Long noncoding RNA SNHG9 facilitates growth of glioma stem-like cells via miR-326/SOX9 axis.

BACKGROUND: Glioma stem-like cells (GSCs) are greatly responsible for the progression of glioma. Long noncoding RNAs (lncRNAs) play an important role in glioma tumor progression. This study aims to explore the role and underlying mechanism of lncRNA SNHG9 in regulating GSC cell growth. METHODS: GSCs were obtained from glioma cells (U87 and U251) and referred to as GSC-87 and GSC-251, respectively. The interactions between miR-326 and SNHG9 or SOX9 were analyzed using luciferase reporter assay. Cell growth of GSCs was evaluated by EdU assay and sphere formation assay. RESULTS: SNHG9 expression was significantly higher in GSC-87 and GSC-251 cells than in U87 and U251 cells. SNHG9 overexpression promoted GSC cell growth, whereas SNHG9 knockdown inhibited GSC cell growth. Mechanistically, SNHG9 acted as a competitive endogenous RNA of miR-326 to elevate the expression of SOX9, a direct target of miR-326. Moreover, transfection with miR-326 inhibitor counteracted SNHG9 knockdown-mediated inhibition of GSC cell growth. CONCLUSIONS: SNHG9 facilitates growth of GSCs via the miR-326/SOX9 axis. This study provides a promising therapeutic target for glioma treatment.

Preparation of Ti3 C2 Tx MXene based solid-phase microextraction coating for sensitive determination of polychlorinated biphenyls in environmental water samples.

In this study, a new Ti3 C2 Tx -coated fiber was synthesized and utilized as coatings for solid-phase microextraction of seven polychlorinated biphenyls. The as-produced multilayered Ti3 C2 Tx MXene was characterized by X-ray diffractometer, thermos-gravimetric analysis, scanning electron microscopy, and energy dispersive spectroscopy. It is noteworthy that the Ti3 C2 Tx showed some attractive features including unique 2D layered structures, large surface area, good hydrophilicity, and rich active recognition sites, endowing it has a high affinity towards the target polychlorinated biphenyls. Subsequently, the affecting parameters on the extraction efficiency of polychlorinated biphenyls were optimized. Under the optimal conditions, a novel method for the analysis of polychlorinated biphenyls in water samples was proposed. The Ti3 C2 Tx -coated fiber-based solid-phase microextraction method showed good linearity (r2  > 0.9928), high enrichment factors (268-442), low limits of detection (0.06-0.15 ng/L), and satisfactory repeatability (RSDs < 7.5%) for the polychlorinated biphenyls. The excellent method recoveries were in the range of 90.0-98.4, 92.0-98.2, and 92.0-98.0% for river water, lake water, and tap water samples, respectively. These results suggested that the proposed Ti3 C2 Tx -coated fiber-based method represents a promising alternative for the analysis of polychlorinated biphenyls.

Identification and genetic analysis of qCL1.2, a novel allele of the "green revolution" gene SD1 from wild rice (Oryza rufipogon) that enhances plant height.

BACKGROUND: The exploitation of novel alleles from wild rice that were lost during rice cultivation could be very important for rice breeding and evolutionary studies. Plant height (PH) was a target of artificial selection during rice domestication and is still a target of modern breeding. The "green revolution" gene semi-dwarf 1 (SD1) were well documented and used in the past decades, allele from wild rice could provide new insights into the functions and evolution of this gene. RESULTS: We identified a PH-related quantitative trait locus, qCL1.2,from wild riceusing a set of chromosome segment substitution lines. qCL1.2encodesa novel allele of SD1 gene. The wild allele of SD1 is a dominant locus that can significantly promote rice internode length by regulating the expression levels of genes involved in gibberellin biosynthesis and signal transduction. Nucleotide diversity and haplotype network analyses of the SD1 gene were performed using 2822 rice landraces. Two previously reported functional nucleotide polymorphisms clearly differentiated japonica and indica rice; however, they were not associated with PH selection. Other new functional nucleotide polymorphisms in the coding, but not promoter, regions were involved in PH selection during rice domestication. Our study increasesunderstanding of the rice SD1 gene and provides additional evidence of this gene's selection during rice domestication. CONCLUSIONS: Our findings provide evidence thatSD1 gene from wild rice enhances plant height and new functional nucleotide polymorphisms of this gene were artificially selected during cultivated rice differentiation.

Development of a decaaza-cyclophane stationary phase for high-performance liquid chromatography.

