Characterization of a predictive signature for tumor microenvironment and immunotherapy response in hepatocellular carcinoma involving neutrophil extracellular traps.

Neutrophil extracellular traps (NETs) and other factors play a significant role in impacting the prognosis of patients with Hepatocellular carcinoma (HCC). Nevertheless, further research is warranted to fully elucidate the prognostic implications of NETs in patients with HCC. We employed a hierarchical clustering technique to examine the Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) data and identified subtypes associated with NETs. Subsequently, we utilized LASSO regression analysis to identify a distinct gene expression pattern within these subtypes. The strength of this signature was further validated through analysis of TCGA-LIHC and International Cancer Genome Consortium-Liver Cancer (ICGC-LIRI-JP) data. Our findings resulted in the construction of a six-gene signature related to NETs, which can predict survival outcomes in HCC patients. To enhance the predictive accuracy of our tool, we developed a nomogram that integrates the NETs signature with clinicopathological characteristics. We validated the significance of NETs in HCC patients using qRT-PCR and immunohistochemistry assays, along with in vitro experiments targeting high-risk genes. Furthermore, our exploration of the immune microenvironment uncovered augmented immune-specific metrics within the low-risk cohort, implying potential disparities in immune-related attributes between the high-risk and low-risk contingents. In summary, the NETs signature we discovered serves as a valuable biomarker and provides guidance for personalized therapy in HCC patients.

Insights into spinach domestication from genome sequences of two wild spinach progenitors, Spinacia turkestanica and Spinacia tetrandra.

Cultivated spinach (Spinacia oleracea) is a dioecious species. We report high-quality genome sequences for its two closest wild relatives, Spinacia turkestanica and Spinacia tetrandra, which are also dioecious, and are used to study the genetics of spinach domestication. Using a combination of genomic approaches, we assembled genomes of both these species and analyzed them in comparison with the previously assembled S. oleracea genome. These species diverged c. 6.3 million years ago (Ma), while cultivated spinach split from S. turkestanica 0.8 Ma. In all three species, all six chromosomes include very large gene-poor, repeat-rich regions, which, in S. oleracea, are pericentromeric regions with very low recombination rates in both male and female genetic maps. We describe population genomic evidence that the similar regions in the wild species also recombine rarely. We characterized 282 structural variants (SVs) that have been selected during domestication. These regions include genes associated with leaf margin type and flowering time. We also describe evidence that the downy mildew resistance loci of cultivated spinach are derived from introgression from both wild spinach species. Collectively, this study reveals the genome architecture of spinach assemblies and highlights the importance of SVs during the domestication of cultivated spinach.

Apigenin 7-glucoside impedes hypoxia-induced malignant phenotypes of cervical cancer cells in a p16-dependent manner.

Apigenin 7-glucoside (A7G) can suppress cell proliferation and trigger apoptosis in cervical cancer cells. Considering that hypoxia is associated with the malignant phenotypes in cervical cancer, this study aimed to uncover whether A7G exhibits suppressive effects on the hypoxia-induced malignant phenotype of cervical cancer cells (HeLa cells). Compared to normoxia, hypoxia can enhance the malignant phenotypes of HeLa cells, including cell proliferation, reduced sensitivity against chemotherapeutic agents (oxaliplatin and paclitaxel), cancer stemness, migration, and invasion. A7G intervention (20, 40, and 60 µM) could impair these malignant phenotypes of HeLa cells and upregulate the expression level of total and nuclear p16 proteins. Molecular docking analysis showed the interaction between anion exchanger 1 and A7G. In p16-silencing HeLa cells, the anticancer effects of A7G were absent. Therefore, hypoxia derives malignant phenotypes of HeLa cells, which could be impeded by A7G in a p16-dependent manner.

Identification of CREB5 as a prognostic and immunotherapeutic biomarker in glioma through multi-omics pan-cancer analysis.

