Biology Department, College of Science, Taibah University, Medina, Saudi Arabia.
Zoology Department, Faculty of Science, Fayoum University, Fayoum, Egypt.
J Exp Zool B Mol Dev Evol. 2020 Jul;334(5):294-310. doi: 10.1002/jez.b.22951. Epub 2020 May 14.
Studying reptilian embryonic development provides answers to many questions related to the development of tetrapods. Reptilian skin has been recently considered in studies at the evo-devo level. The lizard epidermis has to be shed periodically. At the embryonic level, contention exists regarding the first layers to appear, whether the oberhautchen or the clear layer, and whether the shedding complex develops before hatching. Geckos exhibit diverse morphologies independently evolved multiple times within the clade, such as subdigital pad lamellae. Here we investigate the embryonic development of Tarentola mauritanica and establishing its embryonic table. Primarily we follow the development of the integument. This is a closely related species to Tarentola annularis and it is crucial to investigate whether it has the same derived digital condition of claw regression. Eleven embryonic stages are described according to the external morphological characteristics of the embryos. Interestingly, the oviposition stage appears earlier than its close relative T. annularis, and the total incubation time is less. We also describe skin development, adding clear evidence to the debate on the development of the shedding complex, which we found is developed before hatching. We describe one layer of periderm and the clear layer as the first embryonic epidermal layers. Generally, our results show the genus Tarentola to have the advantage of being a unique taxon, easily breed at the laboratory, with multiple clutches per year, and with an earlier stage at oviposition. That could be a model animal for embryonic development and experimental embryology studies.
研究爬行动物胚胎发育为许多与四足动物发育相关的问题提供了答案。最近，在进化发育水平的研究中，爬行动物的皮肤受到了关注。蜥蜴的表皮需要定期蜕皮。在胚胎水平上，关于最先出现的是 oberhautchen 还是透明层，以及蜕皮复合物是否在孵化前发育，存在争议。壁虎在其进化枝内独立进化出了多种形态，如亚指垫鳞片。在这里，我们研究了 Tarentola mauritanica 的胚胎发育并建立了其胚胎表。我们主要跟踪皮肤的发育。这是 Tarentola annularis 的近缘种，研究它是否具有相同的爪退化的衍生数字条件至关重要。根据胚胎的外部形态特征，描述了 11 个胚胎阶段。有趣的是，产卵阶段比其近亲 T. annularis 更早出现，总孵化时间更短。我们还描述了皮肤的发育，为关于蜕皮复合物发育的争论提供了明确的证据，我们发现蜕皮复合物是在孵化前发育的。我们描述了一层表皮和透明层作为最初的胚胎表皮层。总的来说，我们的结果表明 Tarentola 属具有作为独特分类群的优势，易于在实验室繁殖，每年有多个卵群，产卵阶段更早。它可能是胚胎发育和实验胚胎学研究的模型动物。
