Peirone S M, Sisto-Daneo L, Filogamo G
Department of Veterinary Morphophysiology, University of Turin, Italy.
Int J Dev Neurosci. 1990;8(1):17-31. doi: 10.1016/0736-5748(90)90020-3.
The histogenesis of iris sphincter muscle was studied in birds. Chick embryo iris "anlagen", ages from 3 days (st. 18 H.H.) to hatching, were examined. At the 4th day (st. 24 H.H.), nerve fibers were observed in the mesenchyme of the inferotemporal quadrant of the optic cup near the colobomic fissue. Among the mesenchymal cells, there were cells characterized by AChE activity, presence of desmin filaments, exhibiting ACh receptors, and ultrastructurally similar to the presumptive skeletal myoblasts. One day later (st. 27 H.H.), these myoblasts could be cultivated. The formation of myotubes began between 10 and 12 days. From 9 to 14 days, cells left the anterior epithelium of the iris to give rise to the smooth iris muscle; during this evolution some epithelial cells fused with the myotubes taking part in the histogenesis of striated muscle. The possibility of a neurogenic determination for the iris skeletal muscle is discussed.
对鸟类虹膜括约肌的组织发生进行了研究。检查了3天（哈氏18期）至孵化期的鸡胚虹膜“原基”。在第4天（哈氏24期），在视杯颞下象限靠近脉络膜裂的间充质中观察到神经纤维。在间充质细胞中，有一些细胞具有乙酰胆碱酯酶活性、结蛋白丝、乙酰胆碱受体，并且在超微结构上类似于推定的骨骼肌成肌细胞。一天后（哈氏27期），这些成肌细胞可以培养。肌管在10至12天之间开始形成。从9至14天，细胞离开虹膜前上皮，形成虹膜平滑肌；在此演变过程中，一些上皮细胞与参与横纹肌组织发生的肌管融合。讨论了虹膜骨骼肌神经源性决定的可能性。