BACKGROUND: The functional relevance of cyclic adenosine monophosphate (cAMP)-response element-binding protein 5 (CREB5) in cancers remains elusive, despite its significance as a member of the CREB family. The current research aims to explore the role of CREB5 in multiple cancers. METHODS: Pan-cancer analysis was performed to explore the expression patterns, prognostic value, mutational landscape as well as single-cell omic, immunologic, and drug sensitivity profiles of CREB5. Furthermore, we incorporated five distinct machine learning algorithms and determined that the least absolute shrinkage and selection operator-COX (LASSO-COX) algorithm, which exhibited the highest C index, was the optimal selection. Subsequently, we constructed a prognostic model centered around CREB5-associated genes. To elucidate the biological function of CREB5 in glioma cells, several assays including cell counting kit-8 (CCK-8), wound healing, transwell, flow cytometric were performed. RESULTS: CREB5 was overexpressed in pan-cancer and was linked to unfavorable prognosis, particularly in glioma. Furthermore, genetic alterations were determined in various types of cancer, and modifications in the CREB5 gene were linked to the prognosis. The single-cell omics and enrichment analyses showed that CREB5 was predominantly expressed in malignant glioma cells and was critically involved in the regulation of various oncogenic processes. Elevated levels of CREB5 were strongly linked with the infiltration of cancer-associated fibroblasts and the Th1 subset of CD4+ T cells. The validated CREB5-associated prognostic model reliably predicted the prognosis and drug response of glioma patients. The in vitro experiments showed that CREB5 promoted glioma cell proliferation, invasion, migration, and gap phase 2/mitotic (G2/M) phase arrest and recruited M2 macrophages into glioma cells. CONCLUSION: CREB5 has the potential to act as an oncogene and a biological marker in multiple cancers, particularly glioma.

A pan-cancer multi-omics analysis of lactylation genes associated with tumor microenvironment and cancer development.

Background: Lactylation is a significant post-translational modification bridging the gap between cancer epigenetics and metabolic reprogramming. However, the association between lactylation and prognosis, tumor microenvironment (TME), and response to drug therapy in various cancers remains unclear. Methods: First, the expression, prognostic value, and genetic and epigenetic alterations of lactylation genes were systematically explored in a pan-cancer manner. Lactylation scores were derived for each tumor using the single-sample gene set enrichment analysis (ssGSEA) algorithm. The correlation of lactylation scores with clinical features, prognosis, and TME was assessed by integrating multiple computational methods. In addition, GSE135222 data was used to assess the efficacy of lactylation scores in predicting immunotherapy outcomes. The expression of lactylation genes in breast cancers and gliomas were verified by RNA-sequencing. Results: Lactylation genes were significantly upregulated in most cancer types. CREBBP and EP300 exhibited high mutation rates in pan-cancer analysis. The prognostic impact of the lactylation score varied by tumor type, and lactylation score was a protective factor for KIRC, ACC, READ, LGG, and UVM, and a risk factor for CHOL, DLBC, LAML, and OV. In addition, a high lactylation score was associated with cold TME. The infiltration levels of CD8+ T, γδT, natural killer T cell (NKT), and NK cells were lower in tumors with higher lactylation scores. Finally, immunotherapy efficacy was worse in patients with high lactylation scores than other types. Conclusion: Lactylation genes are involved in malignancy formation. Lactylation score serves as a promising biomarker for predicting patient prognosis and immunotherapy efficacy.

BL-Hi-C reveals the 3D genome structure of Brassica crops with high sensitivity.

High-throughput Chromatin Conformation Capture (Hi-C) technologies can be used to investigate the three-dimensional genomic structure of plants. However, the practical utility of these technologies is impeded by significant background noise, hindering their capability in detecting fine 3D genomic structures. In this study, we optimized the Bridge Linker Hi-C technology (BL-Hi-C) to comprehensively investigate the 3D chromatin landscape of Brassica rapa and Brassica oleracea. The Bouquet configuration of both B. rapa and B. oleracea was elucidated through the construction of a 3D genome simulation. The optimized BL-Hi-C exhibited lower background noise compared to conventional Hi-C methods. Taking this advantage, we used BL-Hi-C to identify FLC gene loops in Arabidopsis, B. rapa, and B. oleracea. We observed that gene loops of FLC2 exhibited conservation across Arabidopsis, B. rapa, and B. oleracea. While gene loops of syntenic FLCs exhibited conservation across B. rapa and B. oleracea, variations in gene loops were evident among multiple paralogs FLCs within the same species. Collectively, our findings highlight the high sensitivity of optimized BL-Hi-C as a powerful tool for investigating the fine 3D genomic organization.

