Fractal geometry of mosaic pattern demonstrates liver regeneration is a self-similar process.
Fractal geometry of mosaic pattern demonstrates liver regeneration is a self-similar process.
复制标题
马赛克图案的分形几何表明肝脏再生是一个自相似的过程。
DOI：
10.1016/0012-1606(92)90182-g
复制
发表时间：
1992
影响因子：
2.7
通讯作者：
Iannaccone,PM
中科院分区：
文献类型：
--
作者：
Ng,YK;Iannaccone,PM
肝部分切除导致哺乳动物肝脏的代偿性、非肿瘤性生长和再生。肝脏代偿性生长可以用来检查再生组织中细胞分裂模式的各个方面。嵌合动物提供与生长无关的细胞谱系标记，并可用于遵循细胞分裂模式。先前的实验证据表明，代偿性肝生长是均匀的，没有局部的增殖中心。在这项研究中，我们将这一观察扩展到包括在再生和细胞周期控制中重要的基因，以确定新生生长中心在再生肝脏中不存在。这些基因的表达具有统一的空间分布，与嵌合体中的嵌合体模式无关。虽然这些基因可能有助于调节肝细胞的增殖，但它们似乎并不调节嵌合体中的斑块模式。有了这个证实均匀生长的信息，就有可能使用分形分析来测试肝脏再生生长的各种假想模式。分析结果表明，马赛克花纹在再生过程中没有实质性的变化。在嵌合大鼠肝脏代偿性生长期间，斑块面积和周长(同类细胞所占的面积或周长)增加，而斑块边界(相似血统细胞周围的边界)的几何复杂性没有改变。这些组织发现与之前报道的计算机生长模型是一致的，在计算机模型中，重复应用简单的决定假设均匀的生长产生复杂的镶嵌图案。他们支持这样的观点，即迭代(重复)、自相似(部分代表但不等同于整体)细胞分裂程序对于肝部分切除后肝组织的再生是足够的。迭代的、自相似的细胞分裂程序很重要，因为它们提出了一种方法，可以从少量存储的信息中高效地创建复杂的模式(或形态发生)。
Partial hepatectomy causes compensatory, nonneoplastic growth and regeneration in mammalian liver. Compensatory liver growth can be used to examine aspects of patterns of cell division in regenerating tissue. Chimeric animals provide markers of cell lineage which are independent of growth and can be used to follow cell division patterns. Previous experimental evidence suggests that compensatory liver growth is uniform, without focal centers of proliferation. In this study we have extended that observation to include genes important in regeneration and cell cycle control in order to establish that nascent growth centers are not present in regenerating liver. There is a uniform spatial distribution of expression of these genes which is not related to mosaic pattern in the chimeras. While these genes may help regulate hepatocyte proliferation they do not appear to regulate patch pattern in the chimeras. With this information confirming uniform growth it was possible to use fractal analysis to test various hypothesized patterns of regenerative growth in the liver. The results of this analysis indicate that mosaic pattern does not change substantially during the regenerative process. Patch area and perimeter (the area occupied by or perimeter around cells of like lineage) increase during compensatory liver growth in chimeric rats without alteration of the geometric complexity of patch boundaries (boundaries around cells of like lineage). These tissue findings are consistent with previously reported computer models of growth in which repetitive application of simple decisions assuming uniform growth created complex mosaic patterns. They support the notion that an iterating (repeating), self-similar (a pattern in which parts are representative of, but not identical to the whole) cell division program is sufficient for the regeneration of liver tissue following partial hepatectomy. Iterating, self-similar cell division programs are important because they suggest a way in which complex patterns (or morphogenesis) can be efficiently created from a small amount of stored information.