Sex-dependent metabolic remodeling of kidneys revealed by arteriovenous metabolomics.

Sex is a fundamental biological variable important in biomedical research, drug development, clinical trials, and prevention approaches. Among many organs, kidneys are known to exhibit remarkable structural, histological, and pathological differences between sexes. However, whether and how kidneys display distinct metabolic activities between sexes is poorly understood. By developing kidney-specific arteriovenous (AV) metabolomics combined with transcriptomics, we report striking sex differences in both basal metabolic activities and adaptive metabolic remodeling of kidneys after a fat-enriched ketogenic diet (KD), a regimen known to mitigate kidney diseases and improve immunotherapy for renal cancer. At the basal state, female kidneys show highly accumulated aldosterone and various acylcarnitines. In response to the KD, aldosterone levels remain high selectively in females but the sex difference in acylcarnitines disappears. AV data revealed that, under KD, female kidneys avidly take up circulating fatty acids and release 3-hydroxybutyrate (3-HB) whereas male kidneys barely absorb fatty acids but consistently take up 3-HB. Although both male and female kidneys take up gluconeogenic substrates such as glycerol, glutamine and lactate, only female kidneys exhibit net glucose release. Kidney transcriptomics data incompletely predict these sex differences, suggesting post-transcriptional/translational regulation mechanisms. This study provides foundational insights into the sex-dependent and diet-elicited metabolic flexibility of the kidneys in vivo, serving as a unique resource for understanding variable disease prevalence and drug responses between male and female kidneys.

Comparative phylogenomic study of East Asian endemic genus, Corchoropsis Siebold & Zucc. (Malvaceae s.l.), based on complete plastome sequences.

BACKGROUND: Endemic plants are key to understanding the evolutionary history and enhancing biodiversity within their unique regions, while also offering significant economic potential. The East Asian endemic genus Corchoropsis Siebold & Zucc., classified within the subfamily Dombeyoideae of Malvaceae s.l., comprises three species. RESULTS: This study characterizes the complete plastid genomes (plastomes) of C. crenata var. crenata Siebold & Zucc. and C. crenata var. hupehensis Pamp., which range from 160,093 to 160,724 bp. These genomes contain 78 plastid protein-coding genes, 30 tRNA, and four rRNA, except for one pseudogene, infA. A total of 316 molecular diagnostic characters (MDCs) specific to Corchoropsis were identified. In addition, 91 to 92 simple sequence repeats (SSRs) in C. crenata var. crenata and 75 in C. crenata var. hupehensis were found. Moreover, 49 long repeats were identified in both the Chinese C. crenata var. crenata and C. crenata var. hupehensis, while 52 were found in the South Korean C. crenata var. crenata. Our phylogenetic analyses, based on 78 plastid protein-coding genes, reveal nine subfamilies within the Malvaceae s.l. with high support values and confirm Corchoropsis as a member of Dombeyoideae. Molecular dating suggests that Corchoropsis originated in the Oligocene, and diverged during the Miocene, influenced by the climate shift at the Eocene-Oligocene boundary. CONCLUSIONS: The research explores the evolutionary relationships between nine subfamilies within the Malvaceae s.l. family, specifically identifying the position of the Corchoropsis in the Dombeyoideae. Utilizing plastome sequences and fossil data, the study establishes that Corchoropsis first appeared during the Eocene and experienced further evolutionary divergence during the Miocene, paralleling the evolutionary patterns observed in other East Asian endemic species.

Exploring the therapeutic potential of Potentilla fragarioides var. major (Rosaceae) extract in Alzheimer's disease using in vitro and in vivo models: A multi-faceted approach.