Building Feedback-Regulation System Through Atomic Design for Highly Active SO2 Sensing.

Reasonably constructing an atomic interface is pronouncedly essential for surface-related gas-sensing reaction. Herein, we present an ingenious feedback-regulation system by changing the interactional mode between single Pt atoms and adjacent S species for high-efficiency SO2 sensing. We found that the single Pt sites on the MoS2 surface can induce easier volatilization of adjacent S species to activate the whole inert S plane. Reversely, the activated S species can provide a feedback role in tailoring the antibonding-orbital electronic occupancy state of Pt atoms, thus creating a combined system involving S vacancy-assisted single Pt sites (Pt-Vs) to synergistically improve the adsorption ability of SO2 gas molecules. Furthermore, in situ Raman, ex situ X-ray photoelectron spectroscopy testing and density functional theory analysis demonstrate the intact feedback-regulation system can expand the electron transfer path from single Pt sites to whole Pt-MoS2 supports in SO2 gas atmosphere. Equipped with wireless-sensing modules, the final Pt1-MoS2-def sensors array can further realize real-time monitoring of SO2 levels and cloud-data storage for plant growth. Such a fundamental understanding of the intrinsic link between atomic interface and sensing mechanism is thus expected to broaden the rational design of highly effective gas sensors.

Creating Remarkably Moisture- and Air-Stable Macromolecular Lewis Acid by Integrating Borane within the Polymer Chain: A Highly Active Catalyst for Homo(co)polymerization of Epoxides.

Borane-based Lewis acids (LA) play an indispensable role in the Lewis pair (LP) mediated polymerization. However, most borane-based LPs are moisture- and air-sensitive. Therefore, development of moisture and air-stable borane-based LP is highly desirable. To achieve this goal, the concept of "aggregation induced enlargement effects" by chemically linking multiple borane within a nanoscopic confinement was conceived to create macromolecular LA. Accordingly, an extremely moisture and air stable macromolecular borane, namely, PVP-1B featuring poly(4-vinylphenol) backbone, was constructed. The concentration of borane active site is greatly higher than average concentration due to local confinement. Therefore, an enhanced activity was observed. Moreover, the local LA aggregation effects allow its tolerance to air and large amount of chain transfer agent. Consequently, PVP-1B showed remarkable efficiency for propylene oxide (PO) polymerization at 25 °C (TOF=27900 h-1 ). Furthermore, it enables generation of well-defined telechelic poly (CHO-alt-CO2 ) diol (0.6-15.3 kg/mol) with narrow Ds via copolymerizing cyclohexene oxide and CO2 at 80 °C. This work indicates unifying multiple borane within a polymer in a macromolecular level shows superior catalytic performance than constructing binary, bi(multi)functional systems in a molecular level. This paves a new way to make functional polyethers.

PNI, NLR and PLR combined detection prognosis of patients with chronic hepatitis C-associated cirrhosis complicated by T2DM.

