Genetic diversity and structure of Persicaria amphibia (Polygonaceae) in South Korea using genotyping by sequencing.

BACKGROUND: Persicaria amphibia, a member of the Polygonaceae family, exists both aquatic and terrestrial forms. It is native to North America, Asia, Europe, and some parts of Africa. OBJECTIVE: This study aimed to determine the genetic diversity within and among populations of P. amphibia and the distribution characteristics of each population to investigate insights into the genetic structure and conservation of P. amphibia. METHODS: In this study, the genetic diversity and structure of 84 P. amphibia individuals from 7 populations in South Korea were analyzed using genotyping-by-sequencing (GBS). We used 2,469 single nucleotide polymorphisms (SNPs) to analyze genetic diversity, principal components, structure, and phylogeny. RESULTS: Our results showed a mean observed heterozygosity and mean expected heterozygosity of 0.34409 and 0.34082, respectively. Genetic diversity analysis indicated that the variation among populations (60.08%) was greater than that within populations (39.92%). Fixation index values, principal components analysis, structure, and phylogeny analyses showed that the population in Gyodongdo, Ganghwa Island was highly different. CONCLUSION: These results provide important insights for better understand the population history and genetic structure of P. amphibia.

The complete chloroplast genomes and phylogenetic analysis of Exbucklandia longipetala and Exbucklandia populnea (Hamamelidaceae).

Exbucklandia longipetala and Exbucklandia populnea are two evergreen trees of the genus Exbucklandia in the family Hamamelidaceae. In this study, the complete chloroplast genomes of E. longipetala and E. populnea were sequenced, assembled, and annotated. The total lengths of the chloroplast genomes were 160,723 bp and 160,744 bp, respectively, and both had a GC content of 38.1%. The complete chloroplast genomes of these two species had typical quadripartite structures: LSC region (88,972 bp and 88,989 bp), SSC region (18,907 bp and 18,911 bp) and a pair of inverted repeats both of 26,422 bp. Both species contained 114 unique genes, including 80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis indicated that E. longipetala and E. populnea are sister species to each other. Our results provide useful genetic resources for further studies on the origin and evolution of Hamamelidaceae.

Phylogenetics and species delimitation of the recluse spider, Loxosceles rufescens (Araneae: Sicariidae) populations invading Bangkok, Thailand.

The Mediterranean recluse spider, Loxosceles rufescens, has been discovered for the first time inhabiting human dwellings in Bangkok, Thailand. Expeditions across 39 localities revealed five establishments with L. rufescens populations. The highest density was recorded in a storage house on Yaowarat Road, located in the heart of Bangkok's Chinatown, where 315 individuals were found, including adults, juveniles, and spiderlings. This medically significant spider's presence in such a densely populated urban area raises concerns about potential envenomation risks. Thirteen specimens of L. rufescens were extracted for DNA and sequenced for molecular phylogenetic analyses. COI and ITS2 markers were used to investigate relationships within L. rufescens and across available Loxosceles species sequences. Results indicate COI is superior for resolving species-level genetic clusters compared to ITS2. Surprisingly, L. rufescens individuals from the same house were found in significantly distant COI lineages, suggesting mtDNA may not be suitable for studying intra-specific phylogeography in this case. Species delimitation methods ABGD and ASAP demonstrated promising results for both COI and ITS2, while bPTP and GMYC tended to overestimate species numbers. ITS2 exhibited high sequence similarity in L. rufescens, suggesting potential utility as a barcoding marker for identification of this globally distributed species. Genetic distance analyses revealed a potential barcoding gap (K2P) of 8-9 % for COI and <2 % for ITS2 in Loxosceles. This study contributes valuable sequence data for the medically important genus Loxosceles and highlights the need for integrative approaches in understanding its evolution and spread. The findings have important implications for pest management strategies and public health in urban environments.

Whole Mitochondrial Genome Sequencing and Phylogenetic Tree Construction for Procypris mera (Lin 1933).

