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BACKGROUND: Allergic rhinitis (AR) is a prevalent allergic disease, which seriously affects the sufferers' life quality and increases the socioeconomic burden. Guominkang (GMK), a well-known prescription for AR treatment, showed satisfactory effects; while its anti-allergic components remain to be disclosed. AlGaN/GaN HEMT biochip is more sensitive and cost-effective than other binding equipments, indicating its great potential for screening of active ingredients from herbal medicines. METHODS: AR mouse models were first established to test the anti-allergic effect of GMK and discover the ingredients absorbed into blood by ultra-high performance liquid chromatography-mass spectra (UHPLC-MS). Then, novel Syk/Lyn/Fyn-functionalized high electron mobility transistor (HEMT) biochips with high sensitivity and specificity were constructed and applied to screen the active components. Finally, the results from HEMT biochips screening were validated via in silico (molecular docking and molecular dynamics simulation), in vitro (RBL-2H3 cells), and in vivo (PCA mice model) assays. RESULTS: GMK showed a potent therapeutic effect on AR mice, and fifteen components were identified from the medicated plasma. Furthermore, hamaudol was firstly found to selectively inhibit the Syk and Lyn, and emodin was to selectively inhibit Lyn, which were further confirmed by isothermal titration calorimetry, molecular docking, and molecular dynamics simulation analyses. Suppression of the activation of FcεRI-MAPK signals might be the possible mechanism of the anti-allergic effect of hamaudol. CONCLUSIONS: The targets of emodin and hamaudol were discovered by HEMT biochips for the first time. This study provided a novel and effective strategy to discover active components in a complex herbal formula by using AlGaN/GaN HEMT biochips.
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Antialérgicos , Emodina , Rinitis Alérgica , Ratones , Animales , Antialérgicos/farmacología , Simulación del Acoplamiento Molecular , Emodina/farmacología , Rinitis Alérgica/tratamiento farmacológico , Modelos Animales de EnfermedadRESUMEN
Centromeres consist of highly repetitive sequences that are challenging to map, clone, and sequence. Active genes exist in centromeric regions, but their biological functions are difficult to explore owing to extreme suppression of recombination in these regions. In this study, we used the CRISPR/Cas9 system to knock out the transcribed gene Mitochondrial Ribosomal Protein L15 (OsMRPL15), located in the centromeric region of rice (Oryza sativa) chromosome 8, resulting in gametophyte sterility. Osmrpl15 pollen was completely sterile, with abnormalities appearing at the tricellular stage including the absence of starch granules and disrupted mitochondrial structure. Loss of OsMRPL15 caused abnormal accumulation of mitoribosomal proteins and large subunit rRNA in pollen mitochondria. Moreover, the biosynthesis of several proteins in mitochondria was defective, and expression of mitochondrial genes was upregulated at the mRNA level. Osmrpl15 pollen contained smaller amounts of intermediates related to starch metabolism than wild-type pollen, while biosynthesis of several amino acids was upregulated, possibly to compensate for defective mitochondrial protein biosynthesis and initiate consumption of carbohydrates necessary for starch biosynthesis. These results provide further insight into how defects in mitoribosome development cause gametophyte male sterility.
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Oryza , Oryza/genética , Oryza/metabolismo , Mitocondrias/genética , Mitocondrias/metabolismo , Genes de Plantas , Almidón/metabolismo , Polen/genética , Polen/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
Guominkang (GMK), a Chinese medicine formula, has been used to treat allergic diseases in clinical settings for many years. To evaluate the antiallergic effect and molecular mechanism of action of GMK extract, RBL-2H3 cell models and passive cutaneous anaphylaxis (PCA) mouse models were established. High performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) analyses were performed to characterize the chemical composition of GMK. A total of 94 compounds were identified or tentatively identified from GMK. Three of them, emodin, ursolic acid, and hamaudol, were identified for the first time as potential active compounds in GMK, since they inhibited the degranulation of mast cells. The anti-allergic effect of hamaudol was the first to be discovered. GMK could markedly mitigate the shade of Evans Blue extravasation and ear incrassation in PCA mouse models. Additionally, GMK significantly inhibited the degranulation of mast cells, suppressed mast cell degranulation by reducing Ca2+ influx and the levels of TNF-α, IL-4, and histamine, and markedly inhibited the phosphorylation of Lyn, Syk, PLCγ1, IκBα, and NF-κB p65. Molecular docking results indicated that hamaudol and emodin had strong interaction with FcÉRI and NF-κB related proteins, while ursolic acid only interacted with NF-κB associated proteins. These results suggest GMK suppresses the activation of MCs both in vivo and in vitro. The underlying mechanism of its anti-allergic activity is associated with the inhibition of FcÉRI and NF-κB activation.
