-trnL-UAG) which could potentially serve as plastid markers for further taxonomic and phylogenetic studies within Quercus. Our phylogenetic tree supported the idea that the genus Quercus forms two well-differentiated lineages (corresponding to the subgenera Quercus and Cerris). Of the three sections in the subgenus Cerris, the section Ilex was split into two clusters, each nested in the other two sections. Moreover, Q. camusiae and Q. semiserrata detected in this study diverged first in the section Cyclobalanopsis and mixed with Q. engleriana in the section Ilex. In particular, 11 protein coding genes (atpF, ndhA, ndhD, ndhF, ndhK, petB, petD, rbcL, rpl22, ycf1, and ycf3) were subjected to positive selection pressure. Overall, this study enriches the chloroplast genome resources of Quercus, which will facilitate further analyses of phylogenetic relationships in this ecologically important tree genus.

Novel insights into adaptive evolution based on the unusual AT-skew in Acheilognathus gracilis mitogenome and phylogenetic relationships of bitterling.

Acheilognathus gracilis, a bitterling species, distribute in lower reaches of Yangtze River. They are identified as the top-priority bitterling species for conservation as having high evolutionary distinctiveness and are at risk of extinction. In present study, we first sequenced the complete mitogenome of A. gracilis and analyzed its phylogenetic position using 13 PCGs. The A. gracilis mitogenome is 16,774 bp in length, including 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, a control region and the origin of the light strand replication. The overall base composition of A. gracilis in descending order is T 27.9 %, A 27.7 %, C 26.1 % and G 18.3 %, shows a unusual AT-skew with slightly negative. Further investigation revealed A. gracilis uses excess T over A in NADH dehydrogenase 5 (nd5), whereas the most of other bitterlings are biased toward to use A not T, implying there is likely to be unique strategy of adaptive evolution in A. gracilis. We also compared 13 PCGs of 30 bitterling mitogenomes and the results exhibit highly conservative. Phylogenetic trees constructed by 13 PCGs strongly support the monophyly of Acheilognathus and the paraphyly of Rhodeus and Tanakia. Current results will provide valuable information for follow-up research on conservation of species facing with serious population decline and can provide novel insights into the phylogenetic analysis and evolutionary biology research.

The complete chloroplast genome of Chrysoglossum ornatum (Epidendroideae, Orchidaceae) and its phylogenetic analysis.

Chrysoglossum ornatum Blume, the type species of Chrysoglossum Blume, belongs to the tribe Collabieae of the subfamily Epidendroideae of Orchidaceae. In this study, we sequenced, assembled, and analyzed the complete chloroplast genome of C. ornatum. The result showed that the complete chloroplast genome of C. ornatum was 158,175 bp in size, consisting of a large single-copy (LSC) region of 87,235 bp, a small single-copy (SSC) region of 18,384 bp, and a pair of inverted repeats (IRs) of 26,278 bp. The chloroplast genome encoded 113 unique genes, comprising 80 protein-coding genes, 29 tRNA genes, and four rRNA genes. Phylogenetic analysis inferred from the complete chloroplast genome indicated that Chrysoglossum was closely related to Collabium Blume. This study provides genomic resources helpful for further phylogenetic and biodiversity research on Chrysoglossum.

Characterization and phylogenetic analysis of the chloroplast genome of Duhaldea cappa (Buch.-Ham. ex D.Don) Pruski & Anderb. (Asteraceae).

Duhaldea cappa, a valuable medicinal plant of genus Duhaldea in the tribe Inuleae, is predominantly found in China, Bhutan, India, Malaysia, Nepal, Pakistan, Thailand, and Vietnam. However, the genomic studies of Duhaldea cappa are limited. In this study, we successfully sequenced and assembled the complete chloroplast genome of Duhaldea cappa. The chloroplast genome is 150,819 bp in length with a 37.73% GC content. The chloroplast genome has a quadripartite structure, consisting of a large single-copy region of 82,731 bp, a small single-copy region of 18,168 bp, and a pair of inverted repeat sequences of 24,960 bp. The genome contains 133 genes. Among these genes, there are 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogeny reconstructed from data of the complete chloroplast genome indicated that Duhaldea cappa is closely related to Pluchea indica in the tribe Inuleae. Analyzing and reporting the chloroplast genome of Duhaldea cappa will establish a solid theoretical and data foundation for the efficient development, conservation, and utilization of this plant species.

The complete mitochondrial genome of Siganus virgatus Valenciennes (Siganidae: Acanthuriformes).

Siganus virgatus Valenciennes 1835 is an essential species for examining reef ecosystems; however, its mitochondrial genome has not been studied. In this research, the mitogenome of S. virgatus was sequenced and characterized. The results revealed a circular genome of 16,505 bp that was composed of A (28.1%), C (31.3%), G (14%), and T nucleotides (26.6%). The genome contained 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. Most genes of the mitogenome were transcribed on the heavy strand (H-strand), whereas ND6 and eight tRNA genes (including tRNA-Ala, -Asn, -Cys, -Gln, -Glu, -Ser (1), -Pro, and -Tyr) were transcribed on the light strand (L-strand). Comparative analysis revealed a high degree of conservation of gene content and order among the Siganus mitogenomes. Phylogenetic analysis inferred from whole mitogenomes exhibited a close relationship between S. virgatus and S. guttatus. The newly completed mitogenome of S. virgatus provides essential genomic data for further studies on population genetics and the evolution of the Siganus genus and the Siganidae family.