Procypris mera (Lin, 1933), also known as the Chinese ink carp, currently has a second-class protection status in China. Understanding the structure and characteristics of mitochondrial genes provides essential information for resource conservation and phylogenetic studies of P. mera. Here, we sequenced the mitochondrial genomes of three P. mera (WYL1-3) from three sites and performed phylogenetic analysis. The generated three genomes were 16,587 bp in length, comprising 13 protein-coding genes (PCGs), 22 tRNAs, two rRNAs, and two non-coding regions (control region (CR), D-loop, and light-stranded replication start OL), with a preference for codons ending in A or C. The mitochondrial genomes of WYL2 and WYL3 were identical, differing from that of WYL1 by only five single-nucleotide polymorphisms (SNPs). All mitochondrial PCGs had Ka/Ks ratios of less than one, suggesting purifying selection. Phylogenetic tree analysis based on amino acid sequences suggested that the genus Puntioplites is sister to all other genera of the subfamily Cyprinidae of China; the genus Procypris forms a monophyletic group; and the genera Carassioides, Carassius, and Cyprinus form a monophyletic group. This study contributes to our understanding of the phylogenetic relationships in subfamily Cyprininae in China and lays the foundation for resource conservation and management of P. mera.

New insights on the phylogeny, evolutionary history, and ecological adaptation mechanism in cycle-cup oaks based on chloroplast genomes.

Cycle-cup oaks (Quercus section Cyclobalanopsis) are one of the principal components of forests in the tropical and subtropical climates of East and Southeast Asia. They have experienced relatively recent increases in the diversification rate, driven by changing climates and the Himalayan orogeny. However, the evolutionary history and adaptive mechanisms at the chloroplast genome level in cycle-cup oaks remain largely unknown. Therefore, we studied this problem by conducting chloroplast genomics on 50 of the ca. 90 species. Comparative genomics and other analyses showed that Quercus section Cyclobalanopsis had a highly conserved chloroplast genome structure. Highly divergent regions, such as the ndhF and ycf1 gene regions and the petN-psbM and rpoB-trnC-GCA intergenic spacer regions, provided potential molecular markers for subsequent analysis. The chloroplast phylogenomic tree indicated that Quercus section Cyclobalanopsis was not monophyletic, which mixed with the other two sections of subgenus Cerris. The reconstruction of ancestral aera inferred that Palaeotropics was the most likely ancestral range of Quercus section Cyclobalanopsis, and then dispersed to Sino-Japan and Sino-Himalaya. Positive selection analysis showed that the photosystem genes had the lowest ω values among the seven functional gene groups. And nine protein-coding genes containing sites for positive selection: ndhA, ndhD, ndhF, ndhH, rbcL, rpl32, accD, ycf1, and ycf2. This series of analyses together revealed the phylogeny, evolutionary history, and ecological adaptation mechanism of the chloroplast genome of Quercus section Cyclobalanopsis in the long river of earth history. These chloroplast genome data provide valuable information for deep insights into phylogenetic relationships and intraspecific diversity in Quercus.

Differences between phytophagous and predatory species in Pentatomidae based on the mitochondrial genome.

Pentatomidae includes many species of significant economic value as plant pests and biological control agents. The feeding habits of Pentatomidae are closely related to their energy metabolism and ecological adaptations. In this study, we sequenced the mitochondrial genomes of 12 Asopinae species using the next-generation sequencing to explore the effect of dietary changes on mitochondrial genome evolution. Notably, all sequences were double-stranded circular DNA molecules containing 37 genes and one control region. We then compared and analyzed the mitochondrial genome characteristics of phytophagous and predatory bugs. Notably, no significant difference was observed in the length of the mitochondrial genomes between the predatory and phytophagous bugs. However, the AT content was higher in the mitochondrial genomes of phytophagous bugs than that of predatory bugs. Moreover, phytophagous bugs prefer codon usage patterns ending in A/T compared with predatory bugs. The evolution rate of predatory bugs was lower than that of phytophagous bugs. The phylogenetic relationships across phytophagous bugs' lineages were largely consistent at depth nodes based on different datasets and tree-reconstructing methods, and strongly supported the monophyly of predatory bugs. Additionally, the estimated divergence times indicated that Pentatomidae explosively radiated in the Early Cretaceous. Subsequently, the subfamily Asopinae and the genus Menida diverged in the Late Cretaceous. Our research results provide data supporting for the evolutionary patterns and classification of Pentatomidae.

Characteristics and phylogenetic analysis of the complete chloroplast genome of Vernonia volkameriifolia DC. 1836 (Asteraceae).

