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关键词： 《组织学和胚胎学》   医学专科教育   教材建设  

摘要： 专科第三版教材就以前相比,有了很大的改进,并且具有自己的一些特色,这一点在杭州医学院的王祖武的文章中也有说明,这里不再赘述,文中也就教材中的一些错误指出了部分,但我们在教材的使用过程中发现有些地方虽没有指出来,但存在一些问题值得商榷,故在本文中作一些说明.

关键词： 四合木   愈伤组织   体细胞胚胎发生   淀粉粒  

摘要： 本文对四合木 (TetrenamongolicaMaxim)种子萌发 12d产生的无菌苗为外植体进行离体培养。通过在MS培养基上附加 2 ,4—D　 0 5mg/L ,6—BA　 0 1mg/L培养基上诱导愈伤组织和在分化培养基 2 ,4—D　0 2 5mg/L和 6—BA　 0 5mg/L培养过程中 ,组织切片观察结果表明 ,淀粉粒在体细胞胚胎发生过程中积累的变化 。

关键词： 观点   方法   组织学   胚胎学  

摘要： 本文主要围绕如何学好组胚学,阐述了其观点和方法。对于初学者来说,特别应注意这些问题,在学习中不断摸索和总结,才有可能尽快地进入学习和研究组织学与胚胎学的领地,并轻松了解和掌握人体细微结构及微观领域里的奥妙。

关键词： auxin   cytokinin   Elaeis guineensis Jacq.   tissue culture   transfer interval   variation  

摘要： New and established embryoid lines of oil palm (Elaeis guineensis Jacq.) clones, classified with regard to the expected risk of mantled flowering, were included in experiments to determine to what extent culture conditions during 48 weeks of embryoid multiplication could influence the incidence and severity of mantled flowering. Variables tested included clone risk status, duration of transfer interval, and plant growth regulator composition of the culture medium. Clones classified as high risk at the outset gave a significantly higher incidence of mantled flowering in the field than clones classified as low/medium risk, confirming that data on terminal inflorescences produced in vitro allows effective screening of material with regard to the risk of mantled flowering. The incidence of mantled flowering ranged from 0 to 100% depending on risk status of the clones, and the treatments applied. In general, a relatively long transfer interval (8 weeks) and a high auxin/cytokinin ratio resulted in the lowest incidence of mantled flowering with all types of material. Reducing the transfer interval down to 2 or 4 weeks, and/or using media with relatively high concentrations of kinetin (0.25 mg l(-1)), and low concentrations of naphthalene acetic acid (0 or 0.1 mg l(-1)), resulted in a high incidence of mantled flowering (above 30%), even with low/medium risk clones. Exclusion of plant growth regulators from the embryoid multiplication medium did not prevent some mantled flowering (12%) of new embryoid lines of low/medium risk clones following embryoid multiplication on a 4 week transfer interval, and a much higher incidence of mantling (above 90%) of lines from high risk clones.

关键词： optic vesicle   dorsal-ventral axis   chick   transplantation   choroid fissure   Pax2   Tbx5  

摘要： Dorsal and ventral specification in the early optic vesicle appears to play a crucial role in the proper development of the eye. In the present study, we performed embryonic transplantation and organ culturing of the chick optic vesicle in order to investigate how the dorsal-ventral (D-V) polarity is established in the optic vesicle and what role this polarity plays in proper eye development. The left optic vesicle was cut and transplanted inversely in the right eye cavity of host chick embryos. This method ensured that the D-V polarity was reversed while the anteroposterior axis remained normal. The results showed that the location of the choroid fissure was altered from the normal (ventral) to ectopic positions as the embryonic stage of transplantation progressed from 6 to 18 somites. At the same time, the shape of the optic vesicle and the expression patterns of Pax2 and Tbx5, marker genes for ventral and dorsal regions of the optic vesicle, respectively, changed concomitantly in a similar way. The crucial period was between the 8- and 14-somite stages, and during this period the polarity seemed to be gradually determined. In ovo explant culturing of the optic vesicle showed that the D-V polarity and choroid fissure formation were already specified by the 10-somite stage. These results indicate that the D-V polarity of the optic vesicle is established gradually between 8- and 14-somite stages under the influence of signals derived from the midline portion of the forebrain. The presumptive signal(s) appeared to be transmitted from proximal to distal regions within the optic vesicle. A severe anomaly was observed in the development of optic vesicles reversely transplanted around the 10-somite stage: the optic cup formation was disturbed and subsequently the neural retina and pigment epithelium did not develop normally. We concluded that establishment of the D-V polarity in the optic vesicle plays an essential role in the patterning and differentiation of the neural

关键词： 组织胚胎学   教学   教学质量  

摘要： 现代医学教育在体制、人才培养的模式、教学内容和教学方法等方面与西方的尚存在一定的差距,从而影响医学生综合素质的提高[1].值此科学技术突飞猛进,信息交往频繁,竞争异常激烈的时期,如何培养专业人才的综合分析能力,是摆在我们面前的艰巨任务.

关键词： 禾本科植物   组织培养   体细胞胚胎发生   基因型   器官分化   细胞形态  

摘要： 对禾本科植物培养中器官分化和体细胞胚胎发生研究的现状做了介绍,并对其培养物的细胞形态等特殊性征和基因型在其中所起的作用进行了分析。

关键词： 组织胚胎学   教学改革   多媒体课件   网络教育   医学教学  

摘要： 利用现代多媒体技术和网络资源,改革组织胚胎学传统的教学方法和手段,可以大大改善教学效果,提高教学质量,培养创新性的医学人才.

关键词： Agrobacterium rhizogenes   hairy root   plant regeneration   somatic embryogenesis   spinach  

摘要： Hairy roots of spinach (Spinacia oleracea L.) were obtained by inoculation of cotyledon explants with wild-type Agrobacterium rhizogenes A13. Integration of the transfer DNA (T-DNA) of a root-inducing (Ri) plasmid of A. rhizogenes into the plant DNA was confirmed by the polymerase chain reaction. Somatic embryogenesis from explants of hairy roots were induced even when the callus-induction (CI) medium did not contain gibberellic acid (GA(3)) which is considered to be a key growth regulator that is critical for induction of somatic embryogenesis in spinach. Proteins extracted from hairy root-derived calli and from non-transformed root-derived calli generated on medium that contained 10 muM naphthaleneacetic acid (NAA), without GA(3), were analyzed by polyacrylamide gel electrophoresis. The proteins from the former calli included appreciably higher levels of a 31-kDa basic protein (BP31) (pI=8.8) than proteins from the latter. This 31-kDa protein also accumulated in embryogenic calli derived from non-transformed roots. Somatic embryos from hairy root explants, grown on medium without growth regulators, yielded regenerated plantlets with actively growing root systems and shoots that did not bolt. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.