Schmitt E A, Dowling J E
Department of Cellular and Developmental Biology, Harvard University, Cambridge, Massachusetts 02138.
J Comp Neurol. 1994 Jun 22;344(4):532-42. doi: 10.1002/cne.903440404.
Early eye morphogenesis in the zebrafish between 12 and 36 hours postfertilization was studied by light- and scanning electron microscopy. Overall, early eye morphogenesis in the zebrafish is similar to that of other vertebrates even though the optic primordia evaginate from the forebrain as solid masses of cells. After initial evagination (6-7 somite stage [SS]), the optic primordia take on a wing-like shape (8-9 SS). Subsequently, they bend ventrally and rotate slightly in an anterior direction (10-12 SS). These changes serve to bring the primordia from a horizontal to a more vertical orientation in relation to the embryonic neural axis. Invagination commences from the center of each primordium (14 SS) and progresses symmetrically out towards the periphery (14-20 SS). The choroid fissure forms by an involution along the anterior region of the eyecup (18-20 SS). By 24 hours postfertilization (pf), the eyecups are well formed. Between 24 and 36 hours pf, the eyes rotate further in relation to the axis of the embryo, and this repositions the choroid fissue to a typical ventral location by 36 hours pf. Because of the two rotations of the eye during early morphogenesis, particularly the later one, the anterior-posterior orientation of the emerging optic primordium ultimately becomes the ventral-dorsal axis of the completed eyecup.
利用光学显微镜和扫描电子显微镜研究了斑马鱼受精后12至36小时的早期眼形态发生。总体而言，斑马鱼的早期眼形态发生与其他脊椎动物相似，尽管视原基从前脑以实体细胞团的形式外翻。在最初的外翻（6 - 7体节期[SS]）之后，视原基呈现出翼状形态（8 - 9 SS）。随后，它们向腹侧弯曲并向前方轻微旋转（10 - 12 SS）。这些变化使原基相对于胚胎神经轴从水平方向转变为更垂直的方向。内陷从每个原基的中心开始（14 SS），并对称地向外围推进（14 - 20 SS）。脉络膜裂沿着眼杯的前部通过内卷形成（18 - 20 SS）。到受精后24小时（pf），眼杯已发育良好。在受精后24至36小时之间，眼睛相对于胚胎轴进一步旋转，到受精后36小时，这将脉络膜裂重新定位到典型的腹侧位置。由于早期形态发生过程中眼睛的两次旋转，特别是后期的那次旋转，新出现的视原基的前后方向最终成为完整眼杯的腹背轴。
