Pabst O, Herbrand H, Arnold H H
Department of Cell and Molecular Biology, Technical University of Braunschweig, Spielmannstrasse 7, 38106, Braunschweig, Germany.
Mech Dev. 1998 Apr;73(1):85-93. doi: 10.1016/s0925-4773(98)00035-5.
Nkx homeobox transcription factors are expressed in diverse embryonic cells and presumably control cell-type specification and morphogenetic events. Nkx2-9 is a novel family member of NK2 genes which lacks the conserved TN-domain found in all hitherto known murine Nkx2 genes. The prominent expression of Nkx2-9 in ventral brain and neural tube structures defines a subset of neuronal cells along the entire neuraxis. During embryonic development, Nkx2-9-expressing cells shift from the presumptive floor plate into a more dorsolateral position of the neuroectoderm and later become limited to the ventricular zone. Nkx2-9 expression overlaps with that of Nkx2-2 but is generally broader. While initially Nkx2-9 is expressed in close proximity to sonic hedgehog, its expression domain clearly segregates from sonic hedgehog at later developmental stages. The dynamic expression pattern of Nkx2-9 in ventral domains of the CNS is consistent with a possible role in the specification of a distinct subset of neurons.
Nkx 同源框转录因子在多种胚胎细胞中表达，可能控制细胞类型的特化和形态发生事件。Nkx2-9 是 NK2 基因的一个新家族成员，它缺乏在所有迄今已知的小鼠 Nkx2 基因中都存在的保守 TN 结构域。Nkx2-9 在腹侧脑和神经管结构中的显著表达定义了沿整个神经轴的神经元细胞亚群。在胚胎发育过程中，表达 Nkx2-9 的细胞从假定的底板转移到神经外胚层更背外侧的位置，随后局限于脑室区。Nkx2-9 的表达与 Nkx2-2 的表达重叠，但通常更广泛。虽然最初 Nkx2-9 在靠近音猬因子的位置表达，但其表达域在后期发育阶段与音猬因子明显分离。Nkx2-9 在中枢神经系统腹侧区域的动态表达模式与它在特定神经元亚群特化中可能发挥的作用一致。
