PATTERN REGULATION AND REGENERATION
PATTERN REGULATION AND REGENERATION
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DOI：
10.1098/rstb.1981.0163
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发表时间：
1981-01-01
影响因子：
6.3
通讯作者：
FRENCH, V
中科院分区：
文献类型：
--
作者：
FRENCH, V
昆虫的腿是从胚胎胸部的小区域发育而来的。在大多数昆虫中，它们在胚胎中分化，形成有功能的幼虫腿，在幼虫生活中生长和蜕皮。在果蝇中，假定的腿内陷形成成虫盘，成虫盘在幼虫期生长，但仅在蛹期分化。截肢后形成的结构，嫁接和创伤实验幼虫腿和成熟和不成熟的成虫盘的分析表明，同样的组织的位置信息和细胞行为参与的发展中的腿干扰的早期阶段（称为“调节”）和后期阶段（称为“再生”）的反应。结果表明，发展腿形成模式，根据位置信息指定的两个维度内的表皮，沿着极坐标。位置值的连续序列围绕圆周运行，并且独立序列沿着腿运行。两个规则支配着细胞在扰动后的行为。最短嵌入规则：具有不同位置值的细胞之间的相互作用引起局部生长，产生具有中间值的细胞（在圆周值的情况下通过最短路径）。远侧化规则：如果嵌入的细胞具有与相邻的预先存在的细胞相同的位置值，则新的细胞采用更远的值。这些规则将从完整的圆周产生完整的远端再生，并且可以从对称的伤口表面产生对称的再生。这种再生可能会逐渐变细（会聚）或变宽（发散）并分支成两个远端尖端，具体取决于原始伤口的范围和愈合方式。极坐标模型提供了一个简单而统一的解释，在只有本地的相互作用，实验产生的和自然发生的昆虫（和甲壳类动物和两栖动物）的四肢显示再生缺失的结构，重复的结构，并形成完整的，锥形或分支的多余物。目前尚不清楚是什么分子机制可能构成位置信息的极性图，也不清楚这种图最初是如何在早期胚胎的特定位点建立的。
Insect legs develop from small regions of the embryonic thorax. In most insects they differentiate in the embryo, forming functional larval legs, which grow and moult through larval life. InDrosophilathe presumptive legs invaginate to form imaginal discs, which grow through larval life but only differentiate in the pupal stage. Analysis of the structures formed after amputation, grafting and wounding experiments on larval legs and on mature and immature imaginal discs suggests that the same organization of positional information and cellular behaviour is involved in the response of the developing leg to disturbance at early stages (termed ‘regulation’) and at later stages (termed ‘regeneration’). The results suggest that developing legs form pattern in accordance with positional information specified in two dimensions within the epidermis, along polar coordinates. A continuous sequence of positional values runs around the circumference and an independent sequence runs down the leg. Two rules govern cellular behaviour after a disturbance.The shortest intercalation rule: interaction between cells with different positional values provokes local growth, producing cells with intermediate values (by the shortest route in the case of the circumferential values).The distalization rule: if intercalated cells have positional values identical to those of adjacent pre-existing cells then the new cells adopt a more distal value. These rules will produce a complete distal regenerate from a complete circumference and may produce a symmetrical regenerate from a symmetrical wound surface. This regenerate may taper (converge) or widen (diverge) and branch into two distal tips, depending on the extent of the original wound and the way in which it heals. The polar coordinate model provides a simple and unified interpretation, in terms of only local interactions, of a wide range of experimentally produced and naturally occurring insect (and crustacean and amphibian) limbs showing regeneration of missing structures, duplication of structures, and the formation of complete, tapering or branching supernumeraries. It is not yet clear what molecular mechanisms could underlie a polar map of positional information, nor how such a map could be initially established at a particular site in the early embryo.