A new stationary phase for high-performance liquid chromatography was prepared by covalently bonding a heteroatom-bridged cyclophane onto silica gel using 3-aminopropyltriethoxysilane as the coupling reagent. The structure of the new material was characterized by infrared spectroscopy, elemental analysis, and thermogravimetric analysis. The linear solvation energy relationship method was successfully employed to evaluate the new phase with a set of 25 solutes, and compared with octadecylsilyl and p-tert-butyl-calix[4]arene bonded stationary phases. The retention characteristics of the new phase are similar to the octadecylsilyl and conventional calixarene phases, and it also has distinctive features. In addition, the chromatographic behavior of the phase was illustrated by eluting alkylbenzenes and inorganic anions in the reversed-phase mode and anion-exchange mode, respectively. Thus, multi-interaction mechanisms and mixed-mode separation of the new phase can very likely guarantee its promising application in the analysis of complex samples. The column has been successfully employed for the analysis of triazines in milk, and it is demonstrated to be a competitive alternative analytical method for the determination of triazine herbicide residues.

Investigating the mechanism of cornel iridoid glycosides on type 2 diabetes mellitus using serum and urine metabolites in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Cornel iridoid glycosides (CIG) are extracted from Corni fructus, a herbal medicine used in traditional Chinese medicine to treat diabetes. However, the antidiabetic effects of CIG and the underlying metabolic mechanisms require further exploration. AIM OF THE STUDY: This study aimed to assess the antidiabetic effects and metabolic mechanism of CIG by performing metabolomic analyses of serum and urine samples of rats. MATERIALS AND METHODS: A rat model of type 2 diabetes mellitus (T2DM) was established by administering a low dose of streptozotocin (30 mg/kg) intraperitoneally after 4 weeks of feeding a high-fat diet. The model was evaluated based on several parameters, including fasting blood glucose (FBG), random blood glucose (RBG), urine volume, liver index, body weight, histopathological sections, and serum biochemical parameters. Subsequently, serum and urine metabolomics were analyzed using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS). Data were analyzed using unsupervised principal component analysis (PCA) and supervised orthogonal partial least squares discriminant analysis (OPLS-DA). Differential metabolites were examined by the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways to explore the underlying mechanisms. RESULTS: After 4 weeks of treatment with different doses of CIG, varying degrees of antidiabetic effects were observed, along with reduced liver and pancreatic injury, and improved oxidative stress levels. Compared with the T2DM group, 19 and 23 differential metabolites were detected in the serum and urine of the CIG treatment group, respectively. The key metabolites involved in pathway regulation include taurine, chenodeoxycholic acid, glycocholic acid, and L-tyrosine in the serum and glycine, hippuric acid, phenylacetylglycine, citric acid, and D-glucuronic acid in the urine, which are related to lipid, amino acid, energy, and carbohydrate metabolism. CONCLUSIONS: This study confirmed the antidiabetic effects of CIG and revealed that CIG effectively controlled metabolic disorders in T2DM rats. This seems to be meaningful for the clinical application of CIG, and can benefit further studies on CIG mechanism.

Experience of multi-disciplinary treatment of multiple cerebellar diffuse large B-cell lymphoma: A case report.

RATIONALE: Primary central nervous system lymphoma (PCNSL) is a rare, highly malignant form of non-Hodgkin lymphoma categorized under the diffuse large B-cell type. It accounts for merely 1% of all non-Hodgkin lymphoma cases and comprises approximately 3% of all brain tumors. The involvement of the cerebellum is observed in only 9% of these cases. Recently, we came across an unusual instance: a young man presenting with multiple lesions located specifically within the cerebellum. PATIENT CONCERNS: A 26-year-old male was admitted to the hospital due to severe headaches. He has a medical history of sporadic headaches, accompanied by dizziness, nausea, and vomiting persisting for a month. Over the last 10 days, his headaches have intensified, coupled with decreased vision and protrusion of the eyeballs. Magnetic resonance imaging (MRI) revealed abnormal signals in both cerebellar hemispheres. DIAGNOSES, INTERVENTIONS, AND OUTCOMES: Diagnostic procedures included cerebellar biopsy, posterior fossa decompression, and lateral ventricle drainage. Histopathological examination identified diffuse large B-cell lymphoma (DLBCL) with high proliferative activity. To minimize neurotoxicity, chemotherapy involved intrathecal methotrexate (MTX) injections combined with the CHOP program. The patient has shown good tolerance to the treatment so far. LESSONS: While the definitive optimal treatment approach remains elusive, current chemotherapy centered on high-dose MTX stands as the standard induction therapy. Integrating surgery with radiotherapy and chemotherapy significantly extends patient survival.