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Antialérgicos , Emodina , Ratones , Animales , Antialérgicos/farmacología , Antialérgicos/uso terapéutico , Inmunoglobulina E , FN-kappa B/genética , FN-kappa B/metabolismo , Anafilaxis Cutánea Pasiva , Mastocitos/metabolismo , Emodina/metabolismo , Simulación del Acoplamiento Molecular , Ácido UrsólicoRESUMEN
OBJECTIVE: To verify the efficacy of electroacupuncture (EA) on classical trigeminal neuralgia (CTN), and to observe the brain functional status of patients with CTN and the intervention effects of EA on brain function by resting-state functional magnetic resonance imaging (rs-fMRI). METHODS AND ANALYSIS: Thirty CTN patients will be randomly divided into EA combined with carbamazepine group and carbamazepine group in 2:1 ratio by using a random number table. Patients in EA combined with carbamazepine will receive EA treatment and carbamazepine for four weeks. The carbamazepine group will only receive carbamazepine treatment. VAS (visual analogue scale), HAMA (Hamilton Anxiety Scale), HAMD (Hamilton Depression Scale) and SF-36 (short form 36 health survey) will be performed before, after four-week treatments and at three-month follow-up in CTN patients. Six CTN patients will be randomly selected from EA combined with carbamazepine group and carbamazepine group, respectively, before treatment, and twelve paired healthy participants will be recruited at the same time. The twelve CTN patients will be scanned by rs-fMRI before and after treatment, and the healthy participants will be scanned by rs-fMRI only at baseline. Regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF) analysis will be carried out to compare the dysfunctional brain regions between CTN patients and healthy participants, as well as the differences between two groups of patients with CTN after treatment. TRIAL REGISTRATION: ChiCTR-1900027873.
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To explore a new underlying molecular mechanism of Huangkui Extract Powder (HKEP) in the alleviation of diabetic nephropathy (DN). Murine immortalized podocytes were divided into (i) normal glucose (NG, 5.6 mM), (ii) NG + HKEP (0.45 g/L), (iii) HG, and (iv) HG + HKEP (0.45 g/L) groups. MTT assay and flow cytometry were used to detect the podocyte proliferation, apoptosis and cell cycle. Cell viability was inhibited, and apoptosis increased in(iii) HG group compared with (i) NG group (p<0.05). mRNA and protein expression of nephrin and podocin significantly decreased in (iii) HG group compared with (i) NG group (p<0.05). When compared with (iii) HG group, (iv) HG + HKEP group had higher cell viability, lower apoptotic rate and higher mRNA and protein expression of nephrin and podocin (p<0.05). HKEP can attenuate HG-induced podocyte damage, which may be one of the mechanisms of HKEP for attenuating DN.
Explorar un nuevo mecanismo molecular subyacente del extracto del polvo de Huangkui (HKEP) en el alivio de la nefropatía diabética (ND). Los podocitos murinos inmortalizados se dividieron en (i) grupos de glucosa normal (NG, 5,6 mM), (ii) NG + HKEP (0,45 g/L), (iii) HG y (iv) HG + HKEP (0,45 g/L). Se utilizaron el ensayo MTT y la citometría de flujo para detectar la proliferación de podocitos, la apoptosis y el ciclo celular. La viabilidad celular se inhibió y la apoptosis aumentó en el grupo (iii) HG en comparación con el grupo (i) NG (p<0,05). La expresión de ARNm y proteínas de nefrina y podocina disminuyó significativamente en el grupo (iii) HG en comparación con el grupo (i) NG (p<0,05). En comparación con el grupo (iii) HG, el grupo (iv) HG + HKEP tuvo una mayor viabilidad celular, una tasa de apoptosis más baja y una expresión de ARNm y proteínas más altas de nefrina y podocina (p<0,05). HKEP puede atenuar el daño de los podocitos inducido por HG, que puede ser uno de los mecanismos de HKEP para atenuar la DN.
