教学课程资源库 更多>>

关键词： beta ig-h3   extracellular matrix protein   fasciclin 1   fasciculation   osteogenesis   RGD-CAP   somitogenesis   zebrafish  

摘要： betaig-h3, which is structurally related to the insect fasciclin 1, is assumed to act as a cell adhesion molecule through binding to cell-surface integrins. In this study, we obtained cDNA clones for the zebrafish orthologue of betaig-h3 and examined the expression of the gene (betaig-h3) in zebrafish embryos using in situ hybridization. Expression is first seen at the bud stage in the presomitic mesoderm. Throughout the somitogenesis stage, betaig-h3 is expressed in all the segmented somites, as well as in the presomitic mesoderm (S0 and S-1). High expression is observed in the dorsolateral part of the somite until the mid-somitogenesis stage. At late somitogenesis stages, the betaig-h3 expression in the dorsolateral somite fades away, while expression is upregulated in the ventromedial part of the somite that corresponds to the sclerotome. In embryos after completion of somitogenesis and fry after hatching, betaig-h3 continues to be expressed in the sclerotome. In addition, new expression starts in the mesenchyme cells in the head, pharyngeal arches, and pectoral fins. In the embryonic brain, expression is observed along the anterior and postoptic commissures, as well as along the optic nerve. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： 人体组织学：人体胚胎学   中医学院   习题  

ISBN: (纸本)7810107526

摘要： 本书内容的编排以教材的章次为序，包括上皮组织、结缔组织、肌组织、神经组织、神经系统、循环系统、免疫系统、消化系统、呼吸系统、泌尿系统等十九章。

关键词： GFP   herbicide resistance   pearl millet   phosphinothricin   transformation  

摘要： Pearl millet [Pennisetum glaucum (L.) R. Br.] is a drought-tolerant cereal crop used for grain and forage. Novel traits from outside of the gene pool could be introduced provided a reliable gene-transfer method were available. We have obtained herbicide-resistant transgenic pearl millet plants by microprojectile bombardment of embryogenic tissues with the bar gene. Embryogenic tissues derived from immature embryos, inflorescences and apical meristems from diploid and tetraploid pearl millet genotypes were used as target tissues. Transformed cells were selected in the dark on Murashige and Skoog medium supplemented with 2 mg/l 2,4-D and 15 mg/l phosphinothricin (PPT). After 3-10 weeks in the dark, herbicide-resistant somatic embryos were induced to germinate on MS medium containing 0.1 mg/l thidiazuron and 0.1 mg/l 6-benzylaminopurine. Plants were transferred to the greenhouse after they were rooted in the presence of PPT and had passed a chlorophenol red assay (the medium turned from red to yellow). Transgenic plants were recovered from bombardments using intact pAHC25 plasmid DNA, a gel-purified bar fragment, or a mixture of pAHC25 plasmid or bar fragment and a plasmid containing the enhanced green fluorescent protein (gfp) gene (p524EGFP.1). Analyses by the polymerase chain reaction, Southern blot hybridization, GFP expression, resistance to herbicide application, and segregation of the bar and gfp genes confirmed the presence and stable integration of the foreign DNA. Transformed plants were recovered from all three explants, although transformation conditions were optimized using only the tetraploid inflorescence. Time from culture initiation to rooted transgenic plant using the tetraploid inflorescence ranged from 3-4 months. Seven independent DNA/gold precipitations were used to bombard 52 plates, 29 of which produced an average of 5.5 herbicide-resistant plants per plate. The number of herbicide-resistant plants recovered per successful bombardment ranged fro

关键词： chicken   circadian   in vitro   iodopsin transcription   photoreceptors   retina  