Characterization and identification of chemical constituents in Corni Fructus and effect of storage using UHPLC-LTQ-Orbitrap-MS.

Corni Fructus (CF) has been widely used as both traditional medicine and food; however, systematic studies on its chemical profile and the impact of storage periods on the indicative components are lacking. In this study, UHPLC-LTQ-Orbitrap-MS was used to investigate the fragmentation behaviors of multiple compounds from CF and the content variety of its indicative components for different storage periods. The major basic components of CF were determined to be iridoid glucosides, pentacyclic triterpenoids, phenolic acids, tannins and flavonoids. The characteristic cleavage pathways of the iridoid glucosides, pentacyclic triterpenoids, phenolic acids, tannins and flavonoids were further investigated and elaborated, which could assist in identifying the structures of similar components of other Chinese herbal medicines. Using accurate mass measurements for each precursor ion and the subsequent fragmented ions, and then comparing with standards and literature data, a total of 130 components, including 69 iridoid glucosides, 9 pentacyclic triterpenoids, 16 phenolic acids, 20 tannins and 16 flavonoids, 47 of which are potentially new compounds, were identified. The storage period studies indicated that the contents of 19 indicative components in CF changed differently with the prolongation of the storage period. Among them, morroniside, loganin, sweroside, cornuside, gallic acid, oleanolic acid and ursolic acid were the most important. These results provide abundant information for the identification and improved understanding of the chemical constituents in CF to clarify the content variety of its indicative components for different storage periods.

Prognostic value of PD-L1 and Siglec-15 expression in patients with nasopharyngeal carcinoma.

Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) might be involved in the activation of important pathways related to tumor immune escape, along with programmed death-ligand 1 (PD-L1). Here, we aimed to investigate the correlation between the expression of Siglec-15 and PD-L1 in nasopharyngeal carcinoma (NPC) patients. We determined the expression of PD-L1 via immunohistochemical staining and that of Siglec-15 via immunofluorescence staining in 182 NPC tissue samples. A significant correlation was identified between the PD-L1 and Siglec-15 expression (P = 0.000). Moreover, Kaplan-Meier survival curves showed that PD-L1 expression was associated with improved overall survival (OS) (P = 0.025) and Siglec-15 expression was associated with improved distant failure-free survival (D-FFS) (P = 0.048). Moreover, multivariate Cox analysis showed that PD-L1 and Siglec-15 were independent predictors of OS (P = 0.020) and D-FFS (P = 0.047), respectively. The results of the log-rank test and Cox regression analyses showed that patients exhibiting no PD-L1/Siglec-15 expression had significant advantages regarding OS, compared to other groups (P = 0.037). PD-L1 and Siglec-15 may represent novel biomarkers for predicting the prognosis of NPC patients. Siglec-15 may be considered as a potential target for the development of therapeutics for NPC treatment in the future.

Injectable hydrogel loaded with paclitaxel and epirubicin to prevent postoperative recurrence and metastasis of breast cancer.

Post-operative recurrence and metastasis is a major challenge for breast cancer treatment. Local chemotherapy is a promising strategy that can overcome this problem. In this study, we synthesized an injectable hyaluronic acid (HA)-based hydrogel loaded with paclitaxel (PTX) nanoparticles and epirubicin (EPB) (PPNPs/EPB@HA-Gel). PPNPs/EPB@HA-Gel steadily released the encapsulated drugs to achieve long-term inhibition of tumor recurrence and metastasis in a murine post-operative breast tumor model, which prolonged their survival without any systemic toxicity. The drug-loaded hydrogel inhibited the proliferation and migration of tumor cells in vitro, and significantly increased tumor cell apoptosis in vivo. Therefore, PPNPs/EPB@HA-Gel can be used as a local chemotherapeutic agent to prevent postoperative recurrence and metastasis of breast cancer.

High-Quality Genomes and High-Density Genetic Map Facilitate the Identification of Genes From a Weedy Rice.