Alzheimer's disease (AD) is the most common cause of dementia and is caused by various factors including amyloid-beta (Aß) aggregation. We investigated the pharmacological effects of the ethanol extract of Potentilla fragarioides var. major (Rosaceae) (EEPF) on AD-related pathogenesis, which remain elusive. We observed the effects of EEPF on Aß disaggregation and free-radical scavenging activities for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) using in vitro assays, evaluated the effects of EEPF on memory loss in two animal models, and examined the molecular regulatory mechanisms of EEPF using an antibody-protein microarray in EEPF-treated neuronal cell lines. EEPF inhibited Aß aggregation in a concentration-dependent manner and enhanced free-radical scavenging activities for ABTS and DPPH. EEPF significantly inhibited memory impairment in the passive avoidance task, Y-maze test, and Morris water maze test in scopolamine-induced short-term memory loss mice and Aß-injected AD-like mice. Nissl staining and immunohistochemistry for NeuN and Iba-1 confirmed the neuroprotective and anti-inflammatory effects of EEPF in both animal models. In H2O2-treated HT22 hippocampal cells, EEPF significantly prevented cell damage, enhanced CaMK2, and reduced ferric reductase. In lipopolysaccharide (LPS)-stimulated BV-2 microglia, EEPF significantly inhibited LPS-induced production of inflammatory factors, such as nitric oxide, prostaglandin E2, tumor necrosis factor-α, and interleukin-6, and decreased the phosphorylation of Smad3 and cyclin D3. High-performance liquid chromatography confirmed that EEPF has five major components: neochlorogenic acid, chlorogenic acid, polydatin, isochlorogenic acid A, and buddleoside, with amounts ranging across 1.91-9.41 mg/g. EEPF may be a promising drug for treatment of AD and AD-related brain disorders.

Round Robin Study for Evaluation an in vitro skin irritation test for medical device extracts using KeraSkinTM in Korea.

With the growing importance of alternative test methods that implement the 3Rs principles (Reduction, Refinement and Replacement) and the global importance of biological safety assessment data for medical devices is increasing. We have developed and optimized the 'KeraSkin™ Skin Irritation Test (KeraSkin™ SIT) for medical device' for regulatory application in biological evaluation according to ISO 10993-23. We conducted a round robin study to optimize and evaluate the performance of KeraSkin™ SIT for medical devices using KeraSkin™ Reconstructed Human Epidermis (RhE), which is developed and manufactured in Korea. This round robin study was performed to assess the transferability, reproducibility (within and between laboratories) and predictive capacity in 1 lead laboratory and 3 participating laboratories based on OECD Guidance Document 34. The predictive capacity, the results showed 83.3 % of sensitivity, 100 % of specificity and 91.6 % of accuracy. In conclusion, the results demonstrate that 'KeraSkin™ SIT for medical device' provides a robust test method for detecting irritant activity of medical device extracts and can be utilized for identifying low levels of potent irritants in medical device extracts. Therefore, it fulfills the requirements to be included as a 'me-too' test method to EpiDerm™ and SkinEthic™ skin irritation test in ISO 10993-23.

Circulating biomarkers of kidney angiomyolipoma and cysts in tuberous sclerosis complex patients.

Patients with tuberous sclerosis complex (TSC) develop multi-organ disease manifestations, with kidney angiomyolipomas (AML) and cysts being one of the most common and deadly. Early and regular AML/cyst detection and monitoring are vital to lower TSC patient morbidity and mortality. However, the current standard of care involves imaging-based methods that are not designed for rapid screening, posing challenges for early detection. To identify potential diagnostic screening biomarkers of AML/cysts, we performed global untargeted metabolomics in blood samples from 283 kidney AML/cyst-positive or -negative TSC patients using mass spectrometry. We identified 7 highly sensitive chemical features, including octanoic acid, that predict kidney AML/cysts in TSC patients. Patients with elevated octanoic acid have lower levels of very long-chain fatty acids (VLCFAs), suggesting that dysregulated peroxisome activity leads to overproduction of octanoic acid via VLCFA oxidation. These data highlight AML/cysts blood biomarkers for TSC patients and offers valuable metabolic insights into the disease.

A retrospective analysis of conception per embryo transfer in dairy cattle in South Korea.

