Objective To evaluate whether the thermotaxis tracking model is suitable for assessing long-term memory （LTM） in the nematode Caenorhabditis elegans. Methods Animals were trained at 20℃ overnight in presence of foo...Objective To evaluate whether the thermotaxis tracking model is suitable for assessing long-term memory （LTM） in the nematode Caenorhabditis elegans. Methods Animals were trained at 20℃ overnight in presence of food. The percentage of animals performing isothermal tracking （IT） behavior was measured at different time intervals after the training. Results The percentage of animals performing IT behavior, the numbers of body bends inside and outside the training temperature, and the expression patterns of AFD and AIY neurons were similar to those in control animals at 36 and 48 h after training; whereas when extending to 60, 72, and 84 h, locomotory behavior defects were observed in the assayed animals, suggesting that this thermal tracking model is feasible for analyzing LTM at 36 and 48 h after training. Moreover, the percent-age of animals performing IT behavior was reduced at 18, 36, and 48 h after training in neuronal calcium sensor-1 gene （nsc-1） mutant animals compared with that in wild-type N2 animals. In addition, exposure to plumbum （Pb） significantly repressed the LTM at 18, 36, and 48 h after training in both wild-type N2 and ncs-1 mutant animals. Conclusion The thermotaxis tracking model is suitable for evaluating the LTM regulated by NCS-1, and can be employed for elucidating regulatory functions of specific genes or effects of stimuli on memory in C. elegans.展开更多
Calcium, an ubiquitous second messenger, plays an essential and versatile role in cellular signaling. The diverse function of calcium signals is achieved by an excess of calcium sensors. Plants possess large numbers o...Calcium, an ubiquitous second messenger, plays an essential and versatile role in cellular signaling. The diverse function of calcium signals is achieved by an excess of calcium sensors. Plants possess large numbers of calcium sensors, most of which have not been functionally characterized. To identify physiologically relevant calcium sensors in a specific cell type, we conducted a genome-wide functional survey in pollen tubes, for which spatiotemporal calcium signals are well-characterized and required for polarized tip growth. Pollen.specific members of calrnodulin （CAM）, CaM-like （CML）, calcium-dependent protein kinase （CDPK） and calcineurin B-like protein （CBL） families were tagged with green fluorescence protein （GFP） and their localization patterns and overexpression phenotypes were characterized in tobacco pollen tubes. We found that several fusion proteins showed distinct overexpression phenotypes and subcellular localization patterns. CDPK24-GFP was localized to the vegetative nucleus and the generative cell/sperms. CDPK32-GFP caused severe growth depolarization. CBL2-GFP and CBL3-GFP exhibited dynamic patterns of subcellular localization, including several endomembrane compartments, the apical plasma membrane （PM）, and cytoskeleton-like structures in pollen tubes. Their overexpression also inhibited pollen tube elongation and induced growth depolarization. These putative calcium sensors are excellent candidates for the calcium sensors responsible for the regulation of calcium homeostasis and calciumdependent tip growth and growth oscillation in pollen tubes.展开更多
背景:神经元钙传感蛋白的研究前沿和热点始终是这一领域的研究者共同关注的焦点。目的:从定量的层面探测神经元钙传感蛋白的前沿领域与研究热点。方法:以ISI的Web of Science数据库中1982至2014年363篇神经元钙传感蛋白相关文献为分析对...背景:神经元钙传感蛋白的研究前沿和热点始终是这一领域的研究者共同关注的焦点。目的:从定量的层面探测神经元钙传感蛋白的前沿领域与研究热点。方法:以ISI的Web of Science数据库中1982至2014年363篇神经元钙传感蛋白相关文献为分析对象,采用文献共被引分析方法和词频分析方法,运用CiteSpaceⅢ可视化软件绘制神经元钙传感蛋白文献共被引网络图谱和关键词共现图谱,结合突现节点文献二次检索的方法,梳理并揭示神经元钙传感蛋白的研究前沿与热点。结果与结论:神经元钙传感蛋白的研究前沿与热点是蛋白质的生理功能,研究热点转变的时间点是1994至1996年,2000年,2008年和2012年。在不同时间阶段,其研究热点也表现出一定的差异性,1992至2000年研究热点是蛋白质的结构和性质,2004至2012年主要集中于研究蛋白质的功能和作用机制。而2008至2014年研究热点是在蛋白质生理功能的研究基础上,更侧重于这一蛋白质的高级功能(如记忆)和各种疾病(如精神分裂症、肿瘤、抑郁症、老年痴呆症、神经元损伤等)的研究。神经元钙传感蛋白前沿领域与研究热点的确定,为今后的研究提供一定的参考。展开更多
