Spatiotemporal transcriptomic atlas of mouse organogenesis using DNA nanoball-patterned arrays.

Spatially resolved transcriptomic technologies are promising tools to study complex biological processes such as mammalian embryogenesis. However, the imbalance between resolution, gene capture, and field of view of current methodologies precludes their systematic application to analyze relatively large and three-dimensional mid- and late-gestation embryos. Here, we combined DNA nanoball (DNB)-patterned arrays and in situ RNA capture to create spatial enhanced resolution omics-sequencing (Stereo-seq). We applied Stereo-seq to generate the mouse organogenesis spatiotemporal transcriptomic atlas (MOSTA), which maps with single-cell resolution and high sensitivity the kinetics and directionality of transcriptional variation during mouse organogenesis. We used this information to gain insight into the molecular basis of spatial cell heterogeneity and cell fate specification in developing tissues such as the dorsal midbrain. Our panoramic atlas will facilitate in-depth investigation of longstanding questions concerning normal and abnormal mammalian development.

A Common Embryonic Origin of Stem Cells Drives Developmental and Adult Neurogenesis.

New neurons arise from quiescent adult neural progenitors throughout life in specific regions of the mammalian brain. Little is known about the embryonic origin and establishment of adult neural progenitors. Here, we show that Hopx+ precursors in the mouse dentate neuroepithelium at embryonic day 11.5 give rise to proliferative Hopx+ neural progenitors in the primitive dentate region, and they, in turn, generate granule neurons, but not other neurons, throughout development and then transition into Hopx+ quiescent radial glial-like neural progenitors during an early postnatal period. RNA-seq and ATAC-seq analyses of Hopx+ embryonic, early postnatal, and adult dentate neural progenitors further reveal common molecular and epigenetic signatures and developmental dynamics. Together, our findings support a "continuous" model wherein a common neural progenitor population exclusively contributes to dentate neurogenesis throughout development and adulthood. Adult dentate neurogenesis may therefore represent a lifelong extension of development that maintains heightened plasticity in the mammalian hippocampus.

The rise of baobab trees in Madagascar.

The baobab trees (genus Adansonia) have attracted tremendous attention because of their striking shape and distinctive relationships with fauna1. These spectacular trees have also influenced human culture, inspiring innumerable arts, folklore and traditions. Here we sequenced genomes of all eight extant baobab species and argue that Madagascar should be considered the centre of origin for the extant lineages, a key issue in their evolutionary history2,3. Integrated genomic and ecological analyses revealed the reticulate evolution of baobabs, which eventually led to the species diversity seen today. Past population dynamics of Malagasy baobabs may have been influenced by both interspecific competition and the geological history of the island, especially changes in local sea levels. We propose that further attention should be paid to the conservation status of Malagasy baobabs, especially of Adansonia suarezensis and Adansonia grandidieri, and that intensive monitoring of populations of Adansonia za is required, given its propensity for negatively impacting the critically endangered Adansonia perrieri.

Fibroblast growth factor 13 is a microtubule-stabilizing protein regulating neuronal polarization and migration.

Secretory fibroblast growth factors (FGFs) and their receptors are known for their regulatory function in the early stages of neural development. FGF13, a nonsecretory protein of the FGF family, is expressed in cerebral cortical neurons during development and is a candidate gene for syndromal and nonspecific forms of X-chromosome-linked mental retardation (XLMR). However, its function during development remains unclear. We show that FGF13 acts intracellularly as a microtubule-stabilizing protein required for axon and leading process development and neuronal migration in the cerebral cortex. FGF13 is enriched in axonal growth cones and interacts directly with microtubules. Furthermore, FGF13 polymerizes tubulins and stabilizes microtubules. The loss of FGF13 impairs neuronal polarization and increases the branching of axons and leading processes. Genetic deletion of FGF13 in mice results in neuronal migration defects in both the neocortex and the hippocampus. FGF13-deficient mice also exhibit weakened learning and memory, which is correlated to XLMR patients' intellectual disability.

MicroRNA397 promotes rice flowering by regulating the photorespiration pathway.

