ELECTRON-MICROSCOPIC STUDY OF CLOSURE OF OPTIC FISSURE IN GOLDEN-HAMSTER
ELECTRON-MICROSCOPIC STUDY OF CLOSURE OF OPTIC FISSURE IN GOLDEN-HAMSTER
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DOI：
10.1002/aja.1001450402
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发表时间：
1976-01-01
影响因子：
--
通讯作者：
GEERAETS, R
中科院分区：
文献类型：
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作者：
GEERAETS, R
在哺乳动物眼睛的早期发育过程中，内陷和差异生长导致裂隙（视裂）的形成，玻璃体动脉通过该裂隙到达视杯的内部。通过电子显微镜研究了妊娠第 10 天到第 12 天的仓鼠胚胎中这条裂隙的闭合情况。仅当覆盖整个视杯壁的基底层消失时，才会发生闭合。没有发现形态学证据表明裂隙内衬基底层的破裂、相对侧表面细胞的融合以及闭合后沿壁的内边缘和外边缘的基底层的恢复的机制。虽然在之前的光学显微镜研究中已经报道了内层向裂隙中发展的人眼外翻，但在本研究中发现了外层的内翻。在反转期间，外层的细胞暂时改变了它们的方向。虽然当层返回正常位置时，大多数细胞仍保留在该层内，但一些细胞分离并退化。外层的倒置、基底层的破裂和多余细胞的变性似乎是正常闭合发生的必要事件。
During early development of the mammalian eye, invagination and differential growth result in the formation of a cleft, the optic fissure, through which the hyaloid artery reaches the interior of the optic cup. Closure of this fissure was studied by electron microscopy in hamster embryos from days 10 through 12 of gestation. Closure occurred only when and where the basal lamina, which invests the entire wall of the optic cup, had disappeared. No morphological evidence was found that indicated a mechanism for the breakdown of the basal lamina lining the fissure, the fusion of surface cells of opposing sides and restoration of the basal lamina along inner and outer margins of the wall after closure. While in previous light microscopic investigations of the developing human eye eversion of the inner layer into the fissure has been reported, an inversion of the outer layer was found in this study. During inversion cells of the outer layer temporarily changed their orientation. While most of these cells remained within the layer when it returned to its normal position, some cells became separated and degenerated. Inversion of the outer layer, breakdown of the basal lamina and degeneration of superfluous cells appear to be necessary events for a normal closure to occur.