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151.
superwoman1-cleistogamy, a hopeful allele for gene containment in GM rice   总被引:1,自引:0,他引:1  
Cleistogamy is an efficient strategy for preventing gene flow from genetically modified (GM) crops. We identified a cleistogamous mutant of rice harbouring a missense mutation (the 45th residue isoleucine to threonine; I45T) in the class-B MADS-box gene SUPERWOMAN1 ( SPW1 ), which specifies the identities of lodicules (equivalent to petals) and stamens. In the mutant, spw1-cls , the stamens are normal, but the lodicules are transformed homeotically to lodicule–glume mosaic organs, thereby engendering cleistogamy. Since this mutation does not affect other agronomic traits, it can be used in crosses to produce transgenic lines that do not cause environmental perturbation. Molecular analysis revealed that the reduced heterodimerization ability of SPW1I45T with its counterpart class-B proteins OsMADS2 and OsMADS4 caused altered lodicule identity. spw1-cls is the first useful mutant for practical gene containment in GM rice. Cleistogamy is possible in many cereals by engineering class-B floral homeotic genes and thereby inducing lodicule identity changes.  相似文献   
152.
The meristem initiates lateral organs in a regular manner, and proper communication between the meristem and the lateral organs ensures the normal development of plants. Here, we show that mutation of the rice (Oryza sativa) gene TONGARI-BOUSHI1 (TOB1) results in pleiotropic phenotypes in spikelets, such as the formation of a cone-shaped organ instead of the lemma or palea, the development of two florets in a spikelet, or premature termination of the floret meristem, in addition to reduced growth of the lemma or palea and elongation of the awn. These phenotypes seem to result from not only failure in growth of the lateral organs, but also defects in maintenance and organization of the meristem. For example, the cone-shaped organ develops as a ring-like primordium from an initial stage, suggesting that regulation of organ initiation in the meristem may be compromised. TOB1 encodes a YABBY protein, which is closely related to FILAMENTOUS FLOWER in Arabidopsis thaliana, and is expressed in the lateral organ primordia without any patterns of polarization. No TOB1 expression is detected in the meristem, so TOB1 may act non-cell autonomously to maintain proper meristem organization and is therefore likely to play an important role in rice spikelet development.  相似文献   
153.
The (E)-3-methyl-2-hexenoic acid (E3M2H), an axillary odor-related compound, is known to occur in Caucasians. The aims of this study were to clarify whether E3M2H contributes to axillary odor in Asians and to quantify and compare individual levels of E3M2H. Quantitative determination of E3M2H was performed by means of gas chromatography-mass spectrometry of sweat extracted from the axillary areas of T-shirts worn for 24 h by Japanese subjects. The amount of E3M2H was 15.9-34.6 nmol/ml in six of 30 subjects. Our method succeeded in quantitative analysis of E3M2H from axillary sweat collected individually; we also showed that E3M2H could be detected in Asians. This is the first report in which the amount of E3M2H in axillary sweat was quantified on an individual basis and compared to reveal individual differences. The results of this study indicate that E3M2H might contribute to axillary malodor in Asians as well as Caucasians.  相似文献   
154.
A simple and rapid method using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC/MS/MS) for the simultaneous determination of 130 veterinary drugs and their metabolites in bovine, porcine, and chicken muscle was developed. The drugs (1 to 10 ng/g, in muscle) were extracted from bovine, porcine, or chicken muscles with acetonitrile-methanol (95:5, v/v), and the extracts were delipidated with n-hexane saturated with acetonitrile. The extracts were evaporated, dissolved with methanol, analyzed by liquid chromatography with gradient elution on a C18 column, and determined by electrospray ionization tandem mass spectrometry. The detection limits ranged from 0.03 to 3 ng/g. The quantitation limits ranged from 0.1 to 10 ng/g. One hundred eleven, 122, and 123 drugs from bovine, porcine, and chicken muscle respectively showed recoveries between 70 and 110%.  相似文献   
155.
Design, synthesis, and in vitro and in vivo evaluation of a series of antipsoriatic antedrugs having 16-en-22-oxa-vitamin D3 are described. Among the seven compounds examined, two are promising: ester 5c and amide 5f, both of which exhibit greater potent antiproliferation activity with lessened calcemic activity than the presently prescribed maxacalcitol (2).  相似文献   
156.
Objectives:  High-mobility group box 1 (HMGB1) is a nuclear protein that acts as a ligand of the receptor for advanced glycation end products (RAGE) and its expression enhances progression of cancer. However, the mechanism underlying HMGB1 secretion is still unclear. In this study, we examined the effect of deoxycholic acid (DCA), a promoter of colon carcinogenesis, on HMGB1 secretion.