The precise timing of flowering plays a pivotal role in ensuring successful plant reproduction and seed production. This process is intricately governed by complex genetic networks that integrate internal and external signals. This study delved into the regulatory function of microRNA397 (miR397) and its target gene LACCASE-15 (OsLAC15) in modulating flowering traits in rice (Oryza sativa). Overexpression of miR397 led to earlier heading dates, decreased number of leaves on the main stem, and accelerated differentiation of the spikelet meristem. Conversely, overexpression of OsLAC15 resulted in delayed flowering and prolonged vegetative growth. Through biochemical and physiological assays, we uncovered that miR397-OsLAC15 had a profound impact on carbohydrate accumulation and photosynthetic assimilation, consequently enhancing the photosynthetic intensity in miR397-overexpressing rice plants. Notably, we identified that OsLAC15 is at least partially localized within the peroxisome organelle, where it regulates the photorespiration pathway. Moreover, we observed that a high CO2 concentration could rescue the late flowering phenotype in OsLAC15-overexpressing plants. These findings shed valuable insights into the regulatory mechanisms of miR397-OsLAC15 in rice flowering and provided potential strategies for developing crop varieties with early flowering and high-yield traits through genetic breeding.

KAT8/SIRT7-mediated Fascin-K41 acetylation/deacetylation regulates tumor metastasis in esophageal squamous cell carcinoma.

Fascin actin-bundling protein 1 (Fascin) is highly expressed in a variety of cancers, including esophageal squamous cell carcinoma (ESCC), working as an important oncogenic protein and promoting the migration and invasion of cancer cells by bundling F-actin to facilitate the formation of filopodia and invadopodia. However, it is not clear how exactly the function of Fascin is regulated by acetylation in cancer cells. Here, in ESCC cells, the histone acetyltransferase KAT8 catalyzed Fascin lysine 41 (K41) acetylation, to inhibit Fascin-mediated F-actin bundling and the formation of filopodia and invadopodia. Furthermore, NAD-dependent protein deacetylase sirtuin (SIRT) 7-mediated deacetylation of Fascin-K41 enhances the formation of filopodia and invadopodia, which promotes the migration and invasion of ESCC cells. Clinically, the analysis of cancer and adjacent tissue samples from patients with ESCC showed that Fascin-K41 acetylation was lower in the cancer tissue of patients with lymph node metastasis than in that of patients without lymph node metastasis, and low levels of Fascin-K41 acetylation were associated with a poorer prognosis in patients with ESCC. Importantly, K41 acetylation significantly blocked NP-G2-044, one of the Fascin inhibitors currently being clinically evaluated, suggesting that NP-G2-044 may be more suitable for patients with low levels of Fascin-K41 acetylation, but not suitable for patients with high levels of Fascin-K41 acetylation. © 2024 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

An epigenetic circuit controls neurogenic programs during neocortex development.

The production and expansion of intermediate progenitors (IPs) are essential for neocortical neurogenesis during development and over evolution. Here, we have characterized an epigenetic circuit that precisely controls neurogenic programs, particularly properties of IPs, during neocortical development. The circuit comprises a long non-coding RNA (LncBAR) and the BAF (SWI/SNF) chromatin-remodeling complex, which transcriptionally maintains the expression of Zbtb20. LncBAR knockout neocortex contains more deep-layer but fewer upper-layer projection neurons. Intriguingly, loss of LncBAR promotes IP production, but paradoxically prolongs the duration of the cell cycle of IPs during mid-later neocortical neurogenesis. Moreover, in LncBAR knockout mice, depletion of the neural progenitor pool at embryonic stage results in fewer adult neural progenitor cells in the subventricular zone of lateral ventricles, leading to a failure in adult neurogenesis to replenish the olfactory bulb. LncBAR binds to BRG1, the core enzymatic component of the BAF chromatin-remodeling complex. LncBAR depletion enhances association of BRG1 with the genomic locus of, and suppresses the expression of, Zbtb20, a transcription factor gene known to regulate both embryonic and adult neurogenesis. ZBTB20 overexpression in LncBAR-knockout neural precursors reverses compromised cell cycle progressions of IPs.

