TOMOGRAPHY OF ZIGZAG, RETIFORM AND HONEYCOMB CRISTAE IN HEART

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。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。 WhileDr.邓是RVBC的博士后，我们重建了代表两种不同晶体类型的线粒体，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。我们发现立方体区域中的空间是嵴内空间，它通过管状连接区域与线粒体内膜和外膜之间的空间相连，正如我们研究的其他类型的线粒体中所见。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。 这项工作正在继续，用狗和金丝雀的心脏线粒体。

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. 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. WhileDr. 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. This work is continuing, with heart mitochondria of dog and canary.