Materials and Methods:  We used an in vitro transformation model comprised of IEC6 intestinal epithelial cells treated with azoxymethane (AOM) and/or DCA. HMGB1 expression and secretion were examined by Western and Northern blot analyses, and ELISA. Intracellular translocation of HMGB1 was examined by protein fractionation.
Results:  AOM + DCA-treated IEC6 cells showed upregulation of HMGB1 mRNA expression and increased level of HMGB1 protein in culture medium, but decreased level of HMGB1 protein in the nucleus. AOM + DCA treatment increased level of histone H4 acetylation, which induced translocation of HMGB1 from the nucleus to the cytoplasm and increased HMGB1 secretion. Leptomycin B inhibited extranuclear translocation and secretion of the HMGB1 protein.
Conclusion:  These findings suggest that DCA affects intracellular localization and secretion of HMGB1.  相似文献   
157.
Mutations in the NHS (Nance-Horan Syndrome) gene lead to severe congenital cataracts, dental defects and sometimes mental retardation. NHS encodes two protein isoforms, NHS-A and -1A that display cell-type dependent differential expression and localization. Here we demonstrate that of these two isoforms, the NHS-A isoform associates with the cell membrane in the presence of intercellular contacts and it immunoprecipitates with the tight junction protein ZO-1 in MDCK (Madin Darby Canine Kidney) epithelial cells and in neonatal rat lens. The NHS-1A isoform however is a cytoplasmic protein. Both Nhs isoforms are expressed during mouse development. Immunolabelling of developing mouse with the anti-NHS antibody that detects both isoforms revealed the protein in the developing head including the eye and brain. It was primarily expressed in epithelium including neural epithelium and certain vascular endothelium but only weakly expressed in mesenchymal cells. In the epithelium and vascular endothelium the protein associated with the cell membrane and co-localized with ZO-1, which indirectly indicates expression of the Nhs-A isoform in these structures. Membrane localization of the protein in the lens vesicle similarly supports Nhs-A expression. In conclusion, the NHS-A isoform of NHS is a novel interactor of ZO-1 and may have a role at tight junctions. This isoform is important in mammalian development especially of the organs in the head.  相似文献   
158.
159.
Although vinculin is used frequently as a marker for integrin-mediated focal adhesion complexes, how it regulates the activation of integrin is mostly unknown. In this study, we examined whether vinculin would activate integrin in Chinese hamster ovary (CHO) cells expressing human integrin αIIbβ3. Silencing of vinculin by lentiviral transduction with a short hairpin RNA sequence affected the binding of PAC-1 (an antibody recognizing activated human αIIbβ3) to a constitutively active form of αIIbβ3 (α6Bβ3) expressed on CHO cells, while its inhibitory effects were much weaker than those of talin-1. Overexpression of an active form of vinculin without intramolecular interactions, but not the full length one, induced PAC-1 binding to native αIIbβ3 expressed on CHO cells in a manner dependent on talin-1. On the other hand, silencing of talin-1, but not vinculin, failed to induce cell spreading of α6Bβ3-CHO cells on fibrinogen, even in the presence of PT 25-2, a monoclonal antibody that activates αIIbβ3. Thus, an active form of vinculin could induce αIIbβ3 inside-out signaling through the actions of talin-1, while vinculin was dispensable for outside-in signaling.  相似文献   
160.
Establishment of adaxial-abaxial polarity is essential for lateral organ development. The mechanisms underlying the polarity establishment in the stamen remain unclear, whereas those in the leaf are well understood. Here, we investigated a rod-like lemma (rol) mutant of rice (Oryza sativa), in which the development of the stamen and lemma is severely compromised. We found that the rod-like structure of the lemma and disturbed anther patterning resulted from defects in the regulation of adaxial-abaxial polarity. Gene isolation indicated that the rol phenotype was caused by a weak mutation in SHOOTLESS2 (SHL2), which encodes an RNA-dependent RNA polymerase and functions in trans-acting small interfering RNA (ta-siRNA) production. Thus, ta-siRNA likely plays an important role in regulating the adaxial-abaxial polarity of floral organs in rice. Furthermore, we found that the spatial expression patterns of marker genes for adaxial-abaxial polarity are rearranged during anther development in the wild type. After this rearrangement, a newly formed polarity is likely to be established in a new developmental unit, the theca primordium. This idea is supported by observations of abnormal stamen development in the shl2-rol mutant. By contrast, the stamen filament is likely formed by abaxialization. Thus, a unique regulatory mechanism may be involved in regulating adaxial-abaxial polarity in stamen development.  相似文献   
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