焦点粘连作为压力传感器 - Mary Beckerle P3
本视频由科普中国和生物医学大讲堂出品
Mary Beckerle (University of Utah) Part 3: Focal Adhesions as Stress Sensors
In the third segment of my seminar, I address a new frontier in cell biology, that is how cells respond to mechanical information. Cells and tissues are exposed to physical forces in vivo and excessive mechanical stress leads to a variety of pathological consequences. I describe a system for exposing cells to controlled mechanical stress and discuss the stretch response. We have discovered that the focal adhesion protein, zyxin, is exquisitely sensitive to mechanical stimulation and is required for the ability of cells to reinforce the actin cytoskeleton when challenged by exposure to cyclic stretch. See more at http://www.ibiology.org
Photoreceptors and Image Processing Part 1A - Jeremy Nathans
本视频由科普中国和生物医学大讲堂出品
Jeremy Nathans (Johns Hopkins) Part 1A: Photoreceptors and Image Processing
In this set of lectures, Jeremy Nathans explores the molecular mechanisms within the retina that mediate the first steps in vision. The first lecture focuses on the structure of the light sensing receptors, the intracellular signals that are triggered by light absorption, and the ways in which the retina extracts information from a complex scene. See more at http://www.ibioseminars.org
Photoreceptors and Image Processing Part 1B - Jeremy Nathans
本视频由科普中国和生物医学大讲堂出品
Jeremy Nathans (Johns Hopkins) Part 1B: Photoreceptors and Image Processing
In this set of lectures, Jeremy Nathans explores the molecular mechanisms within the retina that mediate the first steps in vision. The first lecture focuses on the structure of the light sensing receptors, the intracellular signals that are triggered by light absorption, and the ways in which the retina extracts information from a complex scene. See more at http://www.ibioseminars.org
Stability of Morphogen Gradients & Movement of Molecules
In my second lecture I describe experiments using EGFP tagged Bicoid to follow Bcd gradient establishment in living embryos, and to test various aspects of the simple model. Despite continuous synthesis of new Bcd protein at the anterior end of the egg, we find that the concentration of Bcd in nuclei at any given point along the anterior posterior axis is constant over time and is reproducible from embryo to the next. This reproducibility means that the gradient is sufficiently robust to provide positional information and thus can accurately direct gene activities. One the other hand, quantitative imaging experiments point to several features of the gradient that are hard to explain - how target genes activated by Bcd distinguish relatively subtle differences in low concentrations, and how Bcd molecules move from the anterior site of their synthesis to the site of their transcriptional activity. See more at http://www.ibioseminars.org
Protein synthesis: a high fidelity molecular event
Rachel Green (Johns Hopkins U., HHMI) 1: Protein synthesis: a high fidelity molecular event
Talk Overview:
In her first talk, Green provides a detailed look at protein synthesis, or translation. Translation is the process by which nucleotides, the “language” of DNA and RNA, are translated into amino acids, the “language” of proteins. Green begins by describing the components needed for translation; mRNA, tRNA, ribosomes, and the initiation, elongation, and termination factors. She then explains the roles of these players in ensuring accuracy during the initiation, elongation, termination and recycling steps of the translation process. By comparing translation in bacteria and eukaryotes, Green explains that it is possible to determine which components and steps are highly conserved and predate the divergence of different kingdoms on the tree of life, and which are more recent adaptations.
Green’s second talk focuses on work from her lab investigating how ribosomes detect defective mRNAs and trigger events leading to the degradation of the bad RNA and the incompletely translated protein product and to the recycling of the ribosome components. Working in yeast and using a number of biochemical and genetic techniques, Green’s lab showed that the protein Dom34 is critical for facilitating ribosome release from the short mRNAs that result from mRNA cleavage. Experiments showed that Dom34-mediated rescue of ribosomes from short mRNAs is an essential process for cell survival in higher eukaryotes.
Speaker Biography:
Rachel Green received her BS in chemistry from the University of Michigan. She then moved to Harvard to pursue her PhD in the lab of Jack Szostak where she worked on designing catalytic RNA molecules and investigating their implications for the evolution of life. As a post-doctoral fellow at the University of California, Santa Cruz, Green began to study how the ribosome translates mRNA to protein with such accuracy.
Currently, Green is a Professor of Molecular Biology and Genetics at the Johns Hopkins School of Medicine and an Investigator of the Howard Hughes Medical Institute. Research in her lab continues to focus on the ribosome and factors involved in the fidelity of eukaryotic and prokaryotic translation.
Green is the recipient of a Johns Hopkins University School of Medicine Graduate Teaching Award as well as the recipient for numerous awards for her research. She was elected to the National Academy of Sciences in 2012.
PureBlu™ Hoechst 33342 Nuclear Staining Dye for Live Cells - A Fast Approach to Staining Nuclei
This brief tutorial demonstrates the use of the PureBlu Hoechst 33342 Dye with the ZOE™ Fluorescent Cell Imager for routine nuclear staining in fluorescence microscopy and cell imaging applications.
The eolution of collective behavior集体行为的进化
互动产生网络,互动网络是如何演变的？新的路径如何形成？跟随戈登对12000种蚂蚁探索、开发、繁殖研究的脚步，看看互动网络应对环境挑战的发展吧。
Molecular Chaperones in the Eukayotic Cell
为什么组织特异性？为什么这些有毒蛋白质？为什么不协在神经元的反应？为什么伴侣不是百分之.......霍华德休斯医学研究所Art Horwich在真核细胞中的伴侣蛋白分子的讲座中将一一为您解答。
Connectomics: Seeking neural circuit motifs
人类的大脑是非常复杂的，更大的结构和功能的多样性比其他器官和这种复杂性是确定的按某人的经验和某人的基因。 在报告1部分，Lichtman解释了如何映射的关系在大脑（神经连接）可能会导致一个更好的理解大脑的功能。
Neuromuscular Connectomics
Part 2：使用不同颜色的转基因小鼠, 荧光标记的蛋白质在每个神经元（“彩虹”老鼠）, Lichtman和他的同事们能够遵循的形成, 在小鼠发育过程中的神经肌肉接头的破坏。这项工作是2部分的重点。