Genes have been lost or weakened from cultivated rice during rice domestication and breeding. Weedy rice (Oryza sativa f. spontanea) is usually recognized as the progeny between cultivated rice and wild rice and is also known to harbor an gene pool for rice breeding. Therefore, identifying genes from weedy rice germplasms is an important way to break the bottleneck of rice breeding. To discover genes from weedy rice germplasms, we constructed a genetic map based on w-hole-genome sequencing of a F2 population derived from the cross between LM8 and a cultivated rice variety. We further identified 31 QTLs associated with 12 important agronomic traits and revealed that ORUFILM03g000095 gene may play an important role in grain length regulation and participate in grain formation. To clarify the genomic characteristics from weedy rice germplasms of LM8, we generated a high-quality genome assembly using single-molecule sequencing, Bionano optical mapping, and Hi-C technologies. The genome harbored a total size of 375.8 Mb, a scaffold N50 of 24.1 Mb, and originated approximately 0.32 million years ago (Mya) and was more closely related to Oryza sativa ssp. japonica. and contained 672 unique genes. It is related to the formation of grain shape, heading date and tillering. This study generated a high-quality reference genome of weedy rice and high-density genetic map that would benefit the analysis of genome evolution for related species and suggested an effective way to identify genes related to important agronomic traits for further rice breeding.

Corrigendum: Low-Dose Total Body Irradiation Can Enhance Systemic Immune Related Response Induced by Hypo-Fractionated Radiation.

[This corrects the article DOI: 10.3389/fimmu.2019.00317.].

Cr2O3/cellulose hybrid nanocomposites with unique properties: Facile synthesis, photocatalytic, bactericidal and antioxidant application.

Development of high responsive photocatalysts for the degradation of dye from water is a significance method to solve the difficulties of water contamination. In the present project, Cr2O3 nanoparticles were decorated onto cellulose through a facile synthesis method, which was exposed to characterization by XRD, FESEM, DLS, PL, and UV-vis spectroscopy. The structural attributes confirmed the presence of rhombohedral phase of Cr2O3 nanoparticles. The mean crystal size of Cr2O3, and Cr2O3/cellulose nanocomposites were 38.50 nm, and 50.11 nm, respectively. The band gap values (Eg) of Cr2O3, and Cr2O3/cellulose nanocomposites were was found 3.00, and 2.53 eV, respectively. Moreover, the morphological and optical studies have been showed the impressive photocatalytic properties of the prepared Cr2O3/cellulose nanocomposites. The photocatalytic efficiency of Cr2O3, and Cr2O3/cellulose nanocomposites has been investigated for the photo-degradation of crystal violet in the ultraviolet light region. The Cr2O3/cellulose indicated promising photocatalytic performance and up to 99.65% of the crystal violet was photo-degraded in 40 min. The obtained crystal violet degradation results were fitted onto a Langmuir-Hinshelwood (L-H) plot. The antioxidant performances of Cr2O3, and Cr2O3/cellulose were analyzed. The beneficial antibacterial performance of the Cr2O3/cellulose nanocomposites was tested by various bacteria as Escherichia coli, Pseudomonas aeruginosa, staphylococcus aurous, and Streptococcus pyogenes.

A Combination of Long-Day Suppressor Genes Contributes to the Northward Expansion of Rice.

Growing cultivated rice with a moderate heading date is the key to expanding its cultivation area and maintaining stable yields. The genes that regulate heading date are largely cloned; however, it remains unclear how genetic mutations and their combinations affect the heading date and adaptability of cultivated rice. Here, we report the analysis of genetic variation in eight long-day flowering suppressor genes (Hd1, DTH8, Ghd7, OsCOL4, DTH7, Hd6, Se5, and PhyB) and the phylogenetic relationship of eight genes. Genetic variations in DTH8, Ghd7, Hd1, DTH7, PhyB, and OsCOL4 are correlated with differences in heading date and the correlation between the genetic diversity of Hd6 and Se5 and rice heading data are weak. One group of haplotypes of DTH8, Ghd7, Hd1, DTH7, PhyB, and OsCOL4 are associated with earlier heading dates and appear to have accumulated during the northward expansion of rice cultivation. A minimum of four group A alleles of DTH8, Ghd7, Hd1, DTH7, PhyB, and OsCOL4 are required for the growth of cultivated rice at latitudes above 30°N. This study presents a preliminary investigation of the genetic patterns and adaptation mechanisms of long-day flowering suppressor genes and provides a useful reference for the molecular breeding of rice cultivars for various environments and farming systems.

Low-Dose Total Body Irradiation Can Enhance Systemic Immune Related Response Induced by Hypo-Fractionated Radiation.

