Marcus R C, Gale N W, Morrison M E, Mason C A, Yancopoulos G D
Department of Pathology, Center for Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, 630 W. 168th Street, New York, New York, 10032, USA.
Dev Biol. 1996 Dec 15;180(2):786-9. doi: 10.1006/dbio.1996.0347.
The Eph family of receptor tyrosine kinases and their ligands can be divided into two specificity subclasses: the Eck-related receptors and their GPI-anchored ligands, and the Elk-related receptors and their transmembrane ligands. Previous reports demonstrated that Eck- and Elk-related receptors in the retina distribute in high temporal-low nasal and high ventral-low dorsal gradients, respectively. While others have focused on complementary ligand gradients in the retinal axon target, the tectum, we report that ligands from each subclass also distribute in gradients opposing those of their corresponding receptors within the retina itself. Moreover, ligand gradients in the retina precede ganglion cell genesis. These results support an intraretinal role for Eph family members in addition to their previously proposed role in the development of retinotectal topography. The distinct distributions of Eph family members suggest that each subclass specifies positional information along independent retinal axes.
受体酪氨酸激酶的Eph家族及其配体可分为两个特异性亚类：Eck相关受体及其糖基磷脂酰肌醇（GPI）锚定配体，以及Elk相关受体及其跨膜配体。先前的报道表明，视网膜中的Eck相关受体和Elk相关受体分别以高颞侧-低鼻侧和高腹侧-低背侧梯度分布。虽然其他人关注的是视网膜轴突靶标顶盖中互补的配体梯度，但我们报告称，每个亚类的配体在视网膜自身内部也以与其相应受体相反的梯度分布。此外，视网膜中的配体梯度先于神经节细胞的发生。这些结果支持了Eph家族成员在视网膜内的作用，此外它们先前被认为在视网膜顶盖拓扑结构的发育中起作用。Eph家族成员的不同分布表明，每个亚类沿着独立的视网膜轴指定位置信息。
