Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.
J Anat. 2012 Apr;220(4):318-35. doi: 10.1111/j.1469-7580.2012.01480.x. Epub 2012 Feb 14.
Here we present a detailed study of the major events in the retinal histogenesis in a slow-developing elasmobranch species, the small-spotted catshark, during embryonic, postnatal and adult stages using classical histological and immunohistological methods, providing a complete neurochemical characterization of retinal cells. We found that the retina of the small-spotted catshark was fully differentiated prior to birth. The major developmental events in retinal cell differentiation occurred during the second third of the embryonic period. Maturational features described in the present study were first detected in the central retina and, as development progressed, they spread to the rest of the retina following a central-to-peripheral gradient. While the formation of both plexiform layers occurs simultaneously in the retina of the most common fish models, in the small-spotted catshark retina the emergence of the outer plexiform layer was delayed with respect to the inner plexiform layer. According to the expression of the markers used, retinal cell differentiation followed a vitreal-to-scleral gradient, with the exception of Müller cells that were the last cell type generated during retinogenesis. This vitreal-to-scleral progression of neural differentiation seems to be specific to slow-developing fish species.
我们使用经典的组织学和免疫组织化学方法，对一种生长缓慢的软骨鱼物种——小斑点猫鲨在胚胎期、出生后和成年期的视网膜发生过程中的主要事件进行了详细研究，为视网膜细胞提供了完整的神经化学特征描述。我们发现小斑点猫鲨的视网膜在出生前已经完全分化。视网膜细胞分化的主要发育事件发生在胚胎期的三分之二。本研究中描述的成熟特征首先在视网膜中心检测到，随着发育的进行，它们沿着从中心到周边的梯度扩散到视网膜的其余部分。虽然在最常见的鱼类模型中，两个神经丛层的形成是同时发生的，但在小斑点猫鲨的视网膜中，外神经丛层的出现相对于内神经丛层是延迟的。根据所使用的标志物的表达，视网膜细胞的分化遵循从玻璃体液到巩膜的梯度，除了 Müller 细胞是在视网膜发生过程中最后生成的细胞类型。这种从玻璃体液到巩膜的神经分化进展似乎是生长缓慢的鱼类特有的。