Vernonia volkameriifolia DC. 1836, is a woody shrub of the subfamily Vernonioideae within the family Asteraceae. The complete chloroplast genome of V. volkameriifolia spans 152,934 bp, comprising four subregions: a large single-copy region (84,035 bp), a small single-copy region (18,543 bp), and a pair of inverted repeats (25,178 bp). Within the chloroplast genome of V. volkameriifolia, 114 unique genes were identified, including 80 unique protein-encoding genes, four ribosomal RNA (rRNA) genes, and 30 transfer RNA (tRNA) genes. Phylogenetic analysis based on the complete chloroplast genome of six related taxa in the Vernonieae tribe indicates that V. volkameriifolia show closer relationships with Vernonia parishii and Strobocalyx arborea. The first chloroplast genome of V. volkameriifolia was reported in this work, contributing to the enrichment of genomic data for the genus Vernonia.

The Phylogenetic Relationships of Major Lizard Families Using Mitochondrial Genomes and Selection Pressure Analyses in Anguimorpha.

Anguimorpha, within the order Squamata, represents a group with distinct morphological and behavioral characteristics in different ecological niches among lizards. Within Anguimorpha, there is a group characterized by limb loss, occupying lower ecological niches, concentrated within the subfamily Anguinae. Lizards with limbs and those without exhibit distinct locomotor abilities when adapting to their habitats, which in turn necessitate varying degrees of energy expenditure. Mitochondria, known as the metabolic powerhouses of cells, play a crucial role in providing approximately 95% of an organism's energy. Functionally, mitogenomes (mitochondrial genomes) can serve as a valuable tool for investigating potential adaptive evolutionary selection behind limb loss in reptiles. Due to the variation of mitogenome structures among each species, as well as its simple genetic structure, maternal inheritance, and high evolutionary rate, the mitogenome is increasingly utilized to reconstruct phylogenetic relationships of squamate animals. In this study, we sequenced the mitogenomes of two species within Anguimorpha as well as the mitogenomes of two species in Gekkota and four species in Scincoidea. We compared these data with the mitogenome content and evolutionary history of related species. Within Anguimorpha, between the mitogenomes of limbless and limbed lizards, a branch-site model analysis supported the presence of 10 positively selected sites: Cytb protein (at sites 183 and 187), ND2 protein (at sites 90, 155, and 198), ND3 protein (at site 21), ND5 protein (at sites 12 and 267), and ND6 protein (at sites 72 and 119). These findings suggested that positive selection of mitogenome in limbless lizards may be associated with the energy requirements for their locomotion. Additionally, we acquired data from 205 mitogenomes from the NCBI database. Bayesian inference (BI) and Maximum Likelihood (ML) trees were constructed using the 13 mitochondrial protein-coding genes (PCGs) and two rRNAs (12S rRNA and 16S rRNA) from 213 mitogenomes. Our phylogenetic tree and the divergence time estimates for Squamata based on mitogenome data are consistent with results from previous studies. Gekkota was placed at the root of Squamata in both BI and ML trees. However, within the Toxicofera clade, due to long-branch attraction, Anguimorpha and (Pleurodonta + (Serpentes + Acrodonta)) were closely related groupings, which might indicate errors and also demonstrate that mitogenome-based phylogenetic trees may not effectively resolve long-branch attraction issues. Additionally, we reviewed the origin and diversification of Squamata throughout the Mesozoic era, suggesting that Squamata originated in the Late Triassic (206.05 Mya), with the diversification of various superfamilies occurring during the Cretaceous period. Future improvements in constructing squamate phylogenetic relationships using mitogenomes will rely on identifying snake and acrodont species with slower evolutionary rates, ensuring comprehensive taxonomic coverage of squamate diversity, and increasing the number of genes analyzed.

Complete Plastid Genome Sequences of Four Salsoleae s.l. Species: Comparative and Phylogenetic Analyses.

The taxonomic classification of the genera Salsola L., Pyankovia Akhani and Roalson, and Xylosalsola Tzvelev within Chenopodiaceae Vent. (Amaranthaceae s.l.) remains controversial, with the precise number of species within these genera still unresolved. This study presents a comparative analysis of the complete plastid genomes of S. foliosa, S. tragus, P. affinis, and X. richteri species collected in Kazakhstan. The assembled plastid genomes varied in length, ranging from 151,177 bp to 152,969 bp for X. richteri and S. tragus. These genomes contained 133 genes, of which 114 were unique, including 80 protein-coding, 30 tRNA, and 4 rRNA genes. Thirteen regions, including ndhC-ndhD, rps16-psbK, petD, rpoC2, ndhA, petB, clpP, atpF, ycf3, accD, ndhF-ndhG, matK, and rpl20-rpl22, exhibited relatively high levels of nucleotide variation. A total of 987 SSRs were detected across the four analyzed plastid genomes, primarily located in the intergenic spacer regions. Additionally, 254 repeats were identified, including 92 tandem repeats, 88 forward repeats, 100 palindromic repeats, and only one reverse repeat. A phylogenetic analysis revealed clear clustering into four clusters corresponding to the Salsoleae and Caroxyloneae tribe clades. These nucleotide sequences obtained in this study represent a valuable resource for future phylogenetic analyses within the Salsoleae s.l. tribe.