Climatic niche evolution and niche conservatism of Nymphaea species in Africa, South America, and Australia.

BACKGROUND: Interest in the evolution of climatic niches, particularly in understanding the potential adaptive responses of species under climate change, has increased both theoretically and within macroecological studies. These studies have provided valuable insights into how climatic traits of species influence their niche evolution. In this study, we aim to investigate whether niche conservatism plays a role in the species diversification of Nymphaea, a group of aquatic plants with a cosmopolitan distribution that is facing severe habitat loss. We will use climatic models and phylogenetic data for 23 species to reconstruct Nymphaea's niche evolution, measure niche overlap, and assess disparity through time while testing for evolutionary models. RESULTS: There was a lot of overlap in niches both within and between groups, especially for species that can be found in many places. The breadth and peaks of the niche profile varied depending on the bioclimatic variables, which suggested that the species evolved differently to cope with changes in climate. The analysis also showed that evolutionary changes happened across the phylogeny, with weak to moderate signals. The morphological disparity index (MDI) values indicated that there were disparities within subclades over time but not between or among them. Niche reconstruction and evolution analysis revealed both convergent and divergent evolution among various variables. For example, N. immutabilis, N. atrans, N. violancea, and N. nouchali evolved towards intermediate temperatures for bio2 and bio3 (isothermity) while moving towards extreme temperatures for bio8 and bio9 (wettest and driest average quarterly temperatures). CONCLUSION: Our study will improve our understanding of how changes in climatic niches are potentially driving the evolution of Nymphaea. It has significant scientific implications for the limits, assemblages, evolution, and diversification of species. This information is crucial for the ongoing efforts of conservation and management, particularly considering the inevitable effects of climate change.

Controllable nonreciprocal phonon laser in a hybrid photonic molecule based on directional quantum squeezing.

Here, a scheme for a controllable nonreciprocal phonon laser is proposed in a hybrid photonic molecule system consisting of a whispering-gallery mode (WGM) optomechanical resonator and a χ(2)-nonlinear WGM resonator, by directionally quantum squeezing one of two coupled resonator modes. The directional quantum squeezing results in a chiral photon interaction between the resonators and a frequency shift of the squeezed resonator mode with respect to the unsqueezed bare mode. We show that the directional quantum squeezing can modify the effective optomechanical coupling in the optomechanical resonator, and analyze the impacts of driving direction and squeezing extent on the phonon laser action in detail. Our analytical and numerical results indicate that the controllable nonreciprocal phonon laser action can be effectively realized in this system. The proposed scheme uses an all-optical and chip-compatible approach without spinning resonators, which may be more beneficial for integrating and packaging of the system on a chip. Our proposal may provide a new route to realize integratable phonon devices for on-chip nonreciprocal phonon manipulations, which may be used in chiral quantum acoustics, topological phononics, and acoustical information processing.

Universal Spin Superconducting Diode Effect from Spin-Orbit Coupling.

We propose a universal spin superconducting diode effect (SDE) induced by spin-orbit coupling (SOC) in systems with spin-triplet correlations, where the critical spin supercurrents in opposite directions are unequal. By analysis from both the Ginzburg-Landau theory and energy band analysis, we show that the spin-↑↑ and spin-↓↓ Cooper pairs possess opposite phase gradients and opposite momenta from the SOC, which leads to the spin SDE. Two superconductors with SOC, a p-wave superconductor as a toy model and a practical superconducting nanowire, are numerically studied and they both exhibit spin SDE. In addition, our theory also provides a unified picture for both spin and charge SDEs.

Photoredox Catalyzed Radical Fluoroalkylation with Non-Classical Fluorinated Reagents.

