Pollen-stigma interaction in Brassica. III. Hydration of the pollen grains

1985 ◽  
Vol 76 (1) ◽  
pp. 321-336 ◽  
Author(s):  
M.I. Zuberi ◽  
H.G. Dickinson
Keyword(s):  
Pollen Grains ◽  
The Self ◽  
Self Incompatibility ◽  
Atmospheric Water ◽  
Close Study ◽  
Direct Linkage ◽  
Brassica Pollen ◽  
Compatible Cross

A method is described by which the changes in shape that accompany hydration of Brassica pollen grains may be rapidly measured. Using this technique it has proved possible to chart the small amount of hydration that takes place on anthesis, in addition to the response of pollen to a range of relative humidities in vitro and in vivo. Such measurements, together with pollen transfer experiments, indicate that under normal field conditions self-pollen undergoes a brief period of hydration followed by some loss of water and that, in the course of this hydration, many pollen grains are inhibited from further growth. Raised levels of atmospheric water cause a variety of responses in self-pollen, ranging from tube growth through the pistil to the ovary, to tubes inhibited at the stigmatic surface, accompanied by the formation of callose. Surprisingly, compatible cross-pollen is also affected by high humidity, often developing extended tubes that are incapable of penetrating the stigmatic cuticle. The development of stigmatic callose is also stimulated by these tubes, as also occurs when other members of the Cruciferae are induced to germinate on Brassica stigmas by high levels of atmospheric water. This formation of callose in response to challenge by all types of pollen tube suggests models for the self-incompatibility response in Brassica that involve a direct linkage between S (incompatibility) gene products and the formation of callose may require some reexamination. Close study of the operation of the self-incompatibility system in a number of individuals has revealed all aspects of the response to be heavily dependent on the particular S genes possessed by the plant.

scholarly journals Effects of different pollination treatments in genotypes of Prunus salicina Lindl.

2006 ◽  
Vol 12 (2) ◽  
Author(s):  
M. Ontivero ◽  
S. Radice ◽  
E. Giordani ◽  
E. Bellini
Keyword(s):  
Pollen Grains ◽  
Fruit Production ◽  
Self Incompatibility ◽  
Open Pollination ◽  
Cross Pollination ◽  
Prunus Salicina ◽  
Germination Of Pollen ◽  
Selection Of

The low productivity in the Japanese plum (Prunus salicina Lindl) is related with self-incompatibility characteristics, so other species or varieties that act as pollinators need to be present to improve fruit production. The objective of this work was to study the efficiency of pollination in different genotypes of P. salicina using treatments of natural self-pollination, cross-pollination with P. armeniaca cv. Giada and open pollination. These treatments were evaluated through viability techniques and in vitro and in vivo germination of pollen grains; the growth of pollen tubes along the pistil was also observed. Genotypes used in this study showed differences for each one of the pollination treatments. Some genotypes showed signs of self-sterility and interincompatibility with P. armeniaca cv. Giada, while others showed partial self-fertility characteristics or pseudocompatibility. Moreover, some genotypes showed a higher affinity coefficient with cv. Giada and these will be indicating a possible intercompatibility. These studies will be an important contribution breeding and selection of intra and intercompatible genotypes to be used in commercial orchards.

scholarly journals Action of the Style Product of the Self-Incompatibility Gene of Nicotiana alata (S-RNase) on in Vitro-Grown Pollen Tubes.

1991 ◽  
pp. 271-283 ◽  
Author(s):  
J. E. Gray ◽  
B. A. McClure ◽  
I. Bonig ◽  
M. A. Anderson ◽  
A. E. Clarke
Keyword(s):  
Pollen Tubes ◽  
The Self ◽  
Nicotiana Alata ◽  
Self Incompatibility

The formation of the tryphine coating the pollen grains of Raphanus , and its properties relating to the self-incompatibility system

1973 ◽  
Vol 184 (1075) ◽  
pp. 149-165 ◽  
Keyword(s):  
Granular Material ◽  
Pollen Grains ◽  
The Self ◽  
Self Incompatibility ◽  
Pollen Maturation ◽  
Incompatible Pollen ◽  
Incompatibility System ◽  
Two Stages ◽  
Stimulation Of ◽  
Incompatible Pollen Tube

The tryphine that coats the pollen grains of Raphanus is tapetally synthesized and is composed of a fibro-granular and a lipidic component. The fibro-granular material is proteinaceous and is secreted by cisternae of the endoplasmic reticulum. The lipidic component is derived, mainly, from degraded elaioplasts. The fibro-granular material is applied to the pollen exine first, followed by the lipidic mass. The tryphine condenses during the final stages of pollen maturation and dries down to form a thick, highly viscous coating. The major part of the condensation appears to result from dehydration. The tryphine, extracted from the pollen by a centrifugal method and mounted in a membrane, appears to be capable of penetrating the outer layers of a stigma of the same species and, if the pollen from which it was derived is incompatible with respect to the stigma, the stimulation of the production of the callosic reaction body in a manner similar to an incompatible pollen tube. It is proposed that, in Raphanus , substances responsible for the initiation of at least two stages in the self-incompatibility system are held in the tryphine.