The complete chloroplast genome sequence of Hypecoum erectum L. (Papaveraceae).

Hypecoum erectum L., a widespread species in northern Eurasia, is a valuable medicinal plant, but its chloroplast genome has not previously been reported. We determined its complete chloroplast genome using a high-throughput sequencing technique. Its total length was 169,241 bp, consisting of a large single-copy region of 93,301 bp and a small single-copy region of 17,316 bp, separated by a pair of inverted repeat regions of 29,312 bp. A total of 140 genes were annotated, including 91 protein coding genes, 41 tRNA genes, and eight rRNA genes. The phylogenetic analysis shows that H. erectum and H. zhukanum of the subfamily Hypecoideae are monophyletic with the highest support.

Plastome evolution of Engelhardia facilitates phylogeny of Juglandaceae.

BACKGROUND: Engelhardia (Juglandaceae) is a genus of significant ecological and economic importance, prevalent in the tropics and subtropics of East Asia. Although previous efforts based on multiple molecular markers providing profound insights into species delimitation and phylogeography of Engelhardia, the maternal genome evolution and phylogeny of Engelhardia in Juglandaceae still need to be comprehensively evaluated. In this study, we sequenced plastomes from 14 samples of eight Engelhardia species and the outgroup Rhoiptelea chiliantha, and incorporated published data from 36 Juglandaceae and six outgroup species to test phylogenetic resolution. Moreover, comparative analyses of the plastomes were conducted to investigate the plastomes evolution of Engelhardia and the whole Juglandaceae family. RESULTS: The 13 Engelhardia plastomes were highly similar in genome size, gene content, and order. They exhibited a typical quadripartite structure, with lengths from 161,069 bp to 162,336 bp. Three mutation hotspot regions (TrnK-rps16, ndhF-rpl32, and ycf1) could be used as effective molecular markers for further phylogenetic analyses and species identification. Insertion and deletion (InDels) may be an important driving factor for the evolution of plastomes in Juglandoideae and Engelhardioideae. A total of ten codons were identified as the optimal codons in Juglandaceae. The mutation pressure mostly contributed to shaping codon usage. Seventy-eight protein-coding genes in Juglandaceae experienced relaxed purifying selection, only rpl22 and psaI genes showed positive selection (Ka/Ks > 1). Phylogenetic results fully supported Engelhardia as a monophyletic group including two sects and the division of Juglandaceae into three subfamilies. The Engelhardia originated in the Late Cretaceous and diversified in the Late Eocene, and Juglandaceae originated in the Early Cretaceous and differentiated in Middle Cretaceous. The phylogeny and divergence times didn't support rapid radiation occurred in the evolution history of Engelhardia. CONCLUSION: Our study fully supported the taxonomic treatment of at the section for Engelhardia species and three subfamilies for Juglandaceae and confirmed the power of phylogenetic resolution using plastome sequences. Moreover, our results also laid the foundation for further studying the course, tempo and mode of plastome evolution of Engelhardia and the whole Juglandaceae family.

Comparative Analysis of Plastome Sequences of Seven Tulipa L. (Liliaceae Juss.) Species from Section Kolpakowskianae Raamsd. Ex Zonn and Veldk.