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Extractos Vegetales/administración & dosificación , Nefropatías Diabéticas/tratamiento farmacológico , Podocitos/efectos de los fármacos , Polvos , Extractos Vegetales/genética , Ciclo Celular , Western Blotting , Apoptosis/efectos de los fármacos , Técnicas de Cultivo de Célula , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , GlucosaRESUMEN
Speech processing relies on interactions between auditory and motor systems and is asymmetrically organized in the human brain. The left auditory system is specialized for processing of phonemes, whereas the right is specialized for processing of pitch changes in speech affecting prosody. In speakers of tonal languages, however, processing of pitch (i.e., tone) changes that alter word meaning is left-lateralized indicating that linguistic function and language experience shape speech processing asymmetries. Here, we investigated the asymmetry of motor contributions to auditory speech processing in male and female speakers of tonal and non-tonal languages. We temporarily disrupted the right or left speech motor cortex using transcranial magnetic stimulation (TMS) and measured the impact of these disruptions on auditory discrimination (mismatch negativity; MMN) responses to phoneme and tone changes in sequences of syllables using electroencephalography (EEG). We found that the effect of motor disruptions on processing of tone changes differed between language groups: disruption of the right speech motor cortex suppressed responses to tone changes in non-tonal language speakers, whereas disruption of the left speech motor cortex suppressed responses to tone changes in tonal language speakers. In non-tonal language speakers, the effects of disruption of left speech motor cortex on responses to tone changes were inconclusive. For phoneme changes, disruption of left but not right speech motor cortex suppressed responses in both language groups. We conclude that the contributions of the right and left speech motor cortex to auditory speech processing are determined by the functional roles of acoustic cues in the listener's native language.SIGNIFICANCE STATEMENT The principles underlying hemispheric asymmetries of auditory speech processing remain debated. The asymmetry of processing of speech sounds is affected by low-level acoustic cues, but also by their linguistic function. By combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG), we investigated the asymmetry of motor contributions to auditory speech processing in tonal and non-tonal language speakers. We provide causal evidence that the functional role of the acoustic cues in the listener's native language affects the asymmetry of motor influences on auditory speech discrimination ability [indexed by mismatch negativity (MMN) responses]. Lateralized top-down motor influences can affect asymmetry of speech processing in the auditory system.
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Estimulación Acústica/métodos , Percepción Auditiva/fisiología , Lenguaje , Corteza Motora/fisiología , Percepción del Habla/fisiología , Estimulación Magnética Transcraneal/métodos , Adolescente , Adulto , Electroencefalografía/métodos , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: The tuber of Pinellia ternata has been used for a thousand years in China. P. ternata possessed the activities of anti-emetic, sedative-hypnotic, anti-cancer, anti-asthmatic, anti-tussive, and anti-inflammatory. It is the representative of expectorant medicines in Traditional Chinese Medicine (TCM). Phlegm is the pathological product and a new pathogenic factor of the metabolite, which is analogous to the damage of oxidative stress. PURPOSE: The objectives of the study were to investigate the protective activity and mechanism of ethanol extract of P. ternata tubers (PTE) and its main constituents on oxidative stress-induced cell senescence. METHODS: H2O2 and AAPH were used to establish cellular senescence models. The anti-aging effects of PTE and its components were evaluated by SA-ß-gal staining, flow cytometry, scanning electron microscope (SEM), and multiple microplate reader, the molecular mechanisms of them were investigated by qRT-PCR and Western Blot. RESULTS: We found PTE exhibited the apparent effect on cell senescence, evidenced by inhibiting senescence ß-Galactosidase (SA-ß-gal) expression, lipofuscin accumulation, cell cycle arrest at the G2/M phase, oxidative damage and apoptosis, and increasing telomerase activity. Their mechanisms were related to increase expressions of SIRT1, forkhead box 3a (Foxo3a), Bcl-2, active regulator of SIRT1, RPS19BP1 (AROS), and Hu antigen R (HuR), but decrease Bax, p53 and deleted in breast cancer 1 (DBC1) levels. Furthermore, adenosine, and succinic acid, as the critical substances in PTE, could also inhibit SA-ß-gal expression and cell cycle arrest, down-regulate the expression of Bax, and up-regulate Bcl-2, SirT1, and Foxo3a. CONCLUSIONS: We have demonstrated that PTE slows down oxidative stress-induced cell senescence, and adenosine and succinic acid are the key active components.