文摘Objective To evaluate whether the thermotaxis tracking model is suitable for assessing long-term memory （LTM） in the nematode Caenorhabditis elegans. Methods Animals were trained at 20℃ overnight in presence of food. The percentage of animals performing isothermal tracking （IT） behavior was measured at different time intervals after the training. Results The percentage of animals performing IT behavior, the numbers of body bends inside and outside the training temperature, and the expression patterns of AFD and AIY neurons were similar to those in control animals at 36 and 48 h after training; whereas when extending to 60, 72, and 84 h, locomotory behavior defects were observed in the assayed animals, suggesting that this thermal tracking model is feasible for analyzing LTM at 36 and 48 h after training. Moreover, the percent-age of animals performing IT behavior was reduced at 18, 36, and 48 h after training in neuronal calcium sensor-1 gene （nsc-1） mutant animals compared with that in wild-type N2 animals. In addition, exposure to plumbum （Pb） significantly repressed the LTM at 18, 36, and 48 h after training in both wild-type N2 and ncs-1 mutant animals. Conclusion The thermotaxis tracking model is suitable for evaluating the LTM regulated by NCS-1, and can be employed for elucidating regulatory functions of specific genes or effects of stimuli on memory in C. elegans.
基金Supported by the State Key Basic Research and Development Plan of Chin(2007CB108704)
文摘Calcium, an ubiquitous second messenger, plays an essential and versatile role in cellular signaling. The diverse function of calcium signals is achieved by an excess of calcium sensors. Plants possess large numbers of calcium sensors, most of which have not been functionally characterized. To identify physiologically relevant calcium sensors in a specific cell type, we conducted a genome-wide functional survey in pollen tubes, for which spatiotemporal calcium signals are well-characterized and required for polarized tip growth. Pollen.specific members of calrnodulin （CAM）, CaM-like （CML）, calcium-dependent protein kinase （CDPK） and calcineurin B-like protein （CBL） families were tagged with green fluorescence protein （GFP） and their localization patterns and overexpression phenotypes were characterized in tobacco pollen tubes. We found that several fusion proteins showed distinct overexpression phenotypes and subcellular localization patterns. CDPK24-GFP was localized to the vegetative nucleus and the generative cell/sperms. CDPK32-GFP caused severe growth depolarization. CBL2-GFP and CBL3-GFP exhibited dynamic patterns of subcellular localization, including several endomembrane compartments, the apical plasma membrane （PM）, and cytoskeleton-like structures in pollen tubes. Their overexpression also inhibited pollen tube elongation and induced growth depolarization. These putative calcium sensors are excellent candidates for the calcium sensors responsible for the regulation of calcium homeostasis and calciumdependent tip growth and growth oscillation in pollen tubes.
文摘背景:神经元钙传感蛋白的研究前沿和热点始终是这一领域的研究者共同关注的焦点。目的:从定量的层面探测神经元钙传感蛋白的前沿领域与研究热点。方法:以ISI的Web of Science数据库中1982至2014年363篇神经元钙传感蛋白相关文献为分析对象,采用文献共被引分析方法和词频分析方法,运用CiteSpaceⅢ可视化软件绘制神经元钙传感蛋白文献共被引网络图谱和关键词共现图谱,结合突现节点文献二次检索的方法,梳理并揭示神经元钙传感蛋白的研究前沿与热点。结果与结论:神经元钙传感蛋白的研究前沿与热点是蛋白质的生理功能,研究热点转变的时间点是1994至1996年,2000年,2008年和2012年。在不同时间阶段,其研究热点也表现出一定的差异性,1992至2000年研究热点是蛋白质的结构和性质,2004至2012年主要集中于研究蛋白质的功能和作用机制。而2008至2014年研究热点是在蛋白质生理功能的研究基础上,更侧重于这一蛋白质的高级功能(如记忆)和各种疾病(如精神分裂症、肿瘤、抑郁症、老年痴呆症、神经元损伤等)的研究。神经元钙传感蛋白前沿领域与研究热点的确定,为今后的研究提供一定的参考。
