Wise Patrick A D, Vickaryous Matthew K, Russell Anthony P
Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
Anat Rec (Hoboken). 2009 Aug;292(8):1198-212. doi: 10.1002/ar.20945.
Squamates constitute a major vertebrate radiation, representing almost one-third of all known amniotes. Although speciose and morphologically diverse, they remain poorly represented in developmental studies. Here, we present an embryonic staging table of in ovo development for the basal gekkotan Eublepharis macularius (the leopard gecko) and advocate this species as a laboratory-appropriate developmental model. E. macularius, is a hardy and tractable species of relatively large body size (with concomitantly relatively large eggs and embryos), that is widely available and easy to maintain and propagate. Additionally, E. macularius displays a body plan appropriate to the study of the plesiomorphic quadrupedal condition of early pentadactylous terrestrial amniotes. Although not unexpected, it is worth noting that the morphological events characterizing limb development in E. macularius are comparable with those described for the avian Gallus gallus. Therefore, E. macularius holds great promise as a model for developmental studies focusing on pentadactyly and the formation of digits. Furthermore, it is also attractive as a developmental model because it demonstrates temperature-dependent sex determination. The staging table presented herein is based on an all-female series and represents the entire 52 day in ovo period. Overall, embryogenesis of E. macularius is similar to that of other squamates in terms of developmental stage attained at the time of oviposition, patterns of limb and pharyngeal arch development, and features of the appearance of scalation and pigmentation, indicative of a conserved developmental program.
有鳞目动物是脊椎动物中的一个主要类群，占已知羊膜动物总数的近三分之一。尽管种类繁多且形态各异，但它们在发育研究中的代表性仍然不足。在此，我们展示了基础睑虎科豹纹守宫（Eublepharis macularius）在卵内发育的胚胎分期表，并倡导将该物种作为适合实验室研究的发育模型。豹纹守宫是一种耐寒且易于处理的物种，体型相对较大（相应地，其卵和胚胎也相对较大），广泛可得且易于饲养和繁殖。此外，豹纹守宫的身体结构适合用于研究早期五指陆地羊膜动物的原始四足状态。尽管并不意外，但值得注意的是，豹纹守宫肢体发育的形态学事件与家鸡（Gallus gallus）所描述的事件相当。因此，豹纹守宫作为专注于五指形成和指发育的发育研究模型具有很大的潜力。此外，它作为发育模型也很有吸引力，因为它表现出温度依赖性性别决定。本文给出的分期表基于一个全雌性系列，涵盖了整个52天的卵内发育期。总体而言，就产卵时达到的发育阶段、肢体和咽弓发育模式以及鳞片和色素沉着出现的特征而言，豹纹守宫的胚胎发生与其他有鳞目动物相似，这表明存在一个保守的发育程序。