Enhanced Oral Bioavailability and Improved Biological Activities of a Quercetin/Resveratrol Combination Using a Liquid Self-Microemulsifying Drug Delivery System

Planta Medica ◽  
2020 ◽  
Author(s):  
Patcharawalai Jaisamut ◽  
Subhaphorn Wanna ◽  
Surasak Limsuwan ◽  
Sasitorn Chusri ◽  
Kamonthip Wiwattanawongsa ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Oral Bioavailability ◽  
Biological Activities ◽  
Area Under The Curve ◽  
Aqueous Solubility ◽  
The Self

AbstractBoth quercetin and resveratrol are promising plant-derived compounds with various well-described biological activities; however, they are categorized as having low aqueous solubility and labile natural compounds. The purpose of the present study was to propose a drug delivery system to enhance the oral bioavailability of combined quercetin and resveratrol. The suitable self-microemulsifying formulation containing quercetin together with resveratrol comprised 100 mg Capryol 90, 700 mg Cremophor EL, 200 mg Labrasol, 20 mg quercetin, and 20 mg resveratrol, which gave a particle size of 16.91 ± 0.08 nm and was stable under both intermediate and accelerated storage conditions for 12 months. The percentages of release for quercetin and resveratrol in the self-microemulsifying formulation were 75.88 ± 1.44 and 86.32 ± 2.32%, respectively, at 30 min. In rats, an in vivo pharmacokinetics study revealed that the area under the curve of the self-microemulsifying formulation containing quercetin and resveratrol increased approximately ninefold for quercetin and threefold for resveratrol compared with the unformulated compounds. Moreover, the self-microemulsifying formulation containing quercetin and resveratrol slightly enhanced the in vitro antioxidant and cytotoxic effects on AGS, Caco-2, and HT-29 cells. These findings demonstrate that the self-microemulsifying formulation containing quercetin and resveratrol could successfully enhance the oral bioavailability of the combination of quercetin and resveratrol without interfering with their biological activities. These results provide valuable information for more in-depth research into the utilization of combined quercetin and resveratrol.

scholarly journals Histone demethylase JMJD2D promotes the self-renewal of liver cancer stem-like cells by enhancing EpCAM and Sox9 expression

2020 ◽  
pp. jbc.RA120.015335
Author(s):  
Yuan Deng ◽  
Ming Li ◽  
Minghui Zhuo ◽  
Peng Guo ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Cancer Progression ◽  
Liver Tumors ◽  
The Self ◽  
High Rate ◽  
Sox9 Expression ◽  
Self Renewal ◽  
Lysine Demethylase

Cancer stem-like cells (CSCs) contribute to the high rate of tumor heterogeneity, metastasis, therapeutic resistance, and recurrence. Histone lysine demethylase 4D (KDM4D or JMJD2D) is highly expressed in colon and liver tumors, where it promotes cancer progression; however, the role of JMJD2D in CSCs remains unclear. Here, we show that JMJD2D expression was increased in liver cancer stem-like cells (LCSCs); downregulation of JMJD2D inhibited the self-renewal of LCSCs in vitro and in vivo and inhibited the lung metastasis of LCSCs by reducing the survival and the early lung seeding of circulating LCSCs. Mechanistically, JMJD2D promoted LCSC self-renewal by enhancing the expression of CSC markers EpCAM and Sox9; JMJD2D reduced H3K9me3 levels on the promoters of EpCAM and Sox9 to enhance their transcription via interaction with β-catenin/TCF4 and Notch1 intracellular domain, respectively. Restoration of EpCAM and Sox9 expression in JMJD2D-knockdown liver cancer cells rescued the self-renewal of LCSCs. Pharmacological inhibition of JMJD2D using 5-c-8HQ reduced the self-renewal of LCSCs and liver cancer progression. Collectively, our findings suggest that JMJD2D promotes LCSC self-renewal by enhancing EpCAM and Sox9 expression via Wnt/β-catenin and Notch signaling pathways and is a potential therapeutic target for liver cancer.

