Supplementary Material for: Dynamic Expression and Heterogeneous Intracellular Location of En-1 during Late Mouse Embryonic Development

Engrailed-1 (En-1) is a transcription factor involved in the development of the midbrain/hindbrain during mouse early embryogenesis. Although En-1 is expressed from embryogenesis to adulthood, there has been no detailed description of its expression during late mouse embryonic development. Here we report the expression pattern of En-1 in the mouse embryo from E10.5 to the neonatal state. With immunohistochemistry we found that En-1 was expressed in the central nervous system (CNS) from E10.5 to the neonatal state, mostly restricted to the midbrain/hindbrain junction. Outside the CNS, En-1 is dynamically expressed in several neural crest-associated structures including the cranial mesenchyme, the mandibular arches, the vagus nerve, the dorsal root ganglia, the sympathetic ganglia, the somites, the heart and the cloaca. Additionally, we found that in the CNS, most of the En-1 was located in the nuclei, while outside the CNS, En-1 was mainly expressed in the cytoplasm. These findings provided additional evidence that En-1 may be involved in the development of neural crest cells.

Engrailed-1（En-1）是一种转录因子，参与小鼠早期胚胎发育过程中的中脑与后脑发育。尽管En-1的表达覆盖了从胚胎发生至成年的整个阶段，但目前尚无针对小鼠晚期胚胎发育阶段其表达模式的详细报道。本研究阐明了小鼠胚胎从E10.5至新生阶段的En-1表达谱。通过免疫组织化学实验，我们发现En-1在中枢神经系统（CNS）中从E10.5至新生阶段均有表达，且主要局限于中脑/后脑交界区域。在中枢神经系统之外，En-1在多种神经嵴相关结构中呈动态表达模式，具体包括颅间充质、下颌弓、迷走神经、背根神经节、交感神经节、体节、心脏及泄殖腔。此外，本研究还观察到，在中枢神经系统内，绝大多数En-1定位于细胞核中；而在中枢神经系统以外的区域，En-1主要表达于细胞质内。上述研究结果为En-1参与神经嵴细胞发育提供了新的实验佐证。