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Estrés Oxidativo/efectos de los fármacos , Pinellia/química , Extractos Vegetales/farmacología , Animales , Senescencia Celular/efectos de los fármacos , Chlorocebus aethiops , Regulación hacia Abajo/efectos de los fármacos , Medicamentos Herbarios Chinos/química , Etanol/química , Humanos , Peróxido de Hidrógeno/farmacología , Lipofuscina/metabolismo , Células PC12 , Extractos Vegetales/química , Tubérculos de la Planta/química , Sustancias Protectoras/química , Sustancias Protectoras/farmacología , Proteínas/genética , Proteínas/metabolismo , Ratas , Telomerasa/metabolismo , Células Vero , beta-Galactosidasa/metabolismoRESUMEN
Highly coordinated pollen wall patterning is essential for male reproductive development. Here, we report the identification of Defective Microspore Development 1 (DMD1), which encodes a nuclear-localized protein possessing transactivation activity. DMD1 is preferentially expressed in the tapetum and microspores during post-meiotic development. Mutations in DMD1 cause a male-sterile phenotype with impaired microspore cell integrity. The mutants display abnormal callose degradation, accompanied by inhibited primexine thickening in the newly released microspores. Several genes associated with callose degradation and primexine formation are downregulated in dmd1 anthers. In addition, irregular Ubisch body morphology and discontinuous endexine occur, and the baculum is completely absent in dmd1. DMD1 interacts with Tapetum Degeneration Retardation (TDR), a basic helix-loop-helix transcription factor required for exine formation. Taken together, our results suggest that DMD1 is responsible for microspore cell integrity, primexine formation and exine pattern formation during Oryza sativa (rice) microspore development.
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Oryza/metabolismo , Proteínas de Plantas/fisiología , Polen/metabolismo , Apoptosis , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Microscopía Electrónica de Transmisión , Oryza/crecimiento & desarrollo , Infertilidad Vegetal , Proteínas de Plantas/metabolismo , Polen/crecimiento & desarrollo , Polen/ultraestructuraRESUMEN
Response regulators play significant roles in controlling various biological processes; however, their roles in plant meiosis remain unclear. Here, we report the identification of OsRR24/LEPTOTENE1 (LEPTO1), a rice (Oryza sativa) type-B response regulator that participates in the establishment of key molecular and morphological features of chromosomes in leptotene, an early stage of prophase I in meiosis. Although meiosis initiates normally, as indicated by staining of the centromere-specific histone CENH3, the meiotic chromosomes in lepto1 mutant pollen mother cells fail to form the thin thread-like structures that are typical of leptotene chromosomes in wild-type pollen mother cells. Furthermore, lepto1 mutants fail to form chromosomal double-strand breaks, do not recruit meiosis-specific proteins to the meiotic chromosomes, and show disrupted callose deposition. LEPTO1 also is essential for programmed cell death in tapetal cells. LEPTO1 contains a conserved signal receiver domain (DDK) and a myb-like DNA binding domain at the N terminus. LEPTO1 interacts with two authentic histidine phosphotransfer (AHP) proteins, OsAHP1 and OsAHP2, via the DDK domain, and a phosphomimetic mutation of the DDK domain relieves its repression of LEPTO1 transactivation activity. Collectively, our results show that OsRR24/LEPTO1 plays a significant role in the leptotene phase of meiotic prophase I.
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Proteínas de Ciclo Celular/metabolismo , Meiosis/genética , Proteínas Nucleares/metabolismo , Oryza/genética , Proteínas de Ciclo Celular/genética , Cromosomas de las Plantas/genética , Meiosis/fisiología , Profase Meiótica I/genética , Profase Meiótica I/fisiología , Proteínas Nucleares/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/genética , Polen/metabolismoRESUMEN
Meiotic cytokinesis influences the fertility and ploidy of gametes. However, limited information is available on the genetic control of meiotic cytokinesis in plants. Here, we identified a rice mutant with low male fertility, defective callose in meiosis 1 (dcm1). The pollen grains of dcm1 are proved to be defective in exine formation. Meiotic cytokinesis is disrupted in dcm1, resulting in disordered spindle orientation during meiosis II and formation of pollen grains with varied size and DNA content. We demonstrated that meiotic cytokinesis defect in dcm1 is caused by prematurely dissolution of callosic plates. Furthermore, peripheral callose surrounding the dcm1 pollen mother cells (PMCs) also disappeared untimely around pachytene. The DCM1 protein contains five tandem CCCH motifs and interacts with nuclear poly (A) binding proteins (PABNs) in nuclear speckles. The expression profiles of genes related to callose synthesis and degradation are significantly modified in dcm1. Together, we propose that DCM1 plays an essential role in male meiotic cytokinesis by preserving callose from prematurely dissolution in rice.
