Plasma metabolites as mediators in immune cell-pancreatic cancer risk: insights from Mendelian randomization.

Background: Immune cells play a crucial role in the development and progression of pancreatic cancer, yet the causal relationship remains uncertain due to complex immune microenvironments and conflicting research findings. Mendelian randomization (MR), this study aims to delineate the causal relationships between immune cells and pancreatic cancer while identifying intermediary factors. Methods: The genome-wide association study (GWAS) data on immune cells, pancreatic cancer, and plasma metabolites are derived from public databases. In this investigation, inverse variance weighting (IVW) as the primary analytical approach to investigate the causal relationship between exposure and outcome. Furthermore, this study incorporates MR-Egger, simple mode, weighted median, and weighted mode as supplementary analytical approaches. To ensure the reliability of our findings, we further assessed horizontal pleiotropy and heterogeneity and evaluated the stability of MR results using the Leave-one-out method. In conclusion, this study employed mediation analysis to elucidate the potential mediating effects of plasma metabolites. Results: Our investigation revealed a causal relationship between immune cells and pancreatic cancer, highlighting the pivotal roles of CD11c+ monocytes (odds ratio, ORIVW=1.105; 95% confidence interval, 95%CI: 1.002-1.218; P=0.045), HLA DR+ CD4+ antigen-presenting cells (ORIVW=0.920; 95%CI: 0.873-0.968; P=0.001), and HLA DR+ CD8br T cells (ORIVW=1.058; 95%CI: 1.002-1.117; P=0.041) in pancreatic cancer progression. Further mediation analysis indicated that oxalate (proportion of mediation effect in total effect: -11.6%, 95% CI: -89.7%, 66.6%) and the mannose to trans-4-hydroxyproline ratio (-19.4, 95% CI: -136%, 96.8%) partially mediate the relationship between HLA DR+ CD8br T cells and pancreatic cancer in nature. In addition, our analysis indicates that adrenate (-8.39%, 95% CI: -18.3%, 1.54%) plays a partial mediating role in the association between CD11c+ monocyte and pancreatic cancer, while cortisone (-26.6%, 95% CI: 138%, -84.8%) acts as a partial mediator between HLA DR+ CD4+ AC and pancreatic cancer. Conclusion: This MR investigation provides evidence supporting the causal relationship between immune cell and pancreatic cancer, with plasma metabolites serving as mediators. Identifying immune cell phenotypes with potential causal effects on pancreatic cancer sheds light on its underlying mechanisms and suggests novel therapeutic targets.

Progress of single-cell RNA sequencing combined with spatial transcriptomics in tumour microenvironment and treatment of pancreatic cancer.

In recent years, single-cell analyses have revealed the heterogeneity of the tumour microenvironment (TME) at the genomic, transcriptomic, and proteomic levels, further improving our understanding of the mechanisms of tumour development. Single-cell RNA sequencing (scRNA-seq) technology allow analysis of the transcriptome at the single-cell level and have unprecedented potential for exploration of the characteristics involved in tumour development and progression. These techniques allow analysis of transcript sequences at higher resolution, thereby increasing our understanding of the diversity of cells found in the tumour microenvironment and how these cells interact in complex tumour tissue. Although scRNA-seq has emerged as an important tool for studying the tumour microenvironment in recent years, it cannot be used to analyse spatial information for cells. In this regard, spatial transcriptomics (ST) approaches allow researchers to understand the functions of individual cells in complex multicellular organisms by understanding their physical location in tissue sections. In particular, in related research on tumour heterogeneity, ST is an excellent complementary approach to scRNA-seq, constituting a new method for further exploration of tumour heterogeneity, and this approach can also provide unprecedented insight into the development of treatments for pancreatic cancer (PC). In this review, based on the methods of scRNA-seq and ST analyses, research progress on the tumour microenvironment and treatment of pancreatic cancer is further explained.

SlCRCa is a key D-class gene controlling ovule fate determination in tomato.

