TOMOGRAPHY OF ZIGZAG, RETIFORM AND HONEYCOMB CRISTAE IN HEART

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。立方膜是一种对称的周期性结构，广泛存在于各种生物系统中。对于各种生物系统中观察到的膜阵列，有几种类型的晶体结构被提出。在以前的工作中(邓等人原生动物学)，发展了一种模板匹配法，利用电子显微镜间接鉴定晶体类型。研究的系统是饥饿的阿米巴的线粒体。随后，我们使用相同的材料从电子断层重建中确定晶体类型，并与计算机生成的适当类型的完美晶体的模型体积进行比较。这验证了模板匹配方法的有效性。在此期间。邓是RVBC的博士后，我们重建了线粒体，代表了两种不同晶体类型的例子，双钻石和陀螺。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(双钻石任何陀螺体)，而且还能够了解立方膜如何整合到线粒体的结构中，从而深入了解它们的功能。我们发现，立方体区域内的间隙是颈内间隙，与我们研究的其他类型的线粒体一样，它通过管状连接区连接到线粒体内外膜之间的间隙。基质材料被狭窄地限制在立方相中的膜之间，从而扭转了线粒体内大部分体积是基质材料的通常情况。这项工作仍在继续，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.