The bovine embryo production industry has seen significant growth over the past two decades, particularly in the production of in vitro produced embryos. This growth, driven by advancements in cryopreservation, in vitro culture mediums, ovum pick-up (OPU) procedures, ultrasonography devices, and embryo transfer (ET) has been notable. Particularly, ET is crucial for disseminating high genetic merit and amplifying foreign breeds by importing frozen embryos. This retrospective study aimed to assess factors affecting conception per embryo transfer (CPET) in Holstein-Friesian cattle in South Korea from October 2008 to July 2022. We evaluated type of embryo breed, type of embryo production (fresh and frozen; in vitro and in vivo production), recipient conditions including estrus type, corpus luteum quality, parity (nulliparous heifers, primiparous, and multiparous cows), and the daily mean temperature-humidity index (THI) as an index for heat stress. Type of embryo breed and estrus had no significant impact on CPET. However, we observed higher CPET in recipients with good quality corpus luteum, nulliparous heifers, and surrogates receiving fresh in vitro and frozen in vivo embryos. Importantly, CPET was not adversely affected by mild heat stress conditions (up to daily mean THI 76), indicating that using frozen in vivo embryos produced by multiple ovulation embryo transfer and fresh in vitro embryos by OPU-ET can help alleviate the subfertility issues in dairy cattle caused by global warming in Korea.

The impact of sexual reproduction-induced vertical migration on the complexity of harmful algal blooms in Heterosigma akashiwo.

Vertical migration behaviour, which is integral to marine energy circulation, is a prevalent trait among marine organisms. However, the behaviour of phytoplankton, particularly beyond diel vertical migration (DVM), remain underexplored compared to groups like zooplankton. Through the lens of the harmful alga Heterosigma akashiwo, which exhibits active vertical migrations and unique fluctuating bloom dynamics, this study aimed to explore the ecological intricacies and diverse benefits of phytoplankton vertical migration behaviours. During the bloom period of H. akashiwo, we unexpectedly observed a dense concentration of cells at bottom layer during daytime. This phase coincided with the emergence of cells related to this species' sexual reproduction. Laboratory experiments further showed an elevated frequency of sexual reproduction in the cell populations that migrated to deeper depths compared to those at the surface. This finding implies a connection between dense bottom accumulation (BA) and the life cycle transitions of the species. This BA phase persisted for two days, after which the populations returned to their standard DVM behaviour, providing insight into the unique fluctuating bloom dynamics of H. akashiwo. Our study suggests that phytoplankton vertical migrations are not strictly dictated by DVM, revealing diverse vertical migration behaviours that may contribute to the complexity of harmful algal bloom patterns.

KoCVAM-led development of phototoxicity alternative test method using reconstructed human epidermis model (KeraSkin™).

Phototoxicity is an acute toxic reaction induced by topical skin exposure to photoreactive chemicals followed by exposure to environmental light and thus chemicals that absorb UV are recommended to be evaluated for phototoxic potential. There are currently three internationally harmonized alternative test methods for phototoxicity. One of them is the in vitro Phototoxicity: RhE Phototoxicity test method (OECD TG498). Korean center for the Validation of Alternative Methods (KoCVAM) developed an in vitro phototoxicity test method using a KeraSkin™ reconstructed human epidermis model (KeraSkin™ Phototoxicity Assay) as a 'me-too' test method of OECD TG498. For the development and optimization of KeraSkin™ Phototoxicity Assay, the following test chemicals were used: 6 proficiency chemicals in OECD TG498 (3 phototoxic and 3 non-phototoxic), 6 reference chemicals in OECD Performance Standard No. 356 (excluding the proficiency test chemicals, 3 phototoxic and 3 non-phototoxic) and 13 additional chemicals (7 phototoxic and 6 non-phototoxic). Based on the test results generated from the test chemicals above, the overall predictive capacity of KeraSkin™ Phototoxicity Assay was calculated. In particular, the assay exhibited 100 % accuracy, 100 % sensitivity, and 100 % specificity. Therefore, it fulfills the requirements to be included as a 'me-too' test method in OECD TG498.

Comprehensive understanding of the life history of harmful raphidophyte Heterosigma akashiwo: Integrating in situ and in vitro observations.