The emergence of photocatalysis has greatly advanced radical fluoroalkylation reactions. Central to this advancement is the introduction and refinement of radical reagents, which play a pivotal role in driving these reactions forward. Intriguingly, some of these reagents, previously not recognized for their radical properties, have emerged as key players in this area. In this Perspective, we provide an overview of four representative reagents pioneered by our laboratory, which have subsequently garnered extensive application in broader research contexts, including difluorocarbene precursors bromodifluoromethylphosphonium bromide, electrophilic sulfonylation reagent triflic anhydride, and nucleophilic trifluoromethylation reagent methyl fluorosulfonyldifluoroacetate (Chen's reagent). The integration of phosphonium reagents, triflic anhydride, and methyl fluorosulfonyldifluoroacetate into photocatalysis has enabled some unexpected reactivities and now notably expanded the capabilities in radical difluoromethylation, trifluoromethylation, and difluoroalkylation. Our discussion highlights how these atypical reagents have enriched the toolkit available for radical fluoroalkylations, offering insights that could inspire future research and application in this area.

BCL6 attenuates hyperoxia-induced lung injury by inhibiting NLRP3-mediated inflammation in fetal mouse.

BACKGROUND: The transcriptional repressor B-cell lymphoma 6 (BCL6) has been reported to inhibit inflammation. So far, experimental evidence for the role of BCL6 in bronchopulmonary dysplasia (BPD) is lacking. Our study investigated the roles of BCL6 in the progression of BPD and its downstream mechanisms. METHODS: Hyperoxia or lipopolysaccharide (LPS) was used to mimic the BPD mouse model. To investigate the effects of BCL6 on BPD, recombination adeno-associated virus serotype 9 expressing BCL6 (rAAV9-BCL6) and BCL6 inhibitor FX1 were administered in mice. The pulmonary pathological changes, inflammatory chemokines and NLRP3-related protein were observed. Meanwhile, BCL6 overexpression plasmid was used in human pulmonary microvascular endothelial cells (HPMECs). Cell proliferation, apoptosis, and NLRP3-related protein were detected. RESULTS: Either hyperoxia or LPS suppressed pulmonary BCL6 mRNA expression. rAAV9-BCL6 administration significantly inhibited hyperoxia-induced NLRP3 upregulation and inflammation, attenuated alveolar simplification and dysregulated angiogenesis in BPD mice, which were characterized by decreased mean linear intercept, increased radical alveolar count and alveoli numbers, and the upregulated CD31 expression. Meanwhile, BCL6 overexpression promoted proliferation and angiogenesis, inhibited apoptosis and inflammation in hyperoxia-stimulated HPMECs. Moreover, administration of BCL6 inhibitor FX1 arrested growth and development. FX1-treated BPD mice exhibited exacerbation of alveolar pathological changes and pulmonary vessel permeability, with upregulated mRNA levels of pro-inflammatory cytokines and pro-fibrogenic factors. Furthermore, both rAAV9-BCL6 and FX1 administration exerted a long-lasting effect on hyperoxia-induced lung injury (≥4 wk). CONCLUSIONS: BCL6 inhibits NLRP3-mediated inflammation, attenuates alveolar simplification and dysregulated pulmonary vessel development in hyperoxia-induced BPD mice. Hence, BCL6 may be a target in treating BPD and neonatal diseases.

Comparative Proteome and Cis-Regulatory Element Analysis Reveals Specific Molecular Pathways Conserved in Dog and Human Brains.

Brain development and function are governed by precisely regulated protein expressions in different regions. To date, multiregional brain proteomes have been systematically analyzed only for adult human and mouse brains. To understand the underpinnings of brain development and function, we generated proteomes from six regions of the postnatal brain at three developmental stages of domestic dogs (Canis familiaris), which are special among animals in terms of their remarkable human-like social cognitive abilities. Quantitative analysis of the spatiotemporal proteomes identified region-enriched synapse types at different developmental stages and differential myelination progression in different brain regions. Through integrative analysis of inter-regional expression patterns of orthologous proteins and genome-wide cis-regulatory element frequencies, we found that proteins related with myelination and hippocampus were highly correlated between dog and human but not between mouse and human, although mouse is phylogenetically closer to human. Moreover, the global expression patterns of neurodegenerative disease and autism spectrum disorder-associated proteins in dog brain more resemble human brain than in mouse brain. The high similarity of myelination and hippocampus-related pathways in dog and human at both proteomic and genetic levels may contribute to their shared social cognitive abilities. The inter-regional expression patterns of disease-associated proteins in the brain of different species provide important information to guide mechanistic and translational study using appropriate animal models.