INTRODUCTION: The prognostic nutrition index (PNI), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) have been studied widely in the context of cancer; however, their correlation with chronic hepatitis C-associated cirrhosis complicated by type 2 diabetes mellitus (T2DM) is unknown. AIM: To investigate the correlation of the PNI, NLR, and PLR with chronic hepatitis C-associated cirrhosis complicated by T2DM. METHODOLOGY: We investigated 226 patients, comprising 56 patients with chronic hepatitis C-associated cirrhosis complicated by T2DM mellitus (group A), 85 patients with chronic hepatitis C-associated cirrhosis (group B), and 85 patients with T2DM (group C). The baseline data of all patients were analyzed. RESULTS: A comparison of baseline data among the three groups showed significant differences in age (p = 0.008). The levels of PNI were different among the three groups (p < 0.01). The NLR, PNI, and PLR were significantly different between the good and poor prognosis groups (p < 0.05). The AUC for the combined determination of PNI, NLR, and PLR, showed excellent diagnostic performance (AUC = 0.911, 95% CI 0.741-0.985, sensitivity = 80.00 %, and specificity = 88.89%). CONCLUSIONS: The PNI, NLR, and PLR were closely related to the prognosis of chronic hepatitis C-associated cirrhosis complicated by T2DM, and their combined detection had the highest specificity and sensitivity for the early prediction of the poor prognosis of chronic hepatitis C-associated cirrhosis complicated by T2DM, which has important clinical value.

Prognostic value analysis of cholesterol and cholesterol homeostasis related genes in breast cancer by Mendelian randomization and multi-omics machine learning.

Introduction: The high incidence of breast cancer (BC) prompted us to explore more factors that might affect its occurrence, development, treatment, and also recurrence. Dysregulation of cholesterol metabolism has been widely observed in BC; however, the detailed role of how cholesterol metabolism affects chemo-sensitivity, and immune response, as well as the clinical outcome of BC is unknown. Methods: With Mendelian randomization (MR) analysis, the potential causal relationship between genetic variants of cholesterol and BC risk was assessed first. Then we analyzed 73 cholesterol homeostasis-related genes (CHGs) in BC samples and their expression patterns in the TCGA cohort with consensus clustering analysis, aiming to figure out the relationship between cholesterol homeostasis and BC prognosis. Based on the CHG analysis, we established a CAG_score used for predicting therapeutic response and overall survival (OS) of BC patients. Furthermore, a machine learning method was adopted to accurately predict the prognosis of BC patients by comparing multi-omics differences of different risk groups. Results: We observed that the alterations in plasma cholesterol appear to be correlative with the venture of BC (MR Egger, OR: 0.54, 95% CI: 0.35-0.84, p<0.006). The expression patterns of CHGs were classified into two distinct groups(C1 and C2). Notably, the C1 group exhibited a favorable prognosis characterized by a suppressed immune response and enhanced cholesterol metabolism in comparison to the C2 group. In addition, high CHG score were accompanied by high performance of tumor angiogenesis genes. Interestingly, the expression of vascular genes (CDH5, CLDN5, TIE1, JAM2, TEK) is lower in patients with high expression of CHGs, which means that these patients have poorer vascular stability. The CAG_score exhibits robust predictive capability for the immune microenvironment characteristics and prognosis of patients(AUC=0.79). It can also optimize the administration of various first-line drugs, including AKT inhibitors VIII Imatinib, Crizotinib, Saracatinib, Erlotinib, Dasatinib, Rapamycin, Roscovitine and Shikonin in BC patients. Finally, we employed machine learning techniques to construct a multi-omics prediction model(Risklight),with an area under the feature curve (AUC) of up to 0.89. Conclusion: With the help of CAG_score and Risklight, we reveal the signature of cholesterol homeostasis-related genes for angiogenesis, immune responses, and the therapeutic response in breast cancer, which contributes to precision medicine and improved prognosis of BC.

Analysis of the virulence, infection process, and extracellular enzyme activities of Aspergillus nomius against the Asian corn borer, Ostrinia furnacalis guenée (Lepidoptera: Crambidae).

