TOMOGRAPHY OF ZIGZAG, RETIFORM AND HONEYCOMB CRISTAE IN HEART

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 摘要： 立方膜是对称的周期性结构，存在于各种各样的生命系统中。 有几种类型的晶体结构提出了在各种生物系统中观察到的膜阵列。 在以前的工作（邓等原生动物学）中，开发了一种模板匹配方法，使用电子显微镜间接识别晶体类型。 所研究的系统是饥饿阿米巴的线粒体。 随后，我们使用相同的材料，以确定晶体类型的电子断层重建，在计算机生成的模型体积的一个完美的晶体的适当类型进行比较。 这验证了模板匹配方法。 当邓博士在RVBC做博士后时，我们对代表两种不同晶体类型的线粒体进行了重建，双菱形和螺旋状。 计算机可视化和建模方法的广泛使用使我们不仅能够确定晶体类型（双菱形），而且还能够了解立方膜如何整合到晶体的结构中，从而深入了解它们的功能。 我们发现，在立方区域的空间是嵴内空间，这是连接到内部和外部线粒体膜之间的空间管状连接区域，如我们所研究的其他类型的线粒体。 基质材料在立方相中被狭窄地限制在膜之间，从而逆转了线粒体内大部分体积是基质材料的通常情况。 对饥饿48小时后的金丝雀心肌线粒体进行了两次双倾斜重建，以及对对照金丝雀心肌进行了一次重建。 此外，还对狗心肌线粒体进行了重建。 在来自金丝雀标本的重建中，对线粒体进行了相当多的可视化工作，特别强调线粒体具有 z字形 嵴。 Dr. Zakaria A.M. Almsherqi来自Dr. Deng的实验室访问了RVBC几天，以了解和协助可视化。 取得了良好的效果。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. ABSTRACT: Cubic membranes are symmetric, periodic structures that occur in a wide variety of living systems. There are several types of crystal structure proposed for the observed membrane arrays in a variety biological systems. In previous work (Deng, et al. Protozoology), a template matching method was developed to indirectly identify the crystal type using electron microscopy. The system studied was mitochondria of starved amoeba. Subsequently, we used the same material to determine the crystal type from electron tomographic reconstruction, in comparison to a computer-generated model volume of a perfect crystal of the appropriate type. This validated the template-matching method. While Dr. Deng was a postdoc at the RVBC, we made reconstructions of mitochondria representing examples of two different crystal types, the double-diamond and the gyroid. Extensive use of computer visualization and modeling methods enabled us to not only determine the crystal type (double-diamond any gyroid) but also to understand how the cubic membranes are integrated into the architecture of the mitochondrion, giving insights into their function. We found that the spaces in the cubic area were intracristal space, that was connected to the space between the inner and outer mitochondrial membranes by tubular connecting regions as seen in the other types of mitochondria we have studied. The matrix material was narrowly confined between the membranes in the cubic phase, thus reversing the usual situation in which most of the volume inside the mitochondria is matrix material. Two double-tilt reconstructions of canary cardiac muscle mitochondria after 48h starvation were made, as well as one reconstruction from control canary cardiac muscle. In addition, a reconstruction of mitochondria in dog heart was made. Considerable visualization work was done with mitochondria in reconstructions from the canary specimens, with special emphasis on mitochondria with zig-zag cristae. Dr. Zakaria A.M. Almsherqi from Dr. Dengs lab visited the RVBC for several days to learn about and assist with visualization. Good results were obtained.