Tulipa L. is a genus of significant economic, environmental, and cultural importance in several parts of the world. The exact number of species in the genus remains uncertain due to inherent taxonomic challenges. We utilized next-generation sequencing technology to sequence and assemble the plastid genomes of seven Tulipa species collected in Kazakhstan and conducted a comparative analysis. The total number of annotated genes was 136 in all seven studied Tulipa species, 114 of which were unique, including 80 protein-coding, 30 tRNA, and 4 rRNA genes. Nine regions (petD, ndhH, ycf2-ycf3, ndhA, rpl16, clpP, ndhD-ndhF, rpoC2, and ycf1) demonstrated significant nucleotide variability, suggesting their potential as molecular markers. A total of 1388 SSRs were identified in the seven Tulipa plastomes, with mononucleotide repeats being the most abundant (60.09%), followed by dinucleotide (34.44%), tetranucleotide (3.90%), trinucleotide (1.08%), pentanucleotide (0.22%), and hexanucleotide (0.29%). The Ka/Ks values of the protein-coding genes ranged from 0 to 3.9286, with the majority showing values <1. Phylogenetic analysis based on a complete plastid genome and protein-coding gene sequences divided the species into three major clades corresponding to their subgenera. The results obtained in this study may contribute to understanding the phylogenetic relationships and molecular taxonomy of Tulipa species.

A taxonomic backbone for the Plumbaginaceae (Caryophyllales).

A taxonomic backbone of the Plumbaginaceae is presented and the current state of knowledge on phylogenetic relationships and taxon limits is reviewed as a basis for the accepted taxon concepts. In total, 4,476 scientific names and designations are treated of which 30 are not in the family Plumbaginaceae. The Plumbaginaceae are subdivided in three tribes with 26 genera and 1,179 accepted species. Two subgenera, 17 sections, two subsections and 187 infraspecific taxa are accepted. At the species and infraspecific level 2,782 synonyms were assigned to accepted taxa, whereas 194 names were excluded from the core checklist (i.e., unplaced taxa, infrageneric subdivisions with still uncertain application, names of verified uncertain application, invalid horticultural names, excluded names from other families, other excluded designations, and unresolved names). The EDIT Platform for Cybertaxonomy was utilized as the tool to compile and manage the names and further taxonomic data under explicit taxon concepts. Secundum references are given in case taxon concepts were taken from the literature, whereas this study serves as reference for newly circumscribed taxa. The family's division into the tribes Aegialitideae, Limonieae, and Plumbagineae departs from earlier two-subfamily classifications, prompted by recent phylogenetic findings that challenge the subfamilial affinity of Aegialitis. The genus Acantholimon was extended to include Gladiolimon, as currently available phylogenetic and morphological data support this merger. In Limonium, all accepted species could be assigned to sections and subsections or the "Mediterranean lineage", respectively, making use of the phylogenetic distribution of their morphological characters and states. A new combination and/or status is proposed for Dyerophytumsocotranum, Limoniumthymoides, Limonium×fraternum, Limonium×rossmaessleri, and Limoniumsect.Jovibarba. Special attention is given to nomenclatural issues, particularly for Staticenomenambiguum to resolve the names under accepted names. The use of artificial groupings like "aggregates", "complexes" and "species groups" in alpha-taxonomic treatments is discussed. The taxonomic backbone will receive continued updates and through the Caryophyllales Taxonomic Expert Network, it contributes the treatment of the Plumbaginaceae for the World Flora Online.

Identification and Functional Implications of the E5 Oncogene Polymorphisms of Human Papillomavirus Type 16.

The persistence of the human papillomavirus type 16 (HPV16) infection on the cervical epithelium contributes to the progression of cervical cancer. Studies have demonstrated that HPV16 genetic variants may be associated with different risks of developing cervical cancer. However, the E5 oncoprotein of HPV16, which is related to several cellular mechanisms in the initial phases of the infection and thus contributes to carcinogenesis, is still little studied. Here we investigate the HPV16 E5 oncogene variants to assess the effects of different mutations on the biological function of the E5 protein. We detected and analyzed the HPV16 E5 oncogene polymorphisms and their phylogenetic relationships. After that, we proposed a tertiary structure analysis of the protein variants, preferential codon usage, and functional activity of the HPV16 E5 protein. Intra-type variants were grouped in the lineages A and D using in silico analysis. The mutations in E5 were located in the T-cell epitopes region. We therefore analyzed the interference of the HPV16 E5 protein in the NF-kB pathway. Our results showed that the variants HPV16E5_49PE and HPV16E5_85PE did not increase the potential of the pathway activation capacity. This study provides additional knowledge about the mechanisms of dispersion of the HPV16 E5 variants, providing evidence that these variants may be relevant to the modulation of the NF-κB signaling pathway.

Scale Characteristics of Six Fish Species of the Genus Cyprinion (Teleostei: Cypriniformes): A Microscopic Analysis.