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Glucanos/metabolismo , Oryza/citología , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Núcleo Celular/metabolismo , Citocinesis/genética , Citocinesis/fisiología , Técnicas de Inactivación de Genes , Genes de Plantas , Meiosis/genética , Meiosis/fisiología , Oryza/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Polen/citología , Polen/genética , Polen/metabolismo , Proteínas de Unión a Poli(A)/metabolismo , Homología de Secuencia de Aminoácido , Secuencias Repetidas en Tándem , Dedos de Zinc/genéticaRESUMEN
In angiosperms, the key step in sexual reproduction is successful acquisition of meiotic fate. However, the molecular mechanism determining meiotic fate remains largely unknown. Here, we report that OsSPOROCYTELESS (OsSPL) is critical for meiotic entry in rice (Oryza sativa). We performed a large-scale genetic screen of rice sterile mutants aimed to identify genes regulating meiotic entry and identified OsSPL using map-based cloning. We showed that meiosis-specific callose deposition, chromatin organization, and centromere-specific histone H3 loading were altered in the cells corresponding to pollen mother cells in Osspl anthers. Global transcriptome analysis showed that the enriched differentially expressed genes in Osspl were mainly related to redox status, meiotic process, and parietal cell development. OsSPL might form homodimers and interact with TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factor OsTCP5 via the SPL dimerization and TCP interaction domain. OsSPL also interacts with TPL (TOPLESS) corepressors, OsTPL2 and OsTPL3, via the EAR motif. Our results suggest that the OsSPL-mediated signaling pathway plays a crucial role in rice meiotic entry, which appears to be a conserved regulatory mechanism for meiotic fate acquisition in angiosperms.
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Meiosis , Oryza/citología , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Arabidopsis/metabolismo , Diferenciación Celular/genética , Gametogénesis en la Planta/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Mitosis/genética , Modelos Biológicos , Mutación/genética , Proteínas Nucleares/metabolismo , Oryza/genética , Oxidación-Reducción , Filogenia , Proteínas de Plantas/genética , Polen/citología , Polen/metabolismo , Unión Proteica , Multimerización de Proteína , Transcripción GenéticaRESUMEN
INTRODUCTION: Apigenin, a natural flavone, is widely distributed in plants such as celery, parsley and chamomile. It is present principally as glycosylated in nature. Higher intake of apigenin could reduce the risk of chronic diseases. It has gained particular interest in recent years as a beneficial, health-promoting agent with low intrinsic toxicity. Areas covered: This review summarizes and the absorption, distribution, metabolism and excretion (ADME) properties of apigenin, and drug-drug interaction of apigenin. Expert opinion: Since apigenin is a bioactive plant flavone and is widely distributed in common food, its consumption through the diet is recommended. Apigenin-enriched drugs are better for some chronic diseases, but may affect animal and human health if present in the daily diet. Dietary or therapeutic apigenin has value as a good cellular regulator in cancer, especially cancers of the gastrointestinal tract. Due to apigenin's limitations on absorption and bioavailability, novel carriers would need to be developed to enhance the oral bioavailability of apigenin. Further research about its ADME properties and drug-drug interactions are needed before apigenin can be brought to clinical trials.
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Apigenina/farmacocinética , Interacciones Farmacológicas , Extractos Vegetales/farmacocinética , Animales , Disponibilidad Biológica , Interacciones de Hierba-Droga , HumanosRESUMEN
As a traditional Chinese medicine,pheretima is widely used for thousands of years in China. According to the studies in recent years,the pharmacological effects and clinical researches of pheretima were summarized based on the introduction of chemical constituents, which could provide information for the further study.