Cell fate determination and primordium initiation on the placental surface are two key events for ovule formation in seed plants, which directly affect ovule density and seed yield. Despite ovules form in the marginal meristematic tissues of the carpels, angiosperm carpels evolved after the ovules. It is not clear how the development of the ovules and carpels is coordinated in angiosperms. In this study, we identify the S. lycopersicum CRABS CLAW (CRC) homologue SlCRCa as an essential determinant of ovule fate. We find that SlCRCa is not only expressed in the placental surface and ovule primordia but also functions as a D-class gene to block carpel fate and promote ovule fate in the placental surface. Loss of function of SlCRCa causes homeotic transformation of the ovules to carpels. In addition, we find low levels of the S. lycopersicum AINTEGUMENTA (ANT) homologue (SlANT2) favour the ovule initiation, whereas high levels of SlANT2 promote placental carpelization. SlCRCa forms heterodimer with tomato INNER NO OUTER (INO) and AGAMOUS (AG) orthologues, SlINO and TOMATO AGAMOUS1 (TAG1), to repress SlANT2 expression during the ovule initiation. Our study confirms that angiosperm basal ovule cells indeed retain certain carpel properties and provides mechanistic insights into the ovule initiation.

Single-cell RNA sequencing reveals immune cell dysfunction in the peripheral blood of patients with highly aggressive gastric cancer.

Highly aggressive gastric cancer (HAGC) is a gastric cancer characterized by bone marrow metastasis and disseminated intravascular coagulation (DIC). Information about the disease is limited. Here we employed single-cell RNA sequencing to investigate peripheral blood mononuclear cells (PBMCs), aiming to unravel the immune response of patients toward HAGC. PBMCs from seven HAGC patients, six normal advanced gastric cancer (NAGC) patients, and five healthy individuals were analysed by single-cell RNA sequencing. The expression of genes of interest was validated by bulk RNA-sequencing and ELISA. We found a massive expansion of neutrophils in PBMCs of HAGC. These neutrophils are activated, but immature. Besides, mononuclear phagocytes exhibited an M2-like signature and T cells were suppressed and reduced in number. Analysis of cell-cell crosstalk revealed that several signalling pathways involved in neutrophil to T-cell suppression including APP-CD74, MIF-(CD74+CXCR2), and MIF-(CD74+CD44) pathways were increased in HAGC. NETosis-associated genes S100A8 and S100A9 as well as VEGF, PDGF, FGF, and NOTCH signalling that contribute to DIC development were upregulated in HAGC too. This study reveals significant changes in the distribution and interactions of the PBMC subsets and provides valuable insight into the immune response in patients with HAGC. S100A8 and S100A9 are highly expressed in HAGC neutrophils, suggesting their potential to be used as novel diagnostic and therapeutic targets for HAGC.

Heat stress impairs floral meristem termination and fruit development by affecting the BR-SlCRCa cascade in tomato.

Floral meristem termination is a key step leading to carpel initiation and fruit development. The frequent occurrence of heat stress due to global warming often disrupts floral determinacy, resulting in defective fruit formation. However, the detailed mechanism behind this phenomenon is largely unknown. Here, we identify CRABS CLAW a (SlCRCa) as a key regulator of floral meristem termination in tomato. SlCRCa functions as an indispensable floral meristem terminator by suppressing SlWUS activity through the TOMATO AGAMOUS 1 (TAG1)-KNUCKLES (SlKNU)-INHIBITOR OF MERISTEM ACTIVITY (SlIMA) network. A direct binding assay revealed that SlCRCa specifically binds to the promoter and second intron of WUSCHEL (SlWUS). We also demonstrate that SlCRCa expression depends on brassinosteroid homeostasis in the floral meristem, which is repressed by heat stress via the circadian factor EARLY FLOWERING 3 (SlELF3). These results provide new insights into floral meristem termination and the heat stress response in flowers and fruits of tomato and suggest that SlCRCa provides a platform for multiple protein interactions that may epigenetically abrogate stem cell activity at the transition from floral meristem to carpel initiation.

Auxin homeostasis is maintained by sly-miR167-SlARF8A/B-SlGH3.4 feedback module in the development of locular and placental tissues of tomato fruits.