Diagnostic performance of coronary computed tomography angiography stenosis score for coronary stenosis.

BACKGROUND: Coronary computed tomography angiography stenosis score (CCTA-SS) is a proposed diagnosis score that considers the plaque characteristics, myocardial function, and the diameter reduction rate of the lesions. This study aimed to evaluate the diagnostic performance of the CCTA-SS in seeking coronary artery disease (CAD). METHODS: The 228 patients with suspected CAD who underwent CCTA and invasive coronary angiography (ICA) procedures were under examination. The diagnostic performance was evaluated with the receiver operating curve (ROC) for CCTA-SS in detecting CAD (defined as a diameter reduction of ≥ 50%) and severe CAD (defined as a diameter reduction of ≥ 70%). RESULTS: The area under ROC (AUC) of CCTA-SS was 0.909 (95% CI: 0.864-0.943), which was significantly higher than that of CCTA (AUC: 0.826; 95% CI: 0.771-0.873; P = 0.0352) in diagnosing of CAD with a threshold of 50%. The optimal cutoff point of CCTA-SS was 51% with a sensitivity of 90.66%, specificity of 95.65%, positive predictive value of 98.80%, negative predictive value of 72.13%, and accuracy of 91.67%, whereas the optimal cutoff point of CCTA was 55%, and the corresponding values were 87.36%, 93.48%, 98.15%, 65.15%, and 88.60%, respectively. With a threshold of 70%, the performance of CCTA-SS with an AUC of 0.927 (95% CI: 0.885-0.957) was significantly higher than that of CCTA with an AUC of 0.521 (95% CI: 0.454-0.587) (P < 0.0001). CONCLUSIONS: CCTA-SS significantly improved the diagnostic accuracy of coronary stenosis, including CAD and severe CAD, compared with CCTA.

Clinical features and surgical treatments of scoliosis in neurofibromatosis type 1: a systemic review and meta-analysis.

BACKGROUND: Neurofibromatosis type 1 (NF 1) is an autosomal-dominant tumor predisposition genetic disease affecting approximately 1 in 3000 live births. The condition could present various manifestations ranging from skin abnormalities to neurological tumors. The musculoskeletal system could also be frequently affected, and scoliosis is the most common orthopedic manifestation. Characterized by the early-onset and rapid progression tendency, NF 1-related dystrophic scoliosis presented discrepancies from idiopathic scoliosis in terms of natural history, clinical features, and management outcomes and thus required special attention. In the current study, the authors conducted a systemic review to outline the body of evidence of the natural history, clinical characteristics, surgical outcomes, and surgical complications of NF 1-induced scoliosis, aiming to provide an elucidative insight into this condition. METHOD: Systemic review and meta-analysis were conducted according to the latest Preferred Reporting Items for Systematic Reviews Meta-Analyses (PRISMA) guidelines. The search was performed in Medline, Embase, and Web of Science Core Collection up to December 27, 2022, using related keywords. Clinical features such as frequencies, segmental involvement, and hereditary information were summarized and described qualitatively. Meta-analysis was conducted using R software and the 'meta' package to yield an overall outcome of efficacy and safety of surgical management, precisely, spinal fusion procedure and growing rods procedure. Corrective rate of Cobb angle, sagittal kyphosis angle, and T1-S1 length post-operative and at the last follow-up was used to evaluate the efficacy, and the occurrence of surgery-related complications was used to evaluate the safety. RESULT: A total of 37 articles involving 1023 patients were included. Approximately 26.6% of the NF 1 patients would present with scoliosis. Patients tend to develop scoliosis at an earlier age. The thoracic part turned out to be the most affected segment. No obvious correlation between scoliosis and genotype or hereditary type was observed. Both spinal fusion and growing rod surgery have shown acceptable treatment outcomes, with spinal fusion demonstrating better performance in terms of effectiveness and safety. The growing rods technique seemed to allow a better lengthening of the spine. The mainstay post-operative complications were implant-related complications but could be managed with limited revision surgery. Severe neurological deficits were rarely reported. CONCLUSION: Scoliosis, especially the subtype characterized by dystrophic bony changes, is a significant orthopedic manifestation of NF1. It has an early onset, a tendency to persistently and rapidly progress, and is challenging to deal with. The current review outlines the available evidence from the perspective of natural history, clinical features, and the treatment efficacy and safety of the mainstay surgical options. Patients with NF1 scoliosis will benefit from a better understanding of the disease and evidence based treatment strategies.

