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11.
Michael G. Gabridge Edward P. Dougherty Martha F. Gladd Rose A. Meccoli 《In vitro cellular & developmental biology. Plant》1982,18(12):1023-1032
Summary Tracheal explants were used to evaluate the relative ciliostatic and cytotoxic potential of heavy metal salts (cadmium chloride,
chromium chloride, nickel chloride, and copper sulfate). Explants from hamster, rat, and guinea pig were all sensitive to
the metals, though guinea pig explants showed the greatest difference between the untreated and metal treated tissues. Dosage
levels were 50, 100, and 500μM, for 24 to 148 h. Cadmium caused the greatest degree of ciliostasis and cell necrosis. Copper was less toxic, and nickel
and chromium caused marginal damage when tested at 100μM or lower. In each instance, damage became detectable at approximately 24 to 48 h and was nearly stabilized by 72 h. A significant
loss of ciliary motion was always accompanied by a decrease in metabolic activity (dehydrogenase activity and ATP content).
Transmission and scanning electron microscopy revealed a severely necrotic epithelium after exposure to cadmium, with only
subtle morphological alterations after exposure to other metals. With all of the treatments there was no overt structural
damage to cilia and little alteration in membranes of cells remaining in the epithelium. Some coagulation or vacuolization
was noted in cadmium and copper treated explants but most cellular organelles did not display obvious damage. The most significant
changes in the tracheal epithelium exposed to heavy metal salts in vitro were a loss of ciliary motion and a decrease in total
ATP content.
This study was supported in part by Grant HL 26880 from the National Heart, Lung and Blood Institute, Bethesda, MD. 相似文献
12.
《Cell cycle (Georgetown, Tex.)》2013,12(15):2765-2766
Comment on: Tran KV, et al. Cell Metab 2012; 15:222-9. 相似文献
13.
Karl-Frederik Bergeron Tatiana Cardinal Nicolas Pilon 《Journal of visualized experiments : JoVE》2013,(79)
Neural crest cells (NCC) are a transient and multipotent cell population that originates from the dorsal neural tube and migrates extensively throughout the developing vertebrate embryo. In addition to providing peripheral glia and neurons, NCC generate melanocytes as well as most of the cranio-facial skeleton. NCC migration and differentiation is controlled by a combination of their axial origin along the neural tube and their exposure to regionally distinct extracellular cues. Such contribution of extracellular ligands is especially evident during the formation of the enteric nervous system (ENS), a complex interconnected network of neural ganglia that locally controls (among other things) gut muscle movement and intestinal motility. Most of the ENS is derived from a small initial pool of NCC that undertake a long journey in order to colonize - in a rostral to caudal fashion - the entire length of the prospective gut. Among several signaling pathways known to influence enteric NCC colonization, GDNF/RET signaling is recognized as the most important. Indeed, spatiotemporally controlled secretion of the RET ligand GDNF by the gut mesenchyme is chiefly responsible for the attraction and guidance of RET-expressing enteric NCC to and within the embryonic gut. Here, we describe an ex vivo cell migration assay, making use of a transgenic mouse line possessing fluorescently labeled NCC, which allows precise quantification of enteric NCC migration potential in the presence of various growth factors, including GDNF. 相似文献
14.
以成熟和未成熟合子胚为外植体,研究影响兴安落叶松(Larix gmelinii)胚性愈伤组织诱导的几种主要因子。结果表明兴安落叶松合子胚带胚乳培养有利于胚性愈伤组织的诱导;内蒙沙地种源成熟合子胚的诱导率显著(p<0.05)高于加格达奇山地种源;冷藏处理可以提高成熟合子胚胚性愈伤组织的诱导率;不同发育时期的未成熟合子胚的诱导率存在显著差别(p<0.05),其中以子叶初期合子胚(7月5日)诱导率最高;2,4-D对胚性愈伤组织诱导的影响较大,且与BA、KT存在一定的协同作用;S培养基比DCR和MS培养基更有利于胚性愈伤组织的诱导;培养基中琼脂含量为4 g·L-1时,诱导率较高。 相似文献
15.
A protocol based on SAAT (sonication-assisted Agrobacterium-mediated transformation) has been developed to obtain herbicide-resistant transgenic black locust (Robinia pseudoacacia L.) plants. Cotyledon explants were co-cultivated with Agrobacterium AGL1 strain carrying the pTAB16 plasmid (bar and gusA genes). The effects of bacterial concentration (OD550 of 0.3, 0.6, 0.8) and method of infection (sonication vs immersion) on bacterial delivery were determined by assaying cotyledons for transient -glucuronidase expression 3 days after infection. SAAT increases transient expression efficiency especially at an OD550 of 0.6. After determining bacterial concentration and infection method, other factors affecting transformation efficiency, such as explant preconditioning and period of time before applying selection, were tested. From these experiments, the preferred protocol for black locust cotyledon transformation should include sonication of preconditioned cotyledons in AGL1 suspension, coculture for 3 days with 100 µM acetosyringone and transfer to selection medium with 4 mg/l phosphinothricin and 150 mg/l timentin. Of the initial explants, 2% produced at least one transgenic shoot. Genetic transformation was confirmed by Southern hybridization, chlorophenol red assay and herbicide tolerance of the regenerated plants.Abbreviations AS Acetosyringone - BA N-(Phenylmethyl)-1H-purin-6-amine (benzyladenine) - CR Chlorophenol red - 2,4-D 2,4-Dichlorophenoxyacetic acid - GUS -Glucuronidase - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - PPT PhosphinothricinCommunicated by P. Ozias-Akins 相似文献
16.