The Regulation of β-arrestin1 in Leukemia Initiating Cells of Children B-Acute Lymphoblastic Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3538-3538
Author(s):  
Lin Zou ◽  
Shan Liu ◽  
Yi Shu ◽  
Ru Qin ◽  
Kang Li ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Mrna Expression ◽  
Promoter Region ◽  
Lymphoblastic Leukemia ◽  
The Self ◽  
Mrna Expression Level ◽  
Self Renewal ◽  
Nsg Mice

Abstract Background Leukemia is the most common malignant tumor in children under 15 years old. The main subtype of children leukemia is acute lymphoblastic leukemia (ALL), and B-lineage ALL (B-ALL) accounts for approximately 70%. The leukemia-initiating cells (LICs) are cancer stem cells with long-term repopulating potential and propagation ability, to maintain the leukemia cell phenotype, and possess leukemia-initiating activity. However, the regulation of LICs for the leukemia progression is poorly understood. The multifunctional scaffold proteins β-arrestins are proven to mediate H4 acetylation and gene expression. And β-arrestin2 is found to regulate the initiation and progression of chronic myeloid leukemia (CML). However, the role of β-arrestin1 in B-ALL is still unknown. Our preliminary data showed that both the high expression of β-arrestin1 and high proportion of CD34+CD38- cells are positively correlated with risk stratification and poor prognosis of childhood B-ALL. And β-arrestin1 binds with EZH2 to increase BCR/ABL H4 acetylation and thus promotes CML cell progression in vitro and in vivo. The aim of study is to investigate the essential function of β-arrestin1 in LICs from B-ALL. Materials and Methods The bone marrow (BM) and periphery blood (PB) of children B-ALL patients were collected, isolated and identified LICs by Magnetic-activated cell sorting (MACS) and flow cytometry. The total RNA and protein were purified for gene and protein expression by real-time RT-PCR and Western blot. The leukemia cells (LICs, Raji, and Reh) of β-arrestin1 depletion were constructed by transient or stable screening si-β-arrestin1 (siβ1) lentivirus vector. The serial cell colony formation and NSG mice survival analysis was measured the LICs self-renewal ability. The CCK8 and MTS assays were used to detect the cell proliferation, and annexin V-FITC and PI staining for cell apoptosis. The DNA methylation of gene promoter region was detected by methylation-specific PCR and the methltransferase activity by ELISA. The telomere length was indicated by Southern blot and FISH, and telomerase activity by TRAP. Electrophoretic mobility shift assay (EMSA) and dual-luciferase reporter assay were applied to explain gene transcription. Student’s t test and Log-Rank test were used in the corresponding statistical significance and P<0.05 were considered significant. All the statistical analysis was performed using the GraphPad Prism (Version 5.0) software packages and SPSS 17.0. Results The expression of β-arrestin1 was elevated in LICs from B-ALL patients, and the high level of β-arrestin1 was negatively correlated with the survival of these patients. Further study showed that the loss of β-arrestin1 in B-ALL LICs attenuates their self-renewal capacity and promotes their senescence in vitro and in vivo. The mRNA expression level of β-arrestin1 is negatively correlated with that of PTEN in LICs. Moreover, the DNA methylation of the PTEN promoter region, the activity and the expression of DNMTs were enhanced in the LICs. The inhibition of DNMT1 activity impaired the self-renewal and increased the expression of PTEN of LICs. In addition, depletion of β-arrestin1 significantly decreased DNMT1 activity and PTEN methylation, and consistently increased PTEN expression in LICs. For B-ALL cell senescence, the mRNA expression level of β-arrestin1 is negatively related with the length of telomere, positively related with the activity of telomerase and the mRNA expression of hTERT in B-ALL LICs and engrafted NSG mice. Moreover, the weakened effect of β-arrestin1 on telomere, telomerase and the gene of hTERT were observed by injected the inhibitor of telomerase in leukemic mice. In addition, depletion of β-arrestin1 significantly decreased the binding of SP1 to the promoter of hTERT and thus reduced the transcription of hTERT in B-ALL Raji and Reh cells. Furthermore, β-arrestin1 interacted with P300 to bind with SP1 in the -104bp to -113bp of hTERT core promoter region in B-ALL cells. Conclusions β-arrestin1 could regulate the self-renewal and senescence of LICs from B-ALL, by partially mediating DNMT1 activity and hTERT transcription respectively, indicating that β-arrestin1 is a potential therapeutic target for B-ALL. Disclosures No relevant conflicts of interest to declare.

scholarly journals Preparation, cellular uptake and angiogenic suppression of shikonin-containing liposomes in vitro and in vivo