Promotion of self-directed learning abilities among Chinese medical students through preparing for career calling and enhancing teaching competencies in medical education: a cross-sectional study.

BACKGROUND: Medical students face a heavy burden as they are tasked with acquiring a vast amount of medical knowledge within a limited time frame. Self-directed learning (SDL) has become crucial for efficient and ongoing learning among medical students. However, effective ways to foster SDL ability among Chinese medical students are lacking, and limited studies have identified factors that impact the SDL ability of medical students. This makes it challenging for educators to develop targeted strategies to improve students' SDL ability. This study aims to assess SDL ability among Chinese medical students and examine the effects of career calling and teaching competencies on SDL ability, as well as the possible mechanisms linking them. METHODS: Data were collected from 3614 respondents (effective response rate = 60.11%) using cross-sectional online questionnaires and analyzed using IBM SPSS Statistics 22.0. The questionnaire comprised a Demographic Characteristics Questionnaire, Self-directed Learning Ability Scale (Cronbach's alpha = 0.962), Teaching Competencies Scale, and Career Calling Scale. RESULTS: The average SDL ability score of Chinese medical students was 3.68 ± 0.56, indicating a moderate level of SDL ability. The six factors of the Self-directed Learning Ability Scale-self-reflection, ability to use learning methods, ability to set study plans, ability to set studying objectives, ability to adjust psychological state, and willpower in studying-accounted for 12.90%, 12.89%, 12.39%, 11.94%, 11.34%, and 8.67% of the variance, respectively. Furthermore, career calling was positively associated with SDL learning ability (ß = 0.295, p < 0.001), and SDL learning ability was positively associated with teaching competencies (ß = 0.191, p < 0.01). Simple slope analysis showed that when the level of teaching competencies was higher, the influence of career calling on SDL ability was stronger. CONCLUSIONS: Chinese medical students' SDL ability has room for improvement. Medical students could strengthen their willpower in studying by setting milestones goals with rewards, which could inspire their motivation for the next goals. Teachers should guide students to learn experience to improve students' reflective ability. Educators play a crucial role in bridging the gap between career calling education and SDL ability enhancement, highlighting the significance of optimal teaching competencies. Colleges should focus on strengthening teachers' sense of career calling and teaching competencies.

Acupuncture versus tricyclic antidepressants in the prophylactic treatment of tension-type headaches: an indirect treatment comparison meta-analysis.

BACKGROUND: Acupuncture showed better improvement than sham acupuncture in reducing attack frequency of tension-type headache (TTH), but its effectiveness relative to first-line drugs for TTH is unknown, which impedes the recommendation of acupuncture for patients who are intolerant to drugs for TTH. We aimed to estimate the relative effectiveness between acupuncture and tricyclic antidepressants (TCAs) through indirect treatment comparison (ITC) meta-analysis. METHODS: We searched Ovid Medline, Embase, and Cochrane Library from database inception until April 13, 2023. Randomized controlled trials of TCAs or acupuncture in the prevention of TTH in adults were included. The primary outcome was headache frequency. The secondary outcomes were headache intensity, responder rate, and adverse event rate. Bayesian random-effect models were used to perform ITC meta-analysis, and confidence of evidence was evaluated by using the GRADE approach. RESULTS: A total of 34 trials involving 4426 participants were included. Acupuncture had similar effect with TCAs in decreasing TTH frequency (amitriptyline: mean difference [MD] -1.29, 95% CI -5.28 to 3.02; amitriptylinoxide: MD -0.05, 95% CI -6.86 to 7.06) and reducing TTH intensity (amitriptyline: MD 2.35, 95% CI -1.20 to 5.78; clomipramine: MD 1.83, 95% CI -4.23 to 8.20). Amitriptyline had a higher rate of adverse events than acupuncture (OR 4.73, 95% CI 1.42 to 14.23). CONCLUSION: Acupuncture had similar effect as TCAs in reducing headache frequency of TTH, and acupuncture had a lower adverse events rate than amitriptyline, as shown by very low certainty of evidence.