The locular gel, produced by the placenta, is important for fruit flavor and seed development in tomato. However, the mechanism underlying locule and placenta development is not fully understood yet. Here, we show that two SlARF transcription factors, SlARF8B and SlARF8A (SlARF8A/B), promote the development of locular and placenta tissues. The expression of both SlARF8A and SlARF8B is repressed by sly-microRNA167 (sly-miR167), allowing for the activation of auxin downstream genes. In slarf8a, slarf8b, and slarf8a/b mutants, the auxin (IAA) levels are decreased, whereas the levels of inactive IAA conjugates including IAA-Ala, IAA-Asp, and IAA-Glu are increased. We further find that SlARF8B directly inhibits the expression of SlGH3.4, an acyl acid amino synthetase that conjugates the amino acids to IAA. Disruption of such auxin balance by the increased expression of SlGH3.4 or SlGH3.2 results in defective locular and placental tissues. Taken together, our findings reveal an important regulatory module constituted by sly-miR167-SlARF8A/B-SlGH3.4 during the development of locular and placenta tissues of tomato fruits.

Dissecting the immune discrepancies in mouse liver allograft tolerance and heart/kidney allograft rejection.

The liver is the most tolerogenic of transplanted organs. However, the mechanisms underlying liver transplant tolerance are not well understood. The comparison between liver transplantation tolerance and heart/kidney transplantation rejection will deepen our understanding of tolerance and rejection in solid organs. Here, we built a mouse model of liver, heart and kidney allograft and performed single-cell RNA sequencing of 66,393 cells to describe the cell composition and immune cell interactions at the early stage of tolerance or rejection. We also performed bulk RNA-seq of mouse liver allografts from Day 7 to Day 60 post-transplantation to map the dynamic transcriptional variation in spontaneous tolerance. The transcriptome of lymphocytes and myeloid cells were characterized and compared in three types of organ allografts. Cell-cell interaction networks reveal the coordinated function of Kupffer cells, macrophages and their associated metabolic processes, including insulin receptor signalling and oxidative phosphorylation in tolerance induction. Cd11b+ dendritic cells (DCs) in liver allografts were found to inhibit cytotoxic T cells by secreting anti-inflammatory cytokines such as Il10. In summary, we profiled single-cell transcriptome analysis of mouse solid organ allografts. We characterized the immune microenvironment of mouse organ allografts in the acute rejection state (heart, kidney) and tolerance state (liver).

Advancement of single-cell sequencing for clinical diagnosis and treatment of pancreatic cancer.

Single-cell sequencing is a high-throughput technique that enables detection of genomic, transcriptomic, and epigenomic information at the individual cell level, offering significant advantages in detecting cellular heterogeneity, precise cell classification, and identifying rare subpopulations. The technique holds tremendous potential in improving the diagnosis and treatment of pancreatic cancer. Moreover, single-cell sequencing provides unique insights into the mechanisms of pancreatic cancer metastasis and cachexia, paving the way for developing novel preventive strategies. Overall, single-cell sequencing has immense potential in promoting early diagnosis, guiding personalized treatment, and preventing complications of pancreatic cancer. Emerging single-cell sequencing technologies will undoubtedly enhance our understanding of the complex biology of pancreatic cancer and pave the way for new directions in its clinical diagnosis and treatment.

Mycoplasma infection mimicking a malignancy in a waldenstrom macroglobulinemia patient.

BACKGROUND: Mycoplasma hominis infection is common in urinary tract. 18F-FDG-PET/CT is a valuable tool for tumor and infection diagnosis. Few studies have shown the 18F-FDG-PET/CT images after mycoplasma infection. CASE PRESENTATION: Here we described a case of Waldenstrom macroglobulinemia with thickened bladder wall. The 18F-FDG-PET/CT showed the SUVmax up to 36.1 mimicking bladder cancer. The results of histopathological examination and metagenomic sequencing of the blood and urinary revealed the Mycoplasma hominis infection. CONCLUSION: The full consideration should be given to the possibility of infection besides tumor in lesions with high SUV value in 18F-FDG-PET/CT, especially in immunodeficiency patients.

Association between Family Environment and Adolescents' Sexual Adaptability: Based on the Latent Profile Analysis of Personality Traits.

Sexual adaptation plays an important role in psychosexual health. Our study aimed to investigate the relationship between the family environment and sexual adaptability among adolescents with different personality traits. A cross-sectional study was conducted in Shanghai and Shanxi province. A total of 1106 participants aged 14-19 was surveyed in 2019, including 519 boys and 587 girls. Univariate analyses and mixed regression models were performed to assess the association. Girls had a significantly lower average score of sexual self-adaptation compared to boys (4.01 ± 0.77 vs. 4.32 ± 0.64, p < 0.001). We found that the family environment did not impact boys' sexual adaptation in different personality groups. For girls in a balanced group, expressiveness factors improved their sexual adaptability (p < 0.05), intellectual-cultural orientation and organization promoted social adaptability (p < 0.05) and active-recreational orientation and control decreased their social adaptability (p < 0.05). In the high-neuroticism group, cohesion facilitated sexual control (p < 0.05), while conflict and organization reduced sexual control ability, and active-recreational orientation decreased sexual adaptation (p < 0.05). No factors associated with the family environment were found to influence sexual adaptability in groups with low neuroticism and high ratings in other personality factors. Compared with boys, girls demonstrated lower sexual self-adaptability, and their overall sexual adaptability was more susceptible to the family environment.