A systemic immune related response (SIME) of radiotherapy has been occasionally observed on metastatic tumors, but the clinical outcomes remain poor. Novel treatment approaches are therefore needed to improve SIME ratio. We used a combination of hypo-fractionated radiation therapy (H-RT) with low-dose total body irradiation (L-TBI) in a syngeneic mouse model of breast and colon carcinoma. The combination therapy of H-RT and L-TBI potentially enhanced SIME by infiltration of CD8+ T cell and altering the immunosuppressive microenvironment in non-irradiated subcutaneous tumor lesions. The frequency of IFN-γ, as a tumor-specific CD8+ T cells producing, significantly inhibited the secondary tumor growth of breast and colon. Our findings suggest that L-TBI could serve as a potential therapeutic agent for metastatic breast and colon cancer and, together with H-RT, their therapeutic potential is enhanced significantly.

When West Meets East: The Origins and Spread of Weedy Rice Between Continental and Island Southeast Asia.

Weedy crop relatives are among the world's most problematic agricultural weeds, and their ability to rapidly evolve can be enhanced by gene flow from both domesticated crop varieties and wild crop progenitor species. In this study, we examined the role of modern commercial crop cultivars, traditional landraces, and wild relatives in the recent emergence and proliferation of weedy rice in East Malaysia on the island of Borneo. This region of Malaysia is separated from the Asian continent by the South China Sea, and weedy rice has become a major problem there more recently than on the Malaysian peninsular mainland. Using 24 polymorphic SSR loci and genotype data from the awn-length domestication gene An-1, we assessed the genetic diversity, population structure and potential origins of East Malaysian weeds; 564 weedy, cultivated and wild rice accessions were analyzed from samples collected in East Malaysia, Peninsular Malaysia and neighboring countries. While there is considerable evidence for contributions of Peninsular Malaysian weed ecotypes to East Malaysian populations, we find that local crop cultivars and/or landraces from neighboring countries are also likely contributors to the weedy rice infestations. These findings highlight the implications of genetic admixture from different cultivar source populations in the spread of weedy crop relatives and the urgent need for preventive measurements to maintain sustainable crop yields.

Prognostic value of TIGAR and LC3B protein expression in nasopharyngeal carcinoma.

PURPOSE: Autophagy, the process responsible for degrading cytoplasmic organelles to sustain cellular metabolism, has been associated with cancer initiation and progression. As TP53-induced glycolysis and apoptosis regulator (TIGAR) is among the important genes that can regulate autophagy, we aimed to investigate the correlation between the expression levels of TIGAR and the autophagy-related protein microtubule-associated protein 1 light chain 3 (LC3B), as well as their association with clinical outcomes, in nasopharyngeal carcinoma (NPC) patients. METHODS: We detected the expressions of TIGAR and LC3B in 182 NPC tissue samples via immunohistochemical staining. RESULTS: A significant correlation between TIGAR and LC3B expressions was identified (P=0.045). Moreover, survival analysis showed that TIGAR- or LC3B+ expression was associated with improved overall survival, local regional failure-free survival, distant failure-free survival, and failure-free survival rates, compared with TIGAR+ or LC3B- expression, respectively. Meanwhile, when combining TIGAR with LC3B expression in terms of prognostic value, patients with TIGAR+/LC3B- expression were significantly disadvantaged with regard to overall survival, local regional failure-free survival, distant failure-free survival, and failure-free survival compared with other groups based on the log-rank test and Cox regression analyses (all P<0.05). CONCLUSION: TIGAR and LC3B may be novel biomarkers for predicting the prognosis of NPC patients and could be utilized as potential targets for future therapeutics aimed at treating NPC patients.

[Studies of the possible mechanisms for protective effects of recombinant human growth hormone on intestinal mucosa barrier in rat sepsis].