Reversal of the Regioselectivity of Iron-Promoted Hydrogenation and Hydrohalogenation of gem-Difluoroalkenes.

The reaction regioselectivity of gem-difluoroalkenes is dependent on the intrinsic polarity. Thus, the reversal of the regioselectivity of the addition reaction of gem-difluoroalkenes remains a formidable challenge. Herein, we described an unprecedented reversal of regioselectivity of hydrogen atom transfer (HAT) to gem-difluoroalkenes triggered by Fe-H species for the formation of difluoroalkyl radicals. Hydrogenation of the in situ generated radicals gave difluoromethylated products. Mechanism experiments and theoretical studies revealed that the kinetic effect of the irreversible HAT process resulted in the reversal of the regioselectivity of this scenario, leading to the formation of a less stable α-difluoroalkyl radical regioisomer. On basis of this new reaction of gem-difluoroalkene, the iron-promoted hydrohalogenation of gem-difluoroalkenes for the efficient synthesis of aliphatic chlorodifluoromethyl-, bromodifluoromethyl- and iododifluoromethyl-containing compounds was developed. Particularly, this novel hydrohalogenation of gem-difluoroalkenes provided an effect and large-scale access to various iododifluoromethylated compounds of high value for synthetic application.

Copper-Mediated Oxidative Chloro- and Bromodifluoromethylation of Phenols.

The first oxidative chloro- and bromodifluoromethylation of phenols with (CH3)3SiCF2X and CuX (X = Cl or Br) in the presence of Selectfluor under mild reaction conditions was developed. This protocol provided a practical and efficient method for the synthesis of a diverse range of biologically valuable and synthetically challenging chloro- and bromodifluoromethyl aryl ethers. Preliminary mechanistic studies suggest that this reaction proceeded through a difluorocarbene-involved oxidative coupling process.

Phylogenomic Analyses of Alismatales Shed Light into Adaptations to Aquatic Environments.

Land plants first evolved from freshwater algae, and flowering plants returned to water as early as the Cretaceous and multiple times subsequently. Alismatales is the largest clade of aquatic angiosperms including all marine angiosperms, as well as terrestrial plants. We used Alismatales to explore plant adaptations to aquatic environments by analyzing a data set that included 95 samples (89 Alismatales species) covering four genomes and 91 transcriptomes (59 generated in this study). To provide a basis for investigating adaptations, we assessed phylogenetic conflict and whole-genome duplication (WGD) events in Alismatales. We recovered a relationship for the three main clades in Alismatales as (Tofieldiaceae, Araceae) + core Alismatids. We also found phylogenetic conflict among the three main clades that was best explained by incomplete lineage sorting and introgression. Overall, we identified 18 putative WGD events across Alismatales. One of them occurred at the most recent common ancestor of core Alismatids, and three occurred at seagrass lineages. We also found that lineage and life-form were both important for different evolutionary patterns for the genes related to freshwater and marine adaptation. For example, several light- or ethylene-related genes were lost in the seagrass Zosteraceae, but are present in other seagrasses and freshwater species. Stomata-related genes were lost in both submersed freshwater species and seagrasses. Nicotianamine synthase genes, which are important in iron intake, expanded in both submersed freshwater species and seagrasses. Our results advance the understanding of the adaptation to aquatic environments and WGDs using phylogenomics.