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The formation of diverse, appropriately patterned cell types is critical in the development of all complex multicellular organisms. In flowering plants, anther patterning is a complex process essential for successful sexual reproduction. However, few genes regulating this process have been characterized to date. We report here that the gene MICROSPORELESS2 (MIL2) regulates early anther cell differentiation in rice (Oryza sativa). The anthers of mil2 mutants were characterized using molecular markers and cytological examination. The MIL2 gene was cloned and its expression pattern was analyzed through RNA in situ hybridization. The localization of the MIL2 protein was observed by immunostaining. MIL2 encodes the rice homolog of the Arabidopsis TAPETUM DETERMINANT1 (TPD1) protein. However, mil2 anthers display phenotypes different from those of tpd1 mutants, with only two layers of anther wall cells formed. MIL2 has an expression pattern distinct from that of TPD1. Its transcripts and proteins predominate in inner parietal cells, but show little accumulation in reproductive cells. Our results demonstrate that MIL2 is responsible for the differentiation of primary parietal cells into secondary parietal cells in rice anthers, and suggest that rice and Arabidopsis anthers might share similar regulators in anther patterning, but divergent mechanisms are employed in these processes.
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Diferenciación Celular , Flores/citología , Flores/metabolismo , Oryza/citología , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Flores/genética , Flores/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas/genética , Datos de Secuencia Molecular , Mutación/genética , Oryza/genética , Fenotipo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Polen/citología , Polen/metabolismo , Homología de Secuencia de Ácido NucleicoRESUMEN
In budding yeast, the ZMM complex is closely associated with class I crossovers and synaptonemal complex (SC) formation. However, the relationship between the ZMM genes remains unclear in most higher eukaryotes. Here, we identify the rice ZIP4 homolog, a member of the ZMM gene group, and explore its relationship with two other characterized ZMM genes, MER3 and ZEP1. Our results show that in the rice zip4 mutant, the chiasma frequency is greatly reduced, although synapsis proceeds with only mild defects. Immunocytological analyses of wild-type rice reveal that ZIP4 presents as punctuate foci and colocalizes with MER3 in prophase I meiocytes. Additionally, ZIP4 is essential for the loading of MER3 onto chromosomes, but not vice versa. Double-mutant analyses show that zip4 mer3 displays a greater decrease in the mean number of chiasmata than either of the zip4 or mer3 single mutants, suggesting that ZIP4 and MER3 work cooperatively to promote CO formation but their individual contributions are not completely identical in rice. Although zep1 alone gives an increased chiasma number, both zip4 zep1 and mer3 zep1 show a much lower chiasma number than the zip4 or mer3 single mutants. These results imply that the normal functions of ZIP4 and MER3 are required for the regulation of COs by ZEP1.
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Emparejamiento Cromosómico/genética , Cromosomas de las Plantas/genética , Intercambio Genético , Meiosis/genética , Oryza/citología , Oryza/genética , Proteínas de Plantas/metabolismo , Clonación Molecular , Genes de Plantas/genética , Genotipo , Modelos Biológicos , Mutación/genética , Fenotipo , Infertilidad Vegetal/genética , Proteínas de Plantas/genética , Polen/citología , Polen/metabolismo , Transporte de ProteínasRESUMEN
The switch from mitosis to meiosis is one of the most pivotal events in eukaryotes undergoing sexual reproduction. However, the mechanisms orchestrating meiosis initiation remain elusive, particularly in plants. Flowering plants are heterosporous, with male and female spore genesis adopting different developmental courses. We show here that plant pollen mother cells contain a specific meiosis initiation machinery through characterization of a rice (Oryza sativa) gene, MICROSPORELESS1 (MIL1). The mil1 mutant does not produce microspores in anthers but has the normal female fertility. Detailed molecular and cytological investigations demonstrate that mil1 anthers are defective in the meiotic entry of sporogenous cell progenies and in the differentiation of surrounding somatic cell layers, resulting in locules filled with somatic cells instead of microspores. Furthermore, analysis of mil1 msp1 double mutants reveals that due to the absence of MIL1, the cells in their anther locule center do not activate meiotic cell cycle either, generating a similar anther phenotype to mil1. MIL1 encodes a plant-specific CC-type glutaredoxin, which could interact with TGA transcription factors. These results suggest meiotic entry in microsporocytes is directed by an anther-specific mechanism, which requires MIL1 activity, and redox regulation might play important roles in this process.