Heterosigma akashiwo (Raphidophyceae) is widely recognized as a species responsible for harmful algal blooms worldwide. The species has long been speculated to possess a more complex life history, attributed to the diverse morphological variations observed during cell cultivation. However, the understanding of its life history has remained insufficient due to limitations in observing transitions between life cycle stages in vitro and challenges associated with in situ investigations. In this study, a combination of in vitro (laboratory-based) and in situ (field-based) observations was employed to define the life cycle stages of H. akashiwo and elucidate the pathways of transition between these stages. Notably, novel homothallic sexual reproduction processes involving the fusion of hologametes and the subsequent formation of zygotes were observed for the first time in vitro. These zygotes were found to either divide into vegetative cells (Pathway I) or undergo enlargement, resulting in the formation of multiple cells with multiple nuclei (Pathway II). Furthermore, this study provides the first documentation of large cells and cell clusters in situ, including intermediate stages referred to as large cells with ongoing cytoplasmic division that serve as a bridge between these two cell types. The observed zygotes in vitro exhibited a large size (21.9-51.8 µm) and multinucleated characteristics, similar to the large cells (38.2-45.8 µm) and cell clusters observed in situ. This finding suggests that the large cells observed in situ were zygotes undergoing cell division to form cell clusters (Pathway III). Moreover, based on the striking similarities in cell morphology and nuclear size between the cells comprising the cell cluster (2.7-4.4 µm) and the cyst clusters of this species, along with the synchronized germination characteristics of cyst clusters, it is proposed that the cell cluster serves as a precursor to cysts. By integrating the in situ and in vitro observations, this study provides a comprehensive understanding of the previously poorly understood life history of H. akashiwo.

MAPK13 stabilization via m6A mRNA modification limits anticancer efficacy of rapamycin.

N6-adenosine methylation (m6A) is the most abundant mRNA modification that controls gene expression through diverse mechanisms. Accordingly, m6A-dependent regulation of oncogenes and tumor suppressors contributes to tumor development. However, the role of m6A-mediated gene regulation upon drug treatment or resistance is poorly understood. Here, we report that m6A modification of mitogen-activated protein kinase 13 (MAPK13) mRNA determines the sensitivity of cancer cells to the mechanistic target of rapamycin complex 1 (mTORC1)-targeting agent rapamycin. mTORC1 induces m6A modification of MAPK13 mRNA at its 3' untranslated region through the methyltransferase-like 3 (METTL3)-METTL14-Wilms' tumor 1-associating protein(WTAP) methyltransferase complex, facilitating its mRNA degradation via an m6A reader protein YTH domain family protein 2. Rapamycin blunts this process and stabilizes MAPK13. On the other hand, genetic or pharmacological inhibition of MAPK13 enhances rapamycin's anticancer effects, which suggests that MAPK13 confers a progrowth signal upon rapamycin treatment, thereby limiting rapamycin efficacy. Together, our data indicate that rapamycin-mediated MAPK13 mRNA stabilization underlies drug resistance, and it should be considered as a promising therapeutic target to sensitize cancer cells to rapamycin.

FAM120A couples SREBP-dependent transcription and splicing of lipogenesis enzymes downstream of mTORC1.

The mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth that stimulates macromolecule synthesis through transcription, RNA processing, and post-translational modification of metabolic enzymes. However, the mechanisms of how mTORC1 orchestrates multiple steps of gene expression programs remain unclear. Here, we identify family with sequence similarity 120A (FAM120A) as a transcription co-activator that couples transcription and splicing of de novo lipid synthesis enzymes downstream of mTORC1-serine/arginine-rich protein kinase 2 (SRPK2) signaling. The mTORC1-activated SRPK2 phosphorylates splicing factor serine/arginine-rich splicing factor 1 (SRSF1), enhancing its binding to FAM120A. FAM120A directly interacts with a lipogenic transcription factor SREBP1 at active promoters, thereby bridging the newly transcribed lipogenic genes from RNA polymerase II to the SRSF1 and U1-70K-containing RNA-splicing machinery. This mTORC1-regulated, multi-protein complex promotes efficient splicing and stability of lipogenic transcripts, resulting in fatty acid synthesis and cancer cell proliferation. These results elucidate FAM120A as a critical transcription co-factor that connects mTORC1-dependent gene regulation programs for anabolic cell growth.

A phylogenomic study of Iridaceae Juss. based on complete plastid genome sequences.