2013 ◽  
Vol 33 (2) ◽  
Author(s):  
Hongmei Xia ◽  
Chengyi Tang ◽  
Heng Gui ◽  
Xiaoming Wang ◽  
Jinliang Qi ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Cellular Uptake ◽  
Mtt Assay ◽  
Chorioallantoic Membrane ◽  
The Self ◽  
Clinical Use ◽  
Phospholipid Membrane ◽  
Soybean Phospholipid

Shikonin has anticancer activity, but it has not yet been applied into clinical use. In the present study, shikonin was prepared using liposomes. We aimed to examine several aspects of sh-L (shikonin-containing liposomes): preparation, angiogenic suppression and cellular uptake through self-fluorescence. Sh-L were prepared using soybean phospholipid and cholesterol to form the membrane and shikonin was encapsulated into the phospholipid membrane. Three liposomes were prepared with shikonin. They had red fluorescence and were analysed using a flow cytometer. Angiogenic suppression of sh-L was determined using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide], Transwell tests, chick CAM (chorioallantoic membrane) and Matrigel™ plug assay. MTT assay showed the median IC50 (inhibitory concentrations) as follows: shikonin, sh-L1 and sh-L2 were 4.99±0.23, 5.81±0.57 and 7.17±0.69 μM, respectively. The inhibition rates of migration were 53.58±7.05, 46.56±4.36 and 41.19±3.59% for 3.15 μM shikonin, sh-L1 and sh-L2, respectively. The results of CAM and Matrigel plug assay demonstrated that shikonin and sh-L can decrease neovascularization. Effect of shikonin was more obvious than sh-L at the same concentration. The results showed that sh-L decreased the toxicity, the rate of inhibition of migration and angiogenic suppression. The cellular uptake of the sh-L could be pictured because of the self-fluorescence. The self-fluorescence will be useful for conducting further research. Sh-L might be an excellent preparation for future clinical application to cancer patients.

The effect of gonadotrophin surge-inhibiting factor on the self-priming action of gonadotrophin-releasing hormone in female rats in vitro

1992 ◽  
Vol 134 (3) ◽  
pp. 427-436 ◽  
Author(s):  
D. W. Koppenaal ◽  
A. M. I. Tijssen ◽  
J. de Koning
Keyword(s):  
Protein Synthesis ◽  
Priming Effect ◽  
The Self ◽  
Pituitary Cells ◽  
Inhibiting Factor ◽  
Lh Release ◽  
Gonadotrophin Releasing Hormone ◽  
Functional Antagonism

ABSTRACT The present study was designed to explore further the functional antagonism between gonadotrophin-releasing hormone (GnRH) and the ovarian factor, gonadotrophin surge-inhibiting factor (GnSIF). In all experiments, pituitary tissue was exposed to various amounts of GnSIF, after which the self-priming action of GnRH was studied. GnSIF was increased in vivo by FSH treatment and increased in vitro by adding various amounts of follicular fluid (FF) to cultured pituitary cells. Treatment with 3 or 10 IU FSH suppressed the initial LH response and delayed the maximally primed LH response to GnRH. Treatment with FSH was only effective in intact rats on days 1 and 2 of dioestrus. There was no difference in the rate of maximal LH release irrespective of treatment with either FSH or saline. Since FSH treatment was ineffective in long-term ovariectomized rats, it was concluded that the initial suppressive effect of FSH on LH release was mediated by GnSIF. Cycloheximide prevented the self-priming action of GnRH by inhibiting GnRH-induced protein synthesis. The initial protein synthesis-independent GnRH-stimulated LH release, which was already suppressed by FSH treatment, remained suppressed in the presence of cycloheximide. Pretreatment with GnRH in vivo increased the protein synthesis-independent GnRH-induced LH release during subsequent incubation of the glands. This increase did not occur after FSH treatment. Pituitary cells, cultured for 20 h in medium only, failed to elicit the self-priming effect of GnRH. Preincubation with FF maintained the self-priming effect. This was independent of the concomitant presence of various amounts of oestradiol. Preincubation with bovine FF suppressed the initial GnRH-stimulated LH release dose-dependently. Porcine FF, human FF and testicular extract suppressed the release of LH in a similar way. It was concluded that GnSIF suppresses the initial LH response to continuous GnRH stimulation. Increased levels of GnSIF caused by FSH treatment also delayed the primed LH release. The mechanism of functional antagonism between GnSIF and GnRH could give rise to the occurrence of the phenomenon of GnRH self-priming. Journal of Endocrinology (1992) 134, 427–436

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