Synthesis of Silver Nanowires Using a Polyvinylpyrrolidone-Free Method with an Alpinia zerumbet Leaf Based on the Oriented Attachment Mechanism.

In this study, silver nanowires (AgNWs) were successfully synthesized by using a polyvinylpyrrolidone (PVP)-free hydrothermal method with an Alpinia zerumbet leaf chunk as a reducing agent and template. Meanwhile, the mechanism of biomass synthesis of AgNWs is also explored. The AgNWs have a diameter of ∼77 nm and a length of ∼10 µm. During the hydrothermal process, the biomass initially serves as a reducing agent to reduce silver ions. As the reaction proceeds, the biomass will form a pipe-shaped soft template by hydrothermal carbonization. Silver ions are adsorbed and reduced along the pipe-shaped soft templates to form silver nanorods, and adjacent nanorods are merged to AgNWs. Thus, AgNWs are grown along the pipeline soft template based on the oriented attachment mechanism. Inspired by this, the mechanism of the polyol method was further investigated. In the initial growth stage, AgNWs synthesized by the polyol method have a V-shaped notch. Therefore, AgNWs synthesized by the polyol method may also grow on the basis of the oriented attachment mechanism with PVP as a template.

Cold stress induces malformed tomato fruits by breaking the feedback loops of stem cell regulation in floral meristem.

Fruit malformation is a major constrain in fruit production worldwide resulting in substantial economic losses. The farmers for decades noticed that the chilling temperature before blooming often caused malformed fruits. However, the molecular mechanism underlying this phenomenon is unclear. Here we examined the fruit development in response to cold stress in tomato, and demonstrated that short-term cold stress increased the callose accumulation in both shoot apical and floral meristems, resulting in the symplastic isolation and altered intercellular movement of WUS. In contrast to the rapidly restored SlWUS transcription during the recovery from cold stress, the callose removal was delayed due to obstructed plasmodesmata. The delayed reinstatement of cell-to-cell transport of SlWUS prevented the activation of SlCLV3 and TAG1, causing the interrupted feedback inhibition of SlWUS expression, leading to the expanded stem cell population and malformed fruits. We further showed that the callose dynamics in response to short-term cold stress presumably exploits the mechanism of bud dormancy during the seasonal growth, involving two antagonistic hormones, abscisic acid and gibberellin. Our results provide a novel insight into the cold stress regulated malformation of fruit.

Quantitative analysis of s-PB/SBR blend dispersion morphology using computer image processing-assisted Raman spectroscopic techniques.

In the materials industry, it is significant to clarify the correlation between the material dispersion morphology and the mechanical properties of rubber blends, which are comprehensively employed and are always in the spotlight. However, there are no generalized automatic visual characterization methods for dispersion morphology at present. In this paper, we wish to introduce a novel computer image processing-assisted approach for quantitative evaluation based on Raman mapping images, in which inhomogeneity factor Kc was defined to characterize the homogeneity of rubber blends. This numerical processing technique will provide a more objective standard for the quality control of relevant materials and products. It may be of profound impact on the information and automation of material engineering and is a key technique for automatic production and quality inspection of the related materials in industry.

The Key Gene Expression Patterns and Prognostic Factors in Malignant Transformation from Enchondroma to Chondrosarcoma.

Enchondroma (EC) is a common benign bone tumor. It has the risk of malignant transformation to Chondrosarcoma (CS). However, the underlying mechanism is unclear. The gene expression profile of EC and CS was obtained from Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified using GEO2R. We conducted the enrichment analysis and constructed the gene interaction network using the DEGs. We found that the epithelial-mesenchymal transition (EMT) and the VEGFA-VEGF2R signaling pathway were more active in CS. The CD8+ T cell immunity was enhanced in CS I. We believed that four genes (MFAP2, GOLM1, STMN1, and HN1) were poor predictors of prognosis, while two genes (CAB39L and GAB2) indicated a good prognosis. We have revealed the mechanism in the tumor progression and identified the key genes that predicted the prognosis. This study provided new ideas for the diagnosis and treatment of EC and CS.