The plastid genome has proven to be an effective tool for examining deep correlations in plant phylogenetics, owing to its highly conserved structure, uniparental inheritance, and limited variation in evolutionary rates. Iridaceae, comprising more than 2,000 species, includes numerous economically significant taxa that are frequently utilized in food industries and medicines and for ornamental and horticulture purposes. Molecular studies on chloroplast DNA have confirmed the position of this family in the order Asparagales with non-asparagoids. The current subfamilial classification of Iridaceae recognizes seven subfamilies-Isophysioideae, Nivenioideae, Iridoideae, Crocoideae, Geosiridaceae, Aristeoideae, and Patersonioideae-which are supported by limited plastid DNA regions. To date, no comparative phylogenomic studies have been conducted on the family Iridaceae. We assembled and annotated (de novo) the plastid genomes of 24 taxa together with seven published species representing all the seven subfamilies of Iridaceae and performed comparative genomics using the Illumina MiSeq platform. The plastomes of the autotrophic Iridaceae represent 79 protein-coding, 30 tRNA, and four rRNA genes, with lengths ranging from 150,062 to 164,622 bp. The phylogenetic analysis of the plastome sequences based on maximum parsimony, maximum likelihood, and Bayesian inference analyses suggested that Watsonia and Gladiolus were closely related, supported by strong support values, which differed considerably from recent phylogenetic studies. In addition, we identified genomic events, such as sequence inversions, deletions, mutations, and pseudogenization, in some species. Furthermore, the largest nucleotide variability was found in the seven plastome regions, which can be used in future phylogenetic studies. Notably, three subfamilies-Crocoideae, Nivenioideae, and Aristeoideae-shared a common ycf2 gene locus deletion. Our study is a preliminary report of a comparative study of the complete plastid genomes of 7/7 subfamilies and 9/10 tribes, elucidating the structural characteristics and shedding light on plastome evolution and phylogenetic relationships within Iridaceae. Additionally, further research is required to update the relative position of Watsonia within the tribal classification of the subfamily Crocoideae.

Characterization of the complete plastid genome of Korean endemic, Ajuga spectabilis Nakai (Lamiaceae).

Ajuga spectabilis Nakai is a Korean endemic species in Lamiaceae. In spite of its importance, genomic studies are not performed on this species. Here, we report the complete plastid genome sequences of A. spectabilis, which will provide valuable information for its natural conservation and future studies for the plastid genome evolution. The plastid genome is 150,417 bp in length, containing a large single-copy region (LSC) of 82,140 bp and a small single-copy (SSC) region of 17,165 bp which are separated by a pair of inverted repeats (IR) of 25,556 bp. It encodes 113 genes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. The overall GC content is 38.3%, and those in the LSC, SSC, and IR regions are 36.4%, 32.2%, and 43.3%, respectively, which is consistent with other Ajuga species. Our phylogenetic analysis revealed that A. spectabilis formed a close relationship with A. ciliata and A. decumbens.

REDD1 promotes obesity-induced metabolic dysfunction via atypical NF-κB activation.

Regulated in development and DNA damage response 1 (REDD1) expression is upregulated in response to metabolic imbalance and obesity. However, its role in obesity-associated complications is unclear. Here, we demonstrate that the REDD1-NF-κB axis is crucial for metabolic inflammation and dysregulation. Mice lacking Redd1 in the whole body or adipocytes exhibited restrained diet-induced obesity, inflammation, insulin resistance, and hepatic steatosis. Myeloid Redd1-deficient mice showed similar results, without restrained obesity and hepatic steatosis. Redd1-deficient adipose-derived stem cells lost their potential to differentiate into adipocytes; however, REDD1 overexpression stimulated preadipocyte differentiation and proinflammatory cytokine expression through atypical IKK-independent NF-κB activation by sequestering IκBα from the NF-κB/IκBα complex. REDD1 with mutated Lys219/220Ala, key amino acid residues for IκBα binding, could not stimulate NF-κB activation, adipogenesis, and inflammation in vitro and prevented obesity-related phenotypes in knock-in mice. The REDD1-atypical NF-κB activation axis is a therapeutic target for obesity, meta-inflammation, and metabolic complications.

PPARδ Agonist Promotes Type II Cartilage Formation in a Rabbit Osteochondral Defect Model.