The control of Ostrinia furnacalis, a major pest of maize in Xinjiang, is challenging owing to the occurrence of resistant individuals. Entomopathogenic fungi (EPF) are natural insect regulators used as substitutes for synthetic chemical insecticides. The fungus Aspergillus nomius is highly pathogenic to O. furnacalis; however, its virulence characteristics have not been identified. This study aimed to analyse the lethal efficacy, mode of infection on the cuticle, and extracellular enzyme activity of A. nomius against O. furnacalis. We found that the mortality and mycosis of O. furnacalis were dose-dependent when exposed to A. nomius and varied at different life stages. The egg-hatching and adult emergence rates decreased with an increase in conidial suspension. The highest mortality (83.33%, 7 d post-infection [DPI]) and mycosis (74.33%, 7 DPI) and the lowest mortality response (8.52 × 103 conidia mL-1) and median lethal time (4.91 d) occurred in the 3rd instar larvae of O. furnacalis. Scanning electron microscopy indicated that numerous conidia germination and infection structure formation may have contributed to the high pathogenicity of A. nomius against O. furnacalis. There were significant correlations between O. furnacalis mortality and the activities of extracellular protease, lipase, and chitinase of A. nomius. This study revealed the infection process of the highly pathogenic A. nomius against O. furnacalis, providing a theoretical basis and reference for strain improvement and field application of EPF.

A complex locus regulates highly lobed-leaf formation in Brassica juncea.

KEY MESSAGE: Lineage-specific evolution of RCO was described in Brassicaceae. BjRCO.1 and BjRCO.2 within the complex locus regulated highly lobed-leaf formation in Brassica juncea. RCO regulates the formation of lobed leaves in Brassicaceae species. RCO originated from the duplication of LMI1-type sequences and evolved through gene duplication and loss within the Brassicaceae. However, the evolutionary process and diversification of RCO in different lineages of Brassicaceae remain unclear. Although the RCO locus in B. juncea has been associated with lobed-leaf formation, its complexity has remained largely unknown. This study involved the identification of 55 LMI1-like genes in 16 species of Brassicaceae through syntenic analysis. We classified these LMI1-like genes into two types, namely LMI1-type and RCO-type, based on their phylogenetic relationship. Additionally, we proposed two independent lineage-specific evolution routes for RCO following the divergence of Aethionema. Our findings revealed that the LMI1-like loci responsible for lobed-leaf formation in Brassica species are located on the LF subgenomes. For B. juncea (T84-66V2), we discovered that the complex locus underwent duplication through segments of nucleic acid sequence containing Exostosin-LMI1-RCO (E-R-L), resulting in the tandem presence of two RCO-type and two LMI1-type genes on chromosome A10. As additional evidence, we successfully mapped the complex locus responsible for highly lobed-leaf formation to chromosome A10 using a B. juncea F2 population, which corroborated the results of our evolutionary analysis. Furthermore, through transcriptome analysis, we clarified that BjRCO.1 and BjRCO.2 within the complex locus are functional genes involved in the regulation of highly lobed-leaf formation. The findings of this study offer valuable insights into the regulation of leaf morphology for the breeding of Brassica crops.

The lack of negative association between TE load and subgenome dominance in synthesized Brassica allotetraploids.

Polyploidization is important to the evolution of plants. Subgenome dominance is a distinct phenomenon associated with most allopolyploids. A gene on the dominant subgenome tends to express to higher RNA levels in all organs as compared to the expression of its syntenic paralogue (homoeolog). The mechanism that underlies the formation of subgenome dominance remains unknown, but there is evidence for the involvement of transposon/DNA methylation density differences nearby the genes of parents as being causal. The subgenome with lower density of transposon and methylation near genes is positively associated with subgenome dominance. Here, we generated eight generations of allotetraploid progenies from the merging of parental genomes Brassica rapa and Brassica oleracea. We found that transposon/methylation density differ near genes between the parental (rapa:oleracea) existed in the wide hybrid, persisted in the neotetraploids (the synthetic Brassica napus), but these neotetraploids expressed no expected subgenome dominance. This absence of B. rapa vs. B. oleracea subgenome dominance is particularly significant because, while there is no negative relationship between transposon/methylation level and subgenome dominance in the neotetraploids, the more ancient parental subgenomes for all Brassica did show differences in transposon/methylation densities near genes and did express, in the same samples of cells, biased gene expression diagnostic of subgenome dominance. We conclude that subgenome differences in methylated transposon near genes are not sufficient to initiate the biased gene expressions defining subgenome dominance. Our result was unexpected, and we suggest a "nuclear chimera" model to explain our data.

