Guerra-Fuentes Ricardo A, Daza Juan D, Bauer Aaron M
Biology Department, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085-1699, USA.
BMC Dev Biol. 2014 Jun 30;14:29. doi: 10.1186/1471-213X-14-29.
The retinal pigmented epithelium (RPE) is a rounded shaped structure in almost all lizards. In the New World dwarf geckos, this structure shows an unusual morphology. In addition to this ocular character, we describe notable differences in the development of these geckos in comparison with available developmental staging tables for other geckos and squamate reptiles.
We identified two main patterns of development of the RPE for squamates. These patterns were mapped onto a metatree of concordant hypotheses of squamates based on molecular data. During post-ovopositional stages the representative species of sphaerodactyls exhibit a RPE layer that transforms gradually from an ovoid form into the generalized spherical form. Sphaerodactyls are the only group of squamates in which this pattern is known.
This transition might be circumstantial evidence that the accessory RPE plays a role in providing additional protection for their apomorphic concaviclivate temporal fovea. We also report the presence of conjunctival papillae in a developmental stage prior to the formation of scleral ossicles. This developmental progression is similar to that of birds and turtles.
在几乎所有蜥蜴中，视网膜色素上皮（RPE）都是圆形结构。在新大陆矮壁虎中，这种结构呈现出不同寻常的形态。除了这种眼部特征外，与其他壁虎和有鳞爬行动物现有的发育分期表相比，我们还描述了这些壁虎在发育过程中的显著差异。
我们确定了有鳞类动物RPE的两种主要发育模式。这些模式被映射到基于分子数据的有鳞类动物一致假说的元树上。在产卵后阶段，球趾虎属的代表性物种表现出一个RPE层，它从卵形逐渐转变为一般的球形。球趾虎属是已知唯一具有这种模式的有鳞类动物群。
这种转变可能是间接证据，表明附属RPE在为其特有的凹面颞侧中央凹提供额外保护方面发挥作用。我们还报告了在巩膜小骨形成之前的一个发育阶段存在结膜乳头。这种发育进程与鸟类和海龟相似。