Osteoarthritis (OA) is a chronic degenerative joint disease accompanied by an inflammatory milieu that results in painful joints. The pathogenesis of OA is multifactorial, with genetic predisposition, environmental factors, and traumatic injury resulting in the direct or indirect loss of cartilage. The articular cartilage can also be damaged by direct focal traumatic injury. Articular cartilage provides a smooth, deformable bearing surface with a low coefficient of friction, increased contact area, and reduced contact stress. Articular type II hyaline cartilage lines the synovial joints and, when injured, has a limited ability for repair, except for the most superficial layers via diffusion from the synovial fluid, secondary to no blood supply, a complex structure, and a low metabolic rate. Restoring the articular surface can relieve pain and restore function. Although many strategies have been developed to regenerate type II collagen based on the extent of the lesion, surgical treatments are still evolving. The peroxisome proliferator-activated receptor delta (PPARδ) agonist and collagen treatment of mesenchymal stem cells (MSCs) enhance the chondrogenic capacity in vitro. We present a novel technique for cartilage restoration in a rabbit cartilage osteochondral defect model using a PPARδ agonist (GW0742)-infused 3D collagen scaffold to induce type II cartilage from MSCs.

Genetic structure and geneflow of Malus across the Korean Peninsula using genotyping-by-sequencing.

This study was to understand the genetic structure and diversity of the Korean Malus species. We used genotyping-by-sequencing (GBS) technology to analyze samples of 112 individuals belonging to 18 populations of wild Malus spp. Using GBS, we identified thousands of single nucleotide polymorphisms in the species analyzed. M. baccata and M. toringo, two dominant mainland species of the Korean Peninsula, were distinguishable based on their genetic structure. However, M. toringo collected from Jeju Island exhibited a different genetic profile than that from the mainland. We identified M. cf. micromalus as a hybrid resulting from the Jeju Island M. toringo (pollen donor) and the mainland M. baccata, (pollen recipient). Putative M. mandshurica distributed on the Korean Peninsula showed a high structural and genetic similarity with M. baccata, indicating that it might be an ecotype. Overall, this study contributes to the understanding of the population history and genetic structure of Malus in the Korean Peninsula.

A laser parameter study on enhancing proton generation from microtube foil targets.

The interaction of an intense laser with a solid foil target can drive [Formula: see text] TV/m electric fields, accelerating ions to MeV energies. In this study, we experimentally observe that structured targets can dramatically enhance proton acceleration in the target normal sheath acceleration regime. At the Texas Petawatt Laser facility, we compared proton acceleration from a [Formula: see text] flat Ag foil, to a fixed microtube structure 3D printed on the front side of the same foil type. A pulse length (140-450 fs) and intensity ((4-10) [Formula: see text] W/cm[Formula: see text]) study found an optimum laser configuration (140 fs, 4 [Formula: see text] W/cm[Formula: see text]), in which microtube targets increase the proton cutoff energy by 50% and the yield of highly energetic protons ([Formula: see text] MeV) by a factor of 8[Formula: see text]. When the laser intensity reaches [Formula: see text] W/cm[Formula: see text], the prepulse shutters the microtubes with an overcritical plasma, damping their performance. 2D particle-in-cell simulations are performed, with and without the preplasma profile imported, to better understand the coupling of laser energy to the microtube targets. The simulations are in qualitative agreement with the experimental results, and show that the prepulse is necessary to account for when the laser intensity is sufficiently high.

Phylogenetic relationship, biogeography, and conservation genetics of endangered Fraxinus chiisanensis (Oleaceae), endemic to South Korea.

Endemic plants are important for understanding phylogenetic relationships, biogeographical history, and genetic variation because of their restricted distribution and their role in conserving biodiversity. Here, we investigated the phylogenetic relationships of the Korean endemic Fraxinus chiisanensis by reconstructing the molecular phylogeny of Fraxinus based on two nuclear DNA (nrITS and phantastica) and two chloroplast DNA (psbA-trnH and rpl32-trnL) regions. Within our fossil-calibrated phylogenetic framework, we also inferred the biogeographical history of F. chiisanensis. To provide a scientific basis for the conservation of F. chiisanensis, we determined the levels of genetic diversity and genetic differentiation in this species. Combining information from nuclear and chloroplast DNA sequence data, our molecular phylogenetic analyses identified F. chiisanensis as a genetically distinct unit from its sister group, Fraxinus platypoda from Japan. Our molecular dating analyses using nuclear and chloroplast DNA data sets show F. chiisanensis diverged from its sister F. platypoda in the Early or Middle Miocene and differentiated in the Late Miocene on the Korean Peninsula. Our results suggest that the divergence of F. chiisanensis was associated with the submergence of the East China Sea land bridge and enhanced monsoons in East Asia. When compared to F. platypoda, F. chiisanensis exhibits low genetic diversity within populations and high genetic differentiation among populations. These results help us to understand the evolutionary history of F. chiisanensis and to develop a conservation strategy for this species.