Sildenafil Enhances the Therapeutic Effect of Islet Transplantation for Diabetic Peripheral Neuropathy via mTOR/S6K1 Pathway.

Purpose: This study aimed to investigate the potential mechanism underlying the therapeutic effect of sildenafil in combination with islet transplantation for diabetic peripheral neuropathy. Methods: A streptozotocin-induced diabetic mouse model was established to evaluate the effects of islet transplantation and sildenafil intervention. The mice were subjected to different interventions for 6 weeks, and histopathological staining and immunohistochemistry techniques were employed to examine the pathological changes and protein expressions of BDNF, MBP, and cleaved caspase-3 in the sciatic nerve tissue. Moreover, RSC96 cells were cocultured with islet cells and sildenafil under high glucose conditions to investigate the potential involvement of the mTOR/S6K1 pathway, BDNF, and MBP proteins. Western blotting was used to detect protein expression in each group. Results: The results showed that islet transplantation can restore sciatic nerve injury in diabetic mice, and sildenafil can enhance the therapeutic effect of islet transplantation. In addition, the combination of sildenafil and islet cells significantly upregulated the expression levels of mTOR/S6K1, BDNF, and MBP in RSC96 cells under high glucose conditions. Conclusions: Islet transplantation can reverse sciatic nerve injury in diabetic mice, and islet cells exhibit a protective effect on RSC96 cells under high glucose conditions via the activation of the mTOR/S6K1 pathway. Sildenafil enhances the therapeutic effect of islet transplantation, which may represent a potential treatment strategy for diabetic peripheral neuropathy.

Fabrication of Hierarchical MOF-Derived NiCo2S4@Mo-Doped Co-LDH Arrays for High-Energy-Density Asymmetric Supercapacitors.

The rational fabrication of composite structures made of mixed components has shown great potential for boosting the energy density of supercapacitors. Herein, an elaborate hierarchical MOF-derived NiCo2S4@Mo-doped Co-LDH arrays hybrid electrode was fabricated through a step-wise method. By leveraging the synergistic effects of a uniform array of NiCo2S4 nanowires as the core and an MOF-derived porous shell, the NiCo2S4@Mo-doped Co-LDH hybrid electrode demonstrates an exceptional specific capacitance of 3049.3 F g-1 at 1 A g-1. Even at a higher current density of 20 A g-1, the capacitance remains high at 2458.8 F g-1. Moreover, the electrode exhibits remarkable cycling stability, with 91% of the initial capacitance maintained after 10,000 cycles at 10 A g-1. Additionally, the as-fabricated asymmetric supercapacitor (ASC) based on the NiCo2S4@Mo-doped Co-LDH electrode achieves an impressive energy density of 97.5 Wh kg-1 at a power density of 835.6 W kg-1. These findings provide a promising approach for the development of hybrid-structured electrodes, enabling the realization of high-energy-density asymmetric supercapacitors.

The Role of G Protein-Coupled Estrogen Receptor (GPER) in Vascular Pathology and Physiology.

OBJECTIVE: Estrogen is indispensable in health and disease and mainly functions through its receptors. The protection of the cardiovascular system by estrogen and its receptors has been recognized for decades. Numerous studies with a focus on estrogen and its receptor system have been conducted to elucidate the underlying mechanism. Although nuclear estrogen receptors, including estrogen receptor-α and estrogen receptor-ß, have been shown to be classical receptors that mediate genomic effects, studies now show that GPER mainly mediates rapid signaling events as well as transcriptional regulation via binding to estrogen as a membrane receptor. With the discovery of selective synthetic ligands for GPER and the utilization of GPER knockout mice, significant progress has been made in understanding the function of GPER. In this review, the tissue and cellular localizations, endogenous and exogenous ligands, and signaling pathways of GPER are systematically summarized in diverse physiological and diseased conditions. This article further emphasizes the role of GPER in vascular pathology and physiology, focusing on the latest research progress and evidence of GPER as a promising therapeutic target in hypertension, pulmonary hypertension, and atherosclerosis. Thus, selective regulation of GPER by its agonists and antagonists have the potential to be used in clinical practice for treating such diseases.