This study investigated the morphological characteristics of scales in six Cyprinion species, using light and scanning electron microscopy focusing on key features such as scale type, key scales, lateral line scales, radius/radii, rostral margin, focus, circuli, lepidonts, tubercles, and scale indices. The research analyzed the scales using ultramicroscopy and light microscopy imaging, categorizing them based on size classes and body regions. The morphological variations in scale characteristics were examined across different species, regions, and size classes. Notable findings included the tetra-sectioned form of scales, representing a unique characteristic of the Cyprinion genus. Morphological changes in scale features were observed with fish growth, particularly in the overall shape, focus shape, and size. Quantitative analysis revealed variations in average relative scale length and width among different species, regions, and size classes. The study utilized canonical discriminant analysis for multivariate assessment, classifying the species into distinct groups based on morphometric indices. The findings contribute to the understanding of scale morphology in Cyprinion species and exploring morphological variation between the examined species.

Genomics and phylogenetic relationships of microsporidia and their relatives.

Microsporidia are intracellular parasites that all possess a unique infection apparatus involving a polar tube. Upon contact with a host cell, this tube forms the conduit through which the parasite enters the host. Infecting mostly animals, microsporidian species can be transmitted vertically or horizontally, and exert various effects on their hosts: infections range from being relatively benign to lethal. Microsporidian genomes possess highly divergent sequences and are often substantially reduced in size. Their divergent sequences and unique morphology created early challenges to our understanding of their phylogenetic position within the tree of eukaryotes. Over the last couple of decades, advances in both sequencing technology and phylogenetic methodology supported a clear relationship between microsporidia and fungi. However, the specifics of this relationship were muddied by the lack of known microsporidian relatives. With increased taxon discovery and the morphological and molecular characterization of microsporidia-like taxa, rozellids and aphelids, a better resolved picture is emerging. Here we review the history of microsporidian taxonomy and current status of genomics of microsporidia and their nearest relatives, with an aim to understand their morphological and metabolic differences, along with their evolutionary relationships.

Genetic diversity and haplotype distribution patterns analysis of cytb and RAG2 sequences in Rana hanluica from southern China.

Rana hanluica: an endemic amphibian of China, is found in the hills and mountains south of the Yangtze River. In this comprehensive study, we collected 162 samples from 14 different localities to delve into the genetic diversity of Rana hanluica using mitochondrial Cytb and nuclear RAG2 as genetic markers. Our findings reveal that the Nanling Mountains, specifically regions like Jiuyi Shan, Jinggang Shan, Mang Shan, and Qiyun Shan, are genetic hotspots harboring remarkable diversity. The research results also indicate that there is gene flow among the various populations of the species, and no distinct population structure has formed, which may be due to migration. Moreover, populations in some regions, as well as the overall population, show signs of a possible genetic bottleneck, which we speculate may have been caused by climate change. However, given the exploratory nature of our study, further investigations are warranted to confirm these observations. Through phylogenetic analyses, we uncovered indications that R. hanluica might have originated within the Nanling region, dispersing along the east-west mountain ranges, with a significant contribution originating from Jiuyi Shan. The genetic distributions uncovered through our research reflect historical migratory patterns, evident in the distinct haplotypes of the RAG2 gene between the western and eastern parts of the studied area. Moreover, Heng Shan and Yangming Shan exhibited unique genetic signatures, possibly influenced by geographic isolation, which has shaped their distinct genotypes. The insights gained from this study hold profound implications for conservation efforts. By identifying regions rich in genetic diversity and crucial gene flow corridors, we can develop more effective conservation strategies. Preserving these genetically diverse areas, especially within the Nanling Mountains, is vital for maintaining the evolutionary potential of R. hanluica. In conclusion, our research has laid a solid foundation for understanding the genetic landscape of R. hanluica, shedding light on its origins, population structures, and evolutionary trajectories. This knowledge will undoubtedly guide future research endeavors and inform conservation strategies for this endemic amphibian.

Molecular evidence provides new insights into the evolutionary origin of an ancient traditional Chinese medicine, the domesticated "Baizhi".