Molecular Phylogeny and Historical Biogeography of Goodyera R. Br. (Orchidaceae): A Case of the Vicariance Between East Asia and North America.

Understanding of intercontinental distribution in the Northern Hemisphere has attracted a lot of attention from botanists. However, although Orchidaceae is the largest group of angiosperms, biogeographical studies on the disjunctive pattern have not been sufficient for this family. Goodyera R. Br. (tribe Cranichideae, subfamily Orchidoideae, family Orchidaceae) is widely distributed in temperate and tropical regions. Although the phylogenetic relationship of Goodyera inferred from both morphological and molecular data has been conducted, the sampled taxa were mainly distributed in Asia regions that resulted in non-monophyly of this genus. In this study, the complete plastid genomes of Goodyera, generated by next-generation sequencing (NGS) technique and sampled in East Asia and North America, were used to reconstruct phylogeny and explore the historical biogeography. A total of 18 Goodyera species including seven newly sequenced species were analyzed. Based on 79 protein-coding genes, the phylogenetic analysis revealed that Goodyera could be subdivided into four subclades with high support values. The polyphyletic relationships among Goodyera taxa were confirmed, and the unclear position of G. foliosa was also resolved. The datasets that are composed of the 14 coding sequences (CDS) (matK, atpF, ndhK, accD, cemA, clpP, rpoA, rpl22, ndhF, ccsA, ndhD, ndhI, ndhA, and ycf 1) showed the same topology derived from 79 protein-coding genes. Molecular dating analyses revealed the origin of Goodyera in the mid-Miocene (15.75 Mya). Nearctic clade of Goodyera was diverged at 10.88 Mya from their most recent common ancestor (MRCA). The biogeographical reconstruction suggests that subtropical or tropical Asia is the origin of Goodyera and it has subsequently spread to temperate Asia during the Miocene. In addition, Nearctic clade is derived from East Asian species through Bering Land Bridge (BLB) during the Miocene. The speciation of Goodyera is most likely to have occurred during Miocene, and climatic and geological changes are thought to have had a part in this diversification. Our findings propose both origin and vicariance events of Goodyera for the first time and add an example for the biogeographical history of the Northern Hemisphere.

Disjunction and Vicariance Between East and West Asia: A Case Study on Euonymus sect. Uniloculares Based on Plastid Genome Analysis.

Scientists have long been captivated by biogeographic disjunctions, and disjunctions between East Asia and North America have been particularly well-studied at the genus and family levels. By contrast, disjunctions between eastern and western Asia have received less attention. Euonymus L. is taxonomically divided into two sections based on the number of cells in anthers as follows: E. sect. Uniloculares has one-celled anthers and occurs mainly in Asia, whereas E. sect. Biloculares has two-celled anthers and is distributed globally. We used Illumina sequencing to investigate the genomes of four species in sect. Uniloculares. The chloroplast (cp) genomes are highly conserved (157,290-158,094 bp). Pseudogenisation of ndhF and intron loss in rps16 was detected. Based on the cp genomes of the four species of E. sect. Uniloculares, we propose a novel hypothesis of disjunction between eastern and western Asia. Biogeographic reconstruction and molecular dating revealed that sect. Uniloculares separated from its sect. Biloculares forebears 4.0 Mya during the Pliocene era. The radial diversification of sect. Uniloculares from East Asia and the establishment of the western Asian clade during the Pleistocene era (1.9 Mya) were the results of both dispersal and vicariance, making the section the youngest diverged clade conforming to age estimation. The centre of origin of sect. Uniloculares was determined to be in East Asia. Disjunctions and diversification between eastern and western Asia in sect. Uniloculares are thought to have been caused by changes in monsoon patterns, temperature variations, and the emergence of the Gobi Desert.