STRUCTURE OF PLASMODESMATA (INTERCELLULAR PLANT JUNCTIONS)

我们正在研究植物细胞间的三维结构 连接，胞间连丝（PD）。 奇沃茨基博士的实验室 博士Sosinsky网格包含厚和薄的部分， 嵌入和切片材料。 这些样本是1）叶组织2） 具有胞间连丝（PD）的纯化细胞壁和3）纯化细胞壁 用去污剂处理过的PD 索辛斯基博士收集了 3样品2的倾斜系列。 第一次重建 所以索辛斯基博士会收集更多的倾斜序列 她是 目前正在检查叶组织中的PD， 生化特征的帕金森病 在过去的一年里，我们获得了 五个倾斜系列，来自纯化细胞壁的制备物， 胞间连丝蛋白。 三个倾斜系列来自CHAPS（a 洗涤剂）处理的细胞壁，而另外两个倾斜系列是 来自未经去污剂处理的制剂。 每个人的断层扫描 计算了五个倾斜序列。 令人惊讶的是， 所有五个断层图像中的胞间连丝看起来不像基于 投影图像。 在基于两种图像的薄切片图像的模型中， 分离的胞间连丝和在叶组织中发现的胞间连丝， 胞间连丝应该类似于一个类似于 核孔复合体 在断层摄影中，我们发现了两个椭圆形的 纵向跨越细胞壁的细长结构，但不 放射状的 我们将记录完整叶片组织的倾斜序列 并因此根据这些倾斜序列按顺序计算断层图像 以评估胞间连丝结构是否为桶形， 结构中蛋白质的显著损失已经在 隔离（与项目的生物化学相协调）或 基于薄切片的模型是不正确的， 胞间连丝结构不是实心圆柱体。

We are studying the 3-dimensional structure of plant intercellular connections, the plasmodesmata (PD). Dr. Civotsky's laboratory sent Dr. Sosinsky grids containing thick and thin sections cut from embedded and sectioned material. These samples are 1) leaf tissue 2) purfied cell walls with plasmodesmata (PD) and 3) purified cell walls with PD treated with the detergent chaps. Dr. Sosinsky has collected 3 tilt series of sample 2. The first reconstruction just contained cell walls, so Dr. Sosinsky will collect more tilt series. She is presently examining the PD's in leaf tissue to compare with isolated, biochemically characterized PD's. In the past year, we have acquired five tilt series from preparations of purified cell walls containing plasmodesmota proteins. Three of the tilt series were from CHAPS (a detergent) treated cell walls while the other two tilt series were from preparations which were not detergent treated. Tomograms of each of the five tilt series were computed. Surprisingly, the plasmodesmota in all five tomograms did not look like models based on projection images. In models based on thin section images from both isolated plasmodesmota and ones found in leaf tissue, the plasmodesmota should resemble a barrel-shaped structure analogous to nuclear pore complexes. In the tomograpms, we found two elipsoidal elongated structures that span the cell wall longitudinally, but not radially. We will be recording tilt series from intact leaf tissue and consequently computing tomograms from these tilt series in order to assess if the plasmodesmota structure is barrel-shaped and a significant loss of pro teins in the structure have been lost during isolation (coordinating with the biochemistry of the project) or that the model based on thin section is incorrect and indeed, the plasmodesmota structure is not a solid cylinder.