The morphogenesis of the head of vertebrates is a process that involves rapid growth and dynamic movements of various cell populations, including the neural crest cells (NCC). These pluripotent cells generated during neurulation have high proliferative and migratory capacity but xenobiotic agents can affect these migratory periods and cause congenital malformations. Lead (Pb) is the most common toxic metal in the environment and a potent teratogen that can affect growth and induce malformations. Despite the known toxic effects of Pb, there is a gap in knowledge about the impact of realistic concentrations of Pb at critical periods of early development. Here, we evaluated mortality, embryonic morphology, NCC migration, and the amount of Pb deposition in chicken embryos after 3 to 4 days of exposure. One of the most interesting observations in this study is that only about 34% of the injected Pb was present in the embryos after 4 days. We observed that exposure to Pb, even under low concentrations, increased mortality and the occurrence of malformations during embryonic development, especially in the cephalic region (CR). Although Pb was found widely distributed in the CR, no relation between its presence and the migration routes of cephalic NCC was observed. But the number of NCC and their migratory distance were reduced. These changes are consistent and explain the morphological anomalies described in this study, which also correlates with the morphofunctional abnormalities reported in the literature. Therefore, this study highlights the concern of exposure to low concentrations of this metal.

脊椎动物头部的形态发生是一个涉及包括神经嵴细胞 (NCC) 在内的各种细胞群的快速生长和动态运动的过程。这些在神经形成过程中产生的多能细胞具有高增殖和迁移能力，但异生物质会影响这些迁移期并导致先天性畸形。铅 (Pb) 是环境中最常见的有毒金属，也是一种会影响生长和诱发畸形的强致畸剂。尽管已知铅的毒性作用，但在早期发育的关键时期实际铅浓度的影响方面的知识仍存在空白。在这里，我们评估了鸡胚胎暴露 3 到 4 天后的死亡率、胚胎形态、NCC 迁移和铅沉积量。本研究中最有趣的观察结果之一是，4 天后胚胎中仅存在约 34% 的注射铅。我们观察到接触铅，即使在低浓度下，也会增加胚胎发育过程中的死亡率和畸形的发生，尤其是在头部区域 (CR)。尽管发现 Pb 在 CR 中广泛分布，但未观察到其存在与头侧 NCC 的迁移路线之间的关系。但是NCC的数量和它们的迁移距离减少了。这些变化是一致的，并解释了本研究中描述的形态异常，这也与文献中报道的形态功能异常相关。因此，这项研究强调了暴露于低浓度这种金属的担忧。