MODEL OF PATTERN-FORMATION IN EPITHELIAL MORPHOGENESIS
MODEL OF PATTERN-FORMATION IN EPITHELIAL MORPHOGENESIS
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DOI：
10.1016/s0022-5193(87)80019-x
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发表时间：
1987-12-21
影响因子：
2
通讯作者：
ZARAISKY, AG
中科院分区：
文献类型：
--
作者：
BELINTSEV, BN;BELOUSSOV, LV;ZARAISKY, AG
形态发生中最普遍的事件之一是在最初均质的上皮片中形态极化细胞域的形成。我们研究了将这一过程视为自组织现象的可能性，该现象基于以下经过实验证明的机械化学细胞特性：（1）单个细胞的形态极化能力，被认为是细胞从非极化状态到极化状态的双稳态“全有或无”转变； (2) 通过其触点将该容量从一个电池传输到另一个电池； (3)协同细胞极化和细胞片中的切向弹性张力之间的反馈关系：细胞极化增加切向张力，而后者抑制进一步的细胞极化。我们构建了一个现象学模型来正式表达上述属性。其数学描述仅包括很少的可用于实验研究和受控变化的宏观参数。对细胞极化集体动态方案的分析表明，一些非特定参数的变化会导致细胞层形态的自发转变，并伴有对称性破缺（图灵不稳定性）。在这些条件下，可能会出现细胞极化的长程有序模式（包括六边形细胞网）或不规则的斑点结构。在片材具有固定完整尺寸且缺乏任何外部键的特殊情况下，会产生稳定的宏观状态；它对应于片材的二元细分为尺寸不变比例的偏振和非偏振细胞域。模型结论与海胆发育的形态过程、皮肤衍生物的形态发生和水螅人工诱导出芽进行了比较。
One of the most universal events in morphogenesis is the formation of domains of morphologically polarized cells in the initially homogeneous epithelial sheets. We investigate the possibility of considering this process as a phenomenon of self-organization which is based upon the following experimentally proven mechanochemical cell properties: (1) a capacity of individual cells for morphological polarization considered as a bistable "all-or-none" transition of a cell from a non-polarized to a polarized state; (2) transmissions of this capacity from one cell to another on their contacts; (3) feedback relations between co-operative cell polarization and tangenital elastic tensions in a cell sheet: cell polarization increases tangenital tensions whereas the latter inhibit further cell polarization. We have constructed a phenomenological model which formally expresses the above properties. Its mathematical description includes but few macroscopic parameters available to experimental investigation and controlled changes. The analysis of the collective dynamic regimens of cell polarization demonstrates that variations of some non-specific parameters leads to spontaneous transition in the morphology of cell layers accompanied by symmetry breaking (Turing''s instability). Under these conditions either long-range ordered patterns of cell polarization (including hexagonal cell nets) or non-regular spotted structures can emerge. In the particular case of a sheet having fixed complete dimensions and lacking any external bonds a stable macrostate is created; it corresponds to the sheet''s binary subdivision into polarized and non-polarized cell domains of size-invariant proportions. The model conclusions are compared with the morphological processes in sea-urchin development, the morphogenesis of skin derivates and artificially induced budding in hydrozoa.