Leaf segments excised from Centella asiatica, a medicinal and neutraceutical plant, produced abundant somaticembryoswhen cultured onMS mediumwith 9.29 Mkinetin in combination with 2.26 M2,4-D. Granular, white,shiny clusters of callus developed after 1 week of culture, and then formed heart and cotyledonary stage embryoson the same medium after 4 weeks. Somatic embryos matured and germinated in the presence of MS mediumcontaining 2.32 M kinetin with (2.89M) GA3. Plantlets were successfully transferred to pots containing amixture of soil and vermiculite (1:1). 相似文献
17.
Yasseen?Mohamed-YasseenEmail author 《In vitro cellular & developmental biology. Plant》2002,38(5):423-426
Summary A procedure for plant regeneration, flower and plant formation from petiolar and inflorescence nodal explants of culantro
is discribed. Leaf petioles were excised from young leaves of non-flowering plants while nodal explants were excised from
the inflorescence. Explants were cultured in Murashige and Skoog (MS) medium alone or supplemented with 0.5μM naphthaleneacetic acid (NAA) and 0.9, 1.8, 4.5, or 9 μM thidiazuron (TDZ). All explants produced multiple shoots. In addition, nodal explants formed flowers. Shoot number, flower
number and shoot length were influenced by TDZ and NAA. Rooted shoots from both types of explants were transferred to soil
where plants were successfully established. 相似文献
18.
An improved micropropagation protocol has been developed for teak (Tectona grandis). Nodal explants placed on MS medium supplemented with 22.2 M benzylaminopurine and then serially transferred to fresh medium after 12, 24, 48 and 72 h gave maximum culture establishment (76.8%). Establishment was reduced when explants were retained in the initial culture medium longer than 12 h. Explants collected in May showed maximum (76.8%) response. Placement of the explants on MS medium supplemented with 22.2 M benzylaminopurine and 0.57 M indole-3-acetic acid resulted in the maximum average number of shoots. In vitro raised micro shoots were rooted ex vitro by dipping in indole-3-butyric acid (9.8 mM) for 2 min followed by planting in polyethylene pots containing a soil:vermiculite (1:1 v/v) mixture. This treatment resulted in 77.9% survival of the plantlets. They were weaned in a glasshouse and finally moved to an agro-net shade house. 相似文献
19.
Efficient Agrobacterium -mediated transformation of Antirrhinum majus L. was achieved via indirect shoot organogenesis from hypocotyl explants of seedlings. Stable transformants were obtained by inoculating explants with A. tumefaciens strain GV2260 harboring the binary vector pBIGFP121, which contains the neomycin phosphotransferase gene (NPT II) as a selectable marker and the gene for the Green Fluorescent Protein (GFP) as a visual marker. Putative transformants were identified by selection for kanamycin resistance and by examining the shoots using fluorescence microscopy. PCR and Southern analyses confirmed integration of the GFP gene into the genomes of the transformants. The transformants had a morphologically normal phenotype. The transgene was shown to be inherited in a Mendelian manner. This improved method requires only a small number of seeds for explant preparation, and three changes of medium; the overall transformation efficiency achieved, based on the recovery of transformed plants after 4–5 months of culture, reached 8–9%. This success rate makes the protocol very useful for producing transgenic A. majus plants.Communicated by G. Jürgens 相似文献
20.
Perumal Venkatachalam Natesan Geetha Narayanasamypillai Jayabalan 《Journal of Plant Biology》1998,41(1):1-8
This study was designed to evaluate the effect of phytohormones on plant regeneration from epicotyl and hypocotyl explants
of two groundnut (Arachis hypogaea) cultivars. Explants cultured on media with auxins and in combination with cytokinin produced high frequency of callus. After
four weeks, callus from these cultures was transferred to medium with cytokinin and reduced auxin, shoot buds regenerated
from the cultures. A high rate of shoot bud regeneration was observed on medium supplemented with 2.0 mg/L BAP and 0.5 mg/L
NAA. Among the different auxins tested, NAA was found to be most effective, producing the highest frequency of shoot buds
per responding cultures. Of the two explants tested, epicotyl was found to be best for high frequency shoot bud regeneration.
Multiple shoots arose on MS medium supplemented with BAP or kinetin (1.0–5.0 mg/L) plus IBA (1.0 mg/L), with maximum production
occurring at 5.0 mg/L. The elongated shoots developed rootsin vitro upon transfer to MS medium supplemented with NAA or IBA (0.5–2.0 mg/L) and kinetin (0.5 mg/L) for 15 days.In vitro produced plantlets, were transferred to soil and placed in a glasshouse developed successfully, matured, and set seeds. 相似文献