摘要： Retinal circadian oscillators regulate many aspects of retinal function. Investigations of these oscillators and the biochemical cascades that entrain them would be greatly facilitated if experimental paradigms could be identified that permit long-term monitoring of retinal circadian oscillator function in vitro. The purpose of this study was to determine if chicken retinas maintained in explant culture conditions could serve in this capacity. Retinal circadian oscillator function was studied by monitoring iodopsin transcription under cyclic light, constant dark, and following reversal of the light cycle. Rhythms observed in the explant cultures were compared to those observed in retinas of embryos (in ovo) and post-hatch chickens. Robust iodopsin transcript rhythms were observed for up to 9 days in explant cultures maintained under cyclic light. These rhythms persisted for 48 h in constant darkness and the time course for re-entrainment of the rhythm to a reversed light/dark cycle was similar to that observed in post-hatch chicken retinas. These results show that circadian oscillators located within the retina play a key role in the regulation of iodopsin transcription in retinal explant cultures and in retinas of post-hatch chickens. Interestingly, our data show that iodopsin transcription in retinas of intact embryos is primarily, if not entirely, driven by light. These results show that the circadian oscillators driving iodopsin. transcription in embryonic retinal explant cultures exhibit functional characteristics similar to those found in post-hatch chicken retina, supporting use of this paradigm in further studies of entrainment of these oscillators in retina. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： conversion   secondary embryogenesis   testa  

摘要： A protocol of plant regeneration through direct somatic embryogenesis was established for the first time on cashew using seed coat explants. Frequency of embryogenesis was significantly influenced by type and age of the explant and growth regulators supplemented to the medium. Seed coats isolated from the immature nuts between 15 and 40 days after pollination were superior in the induction of somatic embryos. Only 35% of seed coat halves induced somatic embryos. Somatic embryos developed best on MS medium fortified with 13.3 muM benzyladenine (BA), 271.5 muM adenine sulphate (Ads) and 2.7 muM naphthaleneacetic acid (NAA). On this medium, an average of 3.3 embryos were developed per half seed coat. Embryos originated from the inner layer of the seed coat. Transfer of the embryos to fresh induction medium facilitated development of secondary somatic embryogenesis (more than 10 embryos per primary embryo). Embryos exhibited all stages of development, i.e. from globular to cotyledonary. Fifty percent of the embryos underwent conversion upon transfer to MS medium containing 4.65 muM kinetin and plantlets were successfully transferred to field conditions. Ninety percent survived in field conditions. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： 解剖学   组织胚胎学   生理学   人体解剖学   医学教育   课程设置  

摘要： 为适应人才市场的需要,提高医护生综合素质,合理资源配置,改革分科课程,加强和提高综合课程在一些专业迫在眉睫.综合课程在比较和联系中给学生提供了丰富的背景知识,拓宽了学生的视野,加强了相邻学科的联系.

关键词： 计算机辅助教学   电子教案   组织胚胎学   小型移动存储装置  

摘要： 近年出现的小型移动存储装置具有图文容量大、可读可写,可随时修改补充、体积小巧,携带方便等优点,运用于组胚理论课教学,效果较佳.

关键词： Marek's disease virus   herpesvirus   interferon   major histocompatibility complex  

摘要： The major histocompatibility complex (MHC) is a part of the immune system which presents epitopes of intracellular antigens on the cell surface. MHC molecules have receptor-ligand binding affinities with T lymphocytes, permitting the latter to detect foreign intracellular infectious agents. Some pathogens, such as herpesviruses, have developed strategies of evading the host response by MHC. This pressure on the immune system brought, in turn, improvements in the antigen-presenting pathway, for example through the effect of interferon (IFN), which can upregulate MHC expression. The main objective of this work was on the one hand, to determine the abilities of three strains of Marek's disease virus (MDV), a chicken herpesvirus, in interfering with the expression of MHC class I molecules in chicken embryo fibroblasts. On the other hand, we analyzed the ability of IFN to reinstate this important immune capability to the infected cells. Our results show that only an oncogenic serotype I strain of MDV (RB1B) was able to markedly decrease MHC class I expression, and that addition of IFN reversed this MDV effect. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： 人体组织学   学科:医学院校   人体胚胎学  

ISBN: (纸本)7560929419

摘要： 面向21世纪基础医学辅导教材:本书根据教学大纲的要求，用精练准确的文字写出各章要求掌握的内容；每章均有各种类型的习题，包括：选择题（A型题、C型题、X型题）、名词解释、论述题，并有各类自测题的正确答案。

关键词： Cell Polarity   Laminin   细胞极性   层粘连蛋白  

摘要： Genetic analyses have revealed that members of the laminin glycoprotein family are required for basement membrane assembly and cell polarization, with subsequent effects on cell survival and tissue organization during metazoan embryogenesis. These functions depend upon the cooperation between laminin polymerization and cell anchorage mediated via interactions with beta1-integrins, dystroglycan, and other cell surface receptors.