Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain.
J Comp Neurol. 2013 Jun 15;521(9):2088-124. doi: 10.1002/cne.23276.
Expression patterns of Pax6, Pax7, and, to a lesser extent, Pax3 genes were analyzed by a combination of immunohistochemical techniques in the central nervous system of adult specimens of the urodele amphibian Pleurodeles waltl. Only Pax6 was found in the telencephalon, specifically the olfactory bulbs, striatum, septum, and lateral and central parts of the amygdala. In the diencephalon, Pax6 and Pax7 were distinct in the alar and basal parts, respectively, of prosomere 3. The distribution of Pax6, Pax7, and Pax3 cells correlated with the three pretectal domains. Pax7 specifically labeled cells in the dorsal mesencephalon, mainly in the optic tectum, and Pax6 cells were the only cells found in the tegmentum. Large populations of Pax7 cells occupied the rostral rhombencephalon, along with lower numbers of Pax6 and Pax3 cells. Pax6 was found in most granule cells of the cerebellum. Pax6 cells also formed a column of scattered neurons in the reticular formation and were found in the octavolateral area. The rhombencephalic ventricular zone of the alar plate expressed Pax7. Dorsal Pax7 cells and ventral Pax6 cells were found along the spinal cord. Our results show that the expression of Pax6 and Pax7 is widely maintained in the brains of adult urodeles, in contrast to the situation in other tetrapods. This discrepancy could be due to the generally pedomorphic features of urodele brains. Although the precise role of these transcription factors in adult brains remains to be determined, our findings support the idea that they may also function in adult urodeles.
通过组合使用免疫组织化学技术，我们分析了成年蝾螈 Pleurodeles waltl 中枢神经系统中 Pax6、Pax7 和在较小程度上 Pax3 基因的表达模式。只有 Pax6 存在于端脑中，具体存在于嗅球、纹状体、隔核以及杏仁核的外侧和中央部分。在间脑中，Pax6 和 Pax7 分别存在于原节 3 的翼状部和基底部。Pax6、Pax7 和 Pax3 细胞的分布与三个顶盖前区相关。Pax7 特异性标记背侧中脑的细胞，主要是视顶盖，而 Pax6 细胞是仅在脑桥中发现的细胞。大量的 Pax7 细胞占据了头侧的后脑，还有较少数量的 Pax6 和 Pax3 细胞。Pax6 存在于小脑的大多数颗粒细胞中。Pax6 细胞还在网状结构中形成了一个散在神经元的柱，并存在于八脑室区域。翼状板的后脑室区表达 Pax7。背侧的 Pax7 细胞和腹侧的 Pax6 细胞沿着脊髓分布。我们的结果表明，与其他四足动物相比，成年蝾螈大脑中广泛维持着 Pax6 和 Pax7 的表达。这种差异可能是由于蝾螈大脑的普遍幼态特征所致。尽管这些转录因子在成年大脑中的确切作用仍有待确定，但我们的发现支持了它们也可能在成年蝾螈中发挥作用的观点。