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Flores/crecimiento & desarrollo , Glutarredoxinas/metabolismo , Meiosis , Oryza/genética , Proteínas de Plantas/metabolismo , Polen/citología , Clonación Molecular , Flores/citología , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Prueba de Complementación Genética , Glutarredoxinas/genética , Datos de Secuencia Molecular , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Filogenia , Proteínas de Plantas/genética , Polen/crecimiento & desarrollo , Factores de Transcripción/metabolismoRESUMEN
The events occurring at the onset of meiosis have not been fully elucidated. In the present study, OsAM1 was identified in rice (Oryza sativa L.) by map-based cloning. OsAM1, a homolog of Arabidopsis SWI1 and maize AM1, encodes a protein with a coiled-coil domain in its central region. In the Osam1 mutant, pollen mother cells are arrested at leptotene, showing that OsAM1 is required for the leptotene-zygotene transition. Immunocytological analysis revealed that OsAM1 exists as foci in early prophase I meiocytes. Very faint OsREC8 foci persisted in the Osam1 mutant, indicating that OsAM1 is not required for the initial meiotic recruitment of OsREC8. In the absence of OsAM1, many other critical meiotic components, including PAIR2, ZEP1 and OsMER3, could not be correctly installed onto chromosomes. In contrast, in pair2, Osmer3 and zep1 mutants, OsAM1 could be loaded normally, suggesting that OsAM1 plays a fundamental role in building the proper chromosome structure at the beginning of meiosis.
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Proteínas de Ciclo Celular/metabolismo , Profase Meiótica I , Oryza/citología , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Ciclo Celular/genética , Emparejamiento Cromosómico/genética , Expresión Génica , Mutación , Oryza/genética , Proteínas de Plantas/genética , Polen/embriología , Polen/genética , Reacción en Cadena de la Polimerasa , ARN Interferente Pequeño , Alineación de Secuencia , Complejo Sinaptonémico/metabolismoRESUMEN
During meiosis, the paired homologous chromosomes are tightly held together by the synaptonemal complex (SC). This complex consists of two parallel axial/lateral elements (AEs/LEs) and one central element. Here, we observed that PAIR3 localized to the chromosome core during prophase I and associated with both unsynapsed AEs and synapsed LEs. Analyses of the severe pair3 mutant demonstrated that PAIR3 was essential for bouquet formation, homologous pairing and normal recombination, and SC assembly. In addition, we showed that although PAIR3 was not required for the initial recruitment of PAIR2, it was required for the proper association of PAIR2 with chromosomes. Dual immunostaining revealed that PAIR3 highly colocalized with REC8. Moreover, studies using a rec8 mutant indicated that PAIR3 localized to chromosomes in a REC8-dependent manner.
Asunto(s)
Cromosomas de las Plantas/metabolismo , Meiosis , Proteínas Nucleares/metabolismo , Oryza/genética , Proteínas de Plantas/metabolismo , Recombinación Genética , Complejo Sinaptonémico/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Emparejamiento Cromosómico , Cromosomas de las Plantas/genética , Cromosomas de las Plantas/ultraestructura , Citocinesis , Hibridación Fluorescente in Situ , Profase Meiótica I/genética , Mutación , No Disyunción Genética , Proteínas Nucleares/genética , Oryza/fisiología , Proteínas de Plantas/genética , Polen , Complejo Sinaptonémico/ultraestructura , Telómero/ultraestructuraRESUMEN
Cellulose synthase-like (CSL) proteins of glycosyltransferase family 2 (GT2) are believed to be involved in the biosynthesis of cell-wall polymers. The CSL D sub-family (CSLD) is common to all plants, but the functions of CSLDs remain to be elucidated. We report here an in-depth characterization of a narrow leaf and dwarf1 (nd1) rice mutant that shows significant reduction in plant growth due to retarded cell division. Map-based cloning revealed that ND1 encodes OsCSLD4, one of five members of the CSLD sub-family in rice. OsCSLD4 is mainly expressed in tissues undergoing rapid growth. Expression of OsCSLD4 fluorescently tagged at the C- or N-terminus in rice protoplast cells or Nicotiana benthamiana leaves showed that the protein is located in the endoplasmic reticulum or Golgi vesicles. Golgi localization was verified using phenotype-rescued transgenic plants expressing OsCSLD4-GUS under the control of its own promoter. Two phenotype-altered tissues, culms and root tips, were used to investigate the specific wall defects. Immunological studies and monosaccharide compositional and glycosyl linkage analyses explored several wall compositional effects caused by disruption of OsCSLD4, including alterations in the structure of arabinoxylan and the content of cellulose and homogalacturonan, which are distinct in the monocot grass species Oryza sativa (rice). The inconsistent alterations in the two tissues and the observable structural defects in primary walls indicate that OsCSLD4 plays important roles in cell-wall formation and plant growth.