Cold starting temperature time-related compensation model of inertial sensors based on particle swarm optimization algorithm.

With the miniaturization of inertial instruments, sensors mounted inside are vulnerable to interference. In a complex thermal transmission environment, temperature drift is the main factor restricting the precision of high-performance inertial sensors. To solve this problem, a new method for compensating the time-related cold starting temperature drift of the inertial sensors is introduced in this paper. Based on the perspective that temperature drift can be regarded as the response curve of the sensor system to temperature and temperature gradient, temperature compensation models of first-order, second-order, and higher-order are proposed. Meanwhile, the particle swarm optimization algorithm is used to solve the model parameters. Under various practical circumstances, the method can be used to flexibly compensate the temperature drift and reduce the standard deviation of the output signal by about four times. Compared to other models or algorithms, the simulation and experimental results indicate that the proposed model is superior in adaptability, stability, and reliability.

Inflammation-related genes S100s, RNASE3, and CYBB and risk of leukemic transformation in patients with myelodysplastic syndrome with myelofibrosis.

Myelodysplastic syndrome with myelofibrosis (MDS-MF) has been associated with an inferior prognosis compared with MDS without MF. However, MDS-MF is not listed independently as a subtype of MDS, and its clinical and genetic characteristics remain poorly understood. We retrospectively compared 53 patients with MDS-MF (44 MF grade 1/MF1; 9 MF grade 2-3/MF2 - 3) and 31 with de novo MDS without MF (MDS). The leukemic transformation risks of both MDS-MF2 - 3 and MDS-MF1 were increased compared with the MDS group. To identify the potential mechanisms responsible for the leukemic transformation of MDS-MF, we performed single-cell sequencing for one MDS-MF2 - 3 patient before and after leukemic transformation to explore the variations in gene expression levels. In addition to upgraded expression levels of acute myeloid leukemia-related genes during leukemic transformation, expression levels of some inflammation-related genes (such as S100s, RNASE3, and CYBB) were also increased, and inflammation-related pathways were up-regulated. These results suggest that inflammation-related genes and pathways may play an important role in the leukemic transformation of MDS-MF.

The modified endoscopic retrograde appendicitis therapy versus antibiotic therapy alone for acute uncomplicated appendicitis in children.

BACKGROUND: Endoscopic retrograde appendicitis therapy (ERAT) is an emerging endoscopic treatment modality for acute uncomplicated appendicitis (AUA) supported by several case series. However, to date, systematic studies have not been conducted in children and the prospective comparative data are lacking. Moreover, due to a concern for future malignancy risk in children from ionizing radiation, we used contrast-enhanced ultrasound (CEUS) instead of endoscopic retrograde appendiceal radiography (ERAR). Therefore, we conducted a prospective, randomized control clinical trial to compare the modified ERAT (mERAT) to antibiotic therapy in children with AUA. The aim of this study was to evaluate the safety and feasibility and of mERAT in the treatment of hospitalized children with AUA. METHODS: Children with AUA, confirmed by ultrasonography and or abdominal computed tomography, were consecutively enrolled from October 2018 to February, 2020. They were randomly assigned to receive mERAT or routine antibiotic treatment. Patients were followed until May, 2020. Th primary outcome variable was the duration of relief of the abdominal pain after treatment. We collected patient's demographics, ultrasonic imaging findings, colonoscopy findings, and treatment outcomes of the mERAT and adverse even associated with mERAT. RESULTS: A total of 83 children were enrolled. 36 were randomized to mERAT and 47 to antibiotics treatment. All children in the mERAT group had endoscopic confirmed acute uncomplicated appendicitis, and there were no significant complications. However, 9 of patients in antibiotic group were poor responsive to treatment and switched to mERAT. The overall success rate of treatment with mERAT (100%) was significantly higher than that of antibiotics (80.9%) (P = 0.004). The median time to discharge was significantly shorter in mERAT group than in antibiotics treatment group [6.0 ± 1.76 days] (P = 0.004). CONCLUSIONS: mERAT provide a new alternative therapeutic option for childhood with AUA, especially for families who are reluctant to undergo an appendectomy.