Introduction: "Baizhi" is a famous herbal medicine in China, and it includes four landraces named as 'Hangbaizhi', 'Chuanbaizhi', 'Qibaizhi', and 'Yubaizhi'. Long-term artificial selection had caused serious degradation of these germplasms. Determining the wild progenitor of the landraces would be benefit for their breed improvements. Previous studies have suggested Angelica dahurica var. dahurica, A. dahurica var. formosana, or A. porphyrocaulis as potential candidates, but the conclusion remains uncertain, and their phylogenetic relationships are still in controversy. Methods: In this study, the genetic variation and phylogenetic analyses of these species and four landraces were conducted on the basis of both the nrITS and plastome datasets. Results: Genetic variation analysis showed that all 8 population of four landraces shared only one ITS haplotype, meanwhile extremely low variation occurred within 6 population at plastid genome level. Both datasets supported the four landraces might be originated from a single wild germplasm. Phylogenetic analyses with both datasets revealed largely consistent topology using Bayesian inference and Maximum likelihood methods. Samples of the four landraces and all wild A. dahurica var. dahurica formed a highly supported monophyletic clade, and then sister to the monophyly clade comprised by samples of A. porphyrocaulis, while four landraces were clustered into one clade, which further clustered with a mixed branches of A. porphyrocaulis and A. dahurica var. dahurica to form sister branches for plastid genomes. Furthermore, the monophyletic A. dahurica var. formosana was far distant from the A. dahurica var. dahurica-"Baizhi" clade in Angelica phylogeny. Such inferences was also supported by the evolutionary patterns of nrITS haplotype network and K2P genetic distances. The outcomes indicated A. dahurica var. dahurica is most likely the original plant of "Baizhi". Discussion: Considering of phylogenetic inference and evolutionary history, the species-level status of A. dahurica var. formosana should be accepted, and the taxonomic level and phylgenetic position of A. porphyrocaulis should be further confirmed. This study preliminarily determined the wild progenitor of "Baizhi" and clarified the phylogenetic relationships among A. dahurica var. dahurica, A. dahurica var. formosana and A. porphyrocaulis, which will provide scientific guidance for wild resources protections and improvement of "Baizhi".

Sequence comparison of the mitochondrial genomes of Plesionika species (Caridea: Pandalidae), gene rearrangement and phylogenetic relationships of Caridea.

Background: Despite the Caridean shrimps' vast species richness and ecological diversity, controversies persist in their molecular classification. Within Caridea, the Pandalidae family exemplifies significant taxonomic diversity. As of June 25, 2023, GenBank hosts only nine complete mitochondrial genomes (mitogenomes) for this family. The Plesionika genus within Pandalidae is recognized as polyphyletic. To improve our understanding of the mitogenome evolution and phylogenetic relationships of Caridea, this study introduces three novel mitogenome sequences from the Plesionika genus: P.  ortmanni, P. izumiae and P. lophotes. Methods: The complete mitochondrial genomes of three Plesionika species were sequenced utilizing Illumina's next-generation sequencing (NGS) technology. After assembling and annotating the mitogenomes, we conducted structural analyses to examine circular maps, sequence structure characteristics, base composition, amino acid content, and synonymous codon usage frequency. Additionally, phylogenetic analysis was performed by integrating existing mitogenome sequences of true shrimp available in GenBank. Results: The complete mitogenomes of the three Plesionika species encompass 37 canonical genes, comprising 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and one control region (CR). The lengths of these mitogenomes are as follows: 15,908 bp for P. ortmanni, 16,074 bp for P. izumiae and 15,933 bp for P. lophotes. Our analyses extended to their genomic features and structural functions, detailing base composition, gene arrangement, and codon usage. Additionally, we performed selection pressure analysis on the PCGs of all Pandalidae species available in Genbank, indicating evolutionary purification selection acted on the PCGs across Pandalidae species. Compared with the ancestral Caridea, translocation of two tRNA genes, i.e., trnP or trnT, were found in the two newly sequenced Plesionika species-P. izumiae and P. lophotes. We constructed a phylogenetic tree of Caridea using the sequences of 13 PCGs in mitogenomes. The results revealed that family Pandalidae exhibited robust monophyly, while genus Plesionika appeared to be a polyphyletic group. Conclusions: Gene rearrangements within the Pandalidae family were observed for the first time. Furthermore, a significant correlation was discovered between phylogenetics of the Caridea clade and arrangement of mitochondrial genes. Our findings offer a detailed exploration of Plesionika mitogenomes, laying a crucial groundwork for subsequent investigations into genetic diversity, phylogenetic evolution, and selective breeding within this genus.