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1.
Plant somatic cells have the capability to switch their cell fates from differentiated to undifferentiated status under proper
culture conditions, which is designated as totipotency. As a result, plant cells can easily regenerate new tissues or organs
from a wide variety of explants. However, the mechanism by which plant cells have such remarkable regeneration ability is
still largely unknown. In this study, we used a set of meristem-specific marker genes to analyze the patterns of stem cell
differentiation in the processes of somatic embryogenesis as well as shoot or root organogenesis in vitro. Our studies furnish preliminary and important information on the patterns of the de novo stem cell differentiation during various types of in vitro organogenesis. 相似文献
2.
Food availability is important to the dynamics of animal social organizations or populations. However, the role of winter
food availability in animal population dynamics is still controversial. We carried out an experimental study to test Lack’s
hypothesis that reduced food in winter limits survival and spring numbers of breeding individuals of social groups, using
the Mongolian gerbil (Meriones unguiculatus) as model species. We established 24 gerbil social groups in 24, 10 × 10 m, pens in September 2008. We provided wheat seeds
as supplemental food in 12 enclosures from September 2008 to March 2009; the other 12 enclosures, not provided with supplemental
food, served as controls. We live-trapped gerbils at a 2-week interval from September to April. Supplemental food during winter
increased biweekly survival by 10% relative to that in control groups. Only four control social groups survived to the end
of our study whereas all 12 food-supplemented social groups survived through our study period. Supplemental food also increased
cumulative numbers of recruits and group sizes of gerbils. We conclude that winter food availability limits winter survival
and spring social groups or population sizes of Mongolian gerbils. 相似文献
3.
4.
贝壳历来是生物工程和材料学研究的重要对象。贝壳中的贝壳基质蛋白质在贝壳的形成与发育过程中具有重要的调控作用。Whirlin类蛋白质(Whirlin-like protein,WLP)是一种从厚壳贻贝(Mytilus coruscus)中鉴定的新型贝壳基质蛋白质。序列分析结果显示,该蛋白质含有PDZ(postsynaptic density/Discs large/Zonula occludens)结构域,而该结构域对贝壳生物矿化的影响目前尚无报道。为深入了解WLP在贝壳形成中对碳酸钙晶体的影响,在序列分析基础上,采用密码子优化结合原核重组表达,获得其重组表达产物后,开展了重组WLP对碳酸钙晶体形貌及晶型的影响研究,结晶速度抑制以及碳酸钙晶体结合分析。分析结果表明,重组WLP能诱导文石型碳酸钙晶体的形貌和方解石型碳酸钙晶体的晶型发生改变;同时重组WLP对碳酸钙晶体具有结合作用,且能抑制碳酸钙晶体的结晶速度。上述结果表明,WLP对贝壳的形成及发育具有重要影响,并可能在贝壳肌棱柱层的形成中发挥了重要作用。 相似文献
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6.
An interspecific somatic hybrid between Actinidia chinensis and Actinidia kolomikta and its chilling tolerance 总被引:2,自引:0,他引:2
Protoplasts isolated from cotyledon-derived callus of Actinidia chinensisPlanch. var. chinensis (2N=2x=58) were fused with mesophyll protoplasts of Actiniadia kolomikta(Maxim. et Rupr.) Maxim (2N=2x=58) using a PEG method. Plantlets were regenerated from the fusion product clone 11. RAPD analyses, chromosome numbers of root tip cells and fluorescence peak position of leaf nuclei confirmed that clone 11 was an interspecific somatic hybrid (2N=4x=116) between A. chinensis and A. kolomikta. The chilling tolerance of the somatic hybrid was tested with in vitro leaves at low temperatures. Based on data of leaf thickness, electroconductivity, proline levels, malondialdehyde content and activity of superoxide dismutase, dendrogram cluster analysis suggested that the interspecific somatic hybrid was similar to A. kolomikta, and might have a higher capacity of cold resistance than A. chinensis. 相似文献
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8.
W. John Albery Anthony E.G. Cass Bernard P. Mangold Zhi Xin Shu 《Biosensors & bioelectronics》1990,5(5)
It is shown that an inhibited enzyme electrode, using cytochrome oxidase, will respond to H2S, HCN and azide ion. For all three inhibitors the kinetics of the inhibition and recovery processes have been analysed using the theoretical model presented previously (Albery et al., 1990a). Rearrangement of the differential equation describing inhibition and the development of the necessary software has enabled us to obtain values of the concentration of inhibitor in a matter of seconds after exposure of the sensor. The sensor will measure concentrations of H2S down to 1 ppm in the gas phase and concentrations of HCN and azide ion down to 0·4 μmol dm−3 in the solution 相似文献
9.
国产磨芋属的染色体核型报道(1) 总被引:4,自引:0,他引:4
本文报道了磨芋属(Amorphophallus Blume)六个种的染色体数目和核型,其中5个种属于首次报道。其核型公式如下: 1.滇磨芋 K(2n)=2x=26=26m.2.磨芋 K(2n)=2x=26=26m.3.攸落磨芋K(2n)=2x=26=22m(2SAT)+4sm.(2SAT).4.西盟磨芋 K(2n)=2x=26=20m+4sm+2st.5.勐海磨芋 K(2n)=2x=26=22m+4sm.6.白磨芋 K(2n)=2x=26=20m(2SAT)+6sm。 相似文献
10.
运用聚丙烯酰胺凝胶等电聚焦(PAGIF)和免疫吸引技术,研究了3个地区汉族人群的C6多态性。得到的基因频率如下:漳州市——C6*A:0.4634、C6*B:0.5000、C6*R:0.0366(C6*B2:0.0317);成都市——C6*A:0.4975,C6*B:0.4484,C6*R:0.0545(C6*B2:0.0395);哈尔滨市——C6*A:0.4708,C6*B:0.5219,C6*R:0.0073(C6*B2:0.0073)。蒙古人种的C6*A频率一般都低于0.5,高加索人种的C6*A频率一般都高于0.6。黑人则介于两者之间。蒙古人种与高加索人种的另一个区别在于前者的C6*B2频率在0.03到0.07之间,而后者几乎没有C6*B2。 相似文献