AUREA maintains the balance between chlorophyll synthesis and adventitious root formation in tomato.

Flooding tolerance is an important trait for tomato breeding. In this study, we obtained a recessive mutant exhibiting highly enhanced submergence resistance. Phenotypical analyses showed that this resistant to flooding (rf) mutant displays slightly chlorotic leaves and spontaneous initiation of adventitious roots (ARs) on stems. The mutation was mapped to the phytochromobilin synthase gene AUREA (AU), in which a single amino acid substitution from asparagine to tyrosine occurred. In addition to the classic function of AU in phytochrome and chlorophyll biogenesis in leaves, we uncovered its novel role in mediating AR formation on stems. We further observed temporal coincidence of the two phenotypes in the rf mutant: chlorosis and spontaneous AR formation and revealed that AU functions by maintaining heme homeostasis. Interestingly, our grafting results suggest that heme might play roles in AR initiation via long-distance transport from leaves to stems. Our results present genetic evidence for the involvement of the AU-heme oxygenase-1-heme pathway in AR initiation in tomato. As fruit production and yield in the rf mutant are minimally impacted, the mutation identified in this study may provide a target for biotechnological renovation of tomato germplasm in future breeding.

A single-cell survey of cellular hierarchy in acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a fatal hematopoietic malignancy and has a prognosis that varies with its genetic complexity. However, there has been no appropriate integrative analysis on the hierarchy of different AML subtypes. METHODS: Using Microwell-seq, a high-throughput single-cell mRNA sequencing platform, we analyzed the cellular hierarchy of bone marrow samples from 40 patients and 3 healthy donors. We also used single-cell single-molecule real-time (SMRT) sequencing to investigate the clonal heterogeneity of AML cells. RESULTS: From the integrative analysis of 191727 AML cells, we established a single-cell AML landscape and identified an AML progenitor cell cluster with novel AML markers. Patients with ribosomal protein high progenitor cells had a low remission rate. We deduced two types of AML with diverse clinical outcomes. We traced mitochondrial mutations in the AML landscape by combining Microwell-seq with SMRT sequencing. We propose the existence of a phenotypic "cancer attractor" that might help to define a common phenotype for AML progenitor cells. Finally, we explored the potential drug targets by making comparisons between the AML landscape and the Human Cell Landscape. CONCLUSIONS: We identified a key AML progenitor cell cluster. A high ribosomal protein gene level indicates the poor prognosis. We deduced two types of AML and explored the potential drug targets. Our results suggest the existence of a cancer attractor.

The novel gene BrMYB2, located on chromosome A07, with a short intron 1 controls the purple-head trait of Chinese cabbage (Brassica rapa L.).

Anthocyanins are important secondary metabolites in plants, but information on anthocyanin biosynthesis mechanisms in Chinese cabbage is limited. The new purple head Chinese cabbage cultivar 11S91 was analyzed, and an R2R3-MYB regulatory gene BrMYB2, located on chromosome A07, controlling the dominant purple-head trait was isolated. High expression of BrMYB2 generated a large accumulation of anthocyanins in 11S91, accompanied by highly upregulated BrTT8, BrF3'H, BrDFR1, BrANS1, BrUGTs, BrATs, and BrGSTs. 11S91 inherited the purple locus from purple trait donor 95T2-5, and they shared consensus CDSs and gDNAs with those of BrMYB2 (cBrMYB2 and gBrMYB2). Two SNPs in cBrMYB2 in 11S91 did not cause loss of function; in addition to several SNPs at both ends of intron 1, a large deletion had occurred in intron 1 of gBrMYB2 in 11S91. Genetic transformation of Arabidopsis showed that gBrMYB2 overexpression lines presented deeper purple color and higher expression than did the cBrMYB2 and cBrmyb2 lines, whereas gBrmyb2 with a long intron 1 did not cause the purple phenotype. We first show that BrMYB2 promotes anthocyanin biosynthesis under the control of the short intron 1 of gBrMYB2 in purple head Chinese cabbage, and gBrmyb2 with a long intron 1 represses anthocyanin production in white head Chinese cabbage. This evidence provides a new understanding of anthocyanin biosynthesis and purple germplasm generation in Brassica vegetables.