An Optimized Protocol for Detecting Guard Cell-specific Gene Expression by in situ RT-PCR in Brassica rapa.

Since the genetic transformation of Chinese cabbage (Brassica rapa) has not been well developed, in situ RT-PCR is a valuable option for detecting guard cell-specific genes. We reported an optimized protocol of in situ RT-PCR by using a FAMA homologous gene Bra001929 in Brassica rapa. FAMA in Arabidopsis has been verified to be especially expressed in guard cells. We designed specific RT-PCR primers and optimized the protocol in terms of the (a) reverse transcription time, (b) blocking time, (c) antigen-antibody incubation time, and (d) washing temperature. Our approach provides a sensitive and effective in situ RT-PCR method that can detect low-abundance transcripts in cells by elevating their levels by RT-PCR in the guard cells in Brassica rapa.

Interploidy Introgression Shaped Adaptation during the Origin and Domestication History of Brassica napus.

Polyploidy is recurrent across the tree of life and known as an evolutionary driving force in plant diversification and crop domestication. How polyploid plants adapt to various habitats has been a fundamental question that remained largely unanswered. Brassica napus is a major crop cultivated worldwide, resulting from allopolyploidy between unknown accessions of diploid B. rapa and B. oleracea. Here, we used whole-genome resequencing data of accessions representing the majority of morphotypes and ecotypes from the species B. rapa, B. oleracea, and B. napus to investigate the role of polyploidy during domestication. To do so, we first reconstructed the phylogenetic history of B. napus, which supported the hypothesis that the emergence of B. napus derived from the hybridization of European turnip of B. rapa and wild B. oleracea. These analyses also showed that morphotypes of swede and Siberian kale (used as vegetable and fodder) were domesticated before rapeseed (oil crop). We next observed that frequent interploidy introgressions from sympatric diploids were prominent throughout the domestication history of B. napus. Introgressed genomic regions were shown to increase the overall genetic diversity and tend to be localized in regions of high recombination. We detected numerous candidate adaptive introgressed regions and found evidence that some of the genes in these regions contributed to phenotypic diversification and adaptation of different morphotypes. Overall, our results shed light on the origin and domestication of B. napus and demonstrate interploidy introgression as an important mechanism that fuels rapid diversification in polyploid species.

Development of Ogura CMS Fertility-Restored Interspecific Hybrids for Use in Cytoplasm Replacement of Golden-Heart Materials in Brassica rapa.

Ogura cytoplasmic male sterility (CMS) is one of the important methods for hybrid seed production in cruciferous crops. The lack of a restorer of fertility gene (Rfo) in Brassica rapa L. restricts the development and utilization of its germplasm resources. In this research, Brassica napus with the Rfo gene was used to restore the fertility of Ogura CMS B. rapa with the golden heart trait. Through the distant cross of two B. rapa and four B. napus, six interspecific hybrid combinations received F1 seeds. The six combinations were different in seed receiving. By morphological observation and molecular marker-assisted selection (MAS), in F1, individuals containing the Rfo gene all appeared fertile, while those without it remained male-sterile. The pollen viability of the fertile individuals was measured, and the fertile lines of the six interspecific hybrid combinations were different (40.68-80.49%). Three individuals (containing both Rfo and GOLDEN genes) with the highest pollen vitality (≥60%) were backcrossed with fertile cytoplasmic B. rapa, resulting in a total of 800 plants. Based on the MAS, a total of 144 plants with GOLDEN but no Rfo were screened (18%). Moreover, through morphological investigation, one individual with normal cytoplasm, stable fertility but without the restoring gene Rfo, the GOLDEN gene, and morphological characteristics similar to those of B. rapa was obtained. These results increased the diversity of B. rapa germplasm and provided a new method for the utilization of CMS germplasm in Brassica crops.