OBJECTIVE: To investigate the protective effects of recombinant human growth hormone (rhGH) on intestinal mucosal barrier in rat sepsis and explore its possible mechanisms. METHODS: E. coli was injected intraperitoneally to produce rats sepsis models. Forty-two female SD rats were randomly divided into the control group (group C), sepsis group (group S) and treatment group (group T). Group S and group T were further divided into 1 d and 3 d subgroups (T1d,T3d, Sld, S3d), respectively. The expression of IGF-1 mRNA in liver, expression of Bcl-2 protein in intestine, bacteria translocation, the levels of growth hormone(GH) and insulin-like growth factor-1 (IGF-1) in plasma, and the histological appearance of intestine were determined dynamically by means of RT-PCR, radioimmunoassay, immunohistochemical staining and other corresponding methods, respectively. RESULTS: (1) rhGH could significantly attenuate intestinal mucosal injuries and ameliorate bacteria translocation on sepsis rats. (2) The levels of Bcl-2 protein expression in intestine in group T (T1d:2441 +/- 117; T3d: 3628 +/- 235) were obviously higher than those of group S (S1d: 321 +/- 36; S3d: 1873 +/- 57) (P < 0.01). (3) The plasma levels of GH in group T (T1d: 1.28 +/- 0.24 microg/L; T3d: 2.14 +/- 0.48 microg/L) increased markedly than those of group S (S1d: 0.74 -/+ 0.12 microg/L; S3d: 0.60 +/- 0.18 microg/L) (P < 0.01). (4) The plasma levels of IGF-1 in group T (Tld: 168.94 +/- 65.67 microg/L; T3d: 201.56 +/- 64.98 microg/L) elevated significantly than those of group S (Sld: 116.72 +/- 13.96 microg/L; S3d:107.50 +/- 23.53 microg/L) (P < 0.05). (5) The levels of liver IGF-1 mRNA in group T (Tld: 0.98 +/- 0.20; T3d: 1.76 +/- 0.17) were significantly higher than those in group S (S1d: 0.38 +/- 0.09; S3d: 0.46 +/- 0.10) (P < 0.01). CONCLUSION: rhGH conferred protective efficacy in maintaining the integrity of intestinal mucosal barrier against sepsis in rat. The possible mechanisms might involve the rhGH-diminished apoptosis of intestinal mucosa cells and the rhGH-maintained intestinal mucosa barrier via the roles of GH and IGF-1.

Calixarene ionic liquid modified silica gel: A novel stationary phase for mixed-mode chromatography.

A novel calixarene ionic liquid functionalized silica material was synthesized by the preparation of a new calixarene monomer and its grafting on mercaptopropyl modified silica gel. The material was characterized by infrared spectra, elemental analysis, and thermogravimetric analysis. To explore the retention mechanism of the stationary phase, linear solvation energy relationships (LSER) equation as an effective mathematical model was used. In addition to this, the distinct separation mechanisms were outlined by selected examples of chromatographic separations in the different modes. In reversed-phase liquid chromatography, this new stationary phase presented specific chromatographic performance when evaluated using alkylbenzenes, PAHs and phenols as solutes. Due to the existing polar functional groups, this stationary phase can also be used in hydrophilic interaction chromatography, six nucleosides and four ginsenosides were separated successfully in hydrophilic mode. Furthermore, anions can be separated on the column in anion exchange mode. Thus, this new material was can be applied as a new kind of mixed-mode stationary phase in liquid chromatography, which allows an exceptionally flexible adjustment of retention and selectivity by tuning the experimental conditions.

Little White Lies: Pericarp Color Provides Insights into the Origins and Evolution of Southeast Asian Weedy Rice.

Weedy rice is a conspecific form of cultivated rice (Oryza sativa L.) that infests rice fields and results in severe crop losses. Weed strains in different world regions appear to have originated multiple times from different domesticated and/or wild rice progenitors. In the case of Malaysian weedy rice, a multiple-origin model has been proposed based on neutral markers and analyses of domestication genes for hull color and seed shattering. Here, we examined variation in pericarp (bran) color and its molecular basis to address how this trait evolved in Malaysian weeds and its possible role in weed adaptation. Functional alleles of the Rc gene confer proanthocyanidin pigmentation of the pericarp, a trait found in most wild and weedy Oryzas and associated with seed dormancy; nonfunctional rc alleles were strongly favored during rice domestication, and most cultivated varieties have nonpigmented pericarps. Phenotypic characterizations of 52 Malaysian weeds revealed that most strains are characterized by the pigmented pericarp; however, some weeds have white pericarps, suggesting close relationships to cultivated rice. Phylogenetic analyses indicate that the Rc haplotypes present in Malaysian weeds likely have at least three distinct origins: wild O. rufipogon, white-pericarp cultivated rice, and red-pericarp cultivated rice. These diverse origins contribute to high Rc nucleotide diversity in the Malaysian weeds. Comparison of Rc allelic distributions with other rice domestication genes suggests that functional Rc alleles may confer particular fitness benefits in weedy rice populations, for example, by conferring seed dormancy. This may promote functional Rc introgression from local wild Oryza populations.