Kanazir S, Ruzdijic S, Vukosavic S, Ivkovic S, Milosevic A, Zecevic N, Rakic L
Department of Neurobiology and Immunology, University of Belgrade, Yugoslavia.
Brain Res Mol Brain Res. 1996 May;38(1):145-55. doi: 10.1016/0169-328x(96)00008-3.
The temporal and spatial distribution of GAP-43 mRNA in early human development, from 6 to 23 gestational weeks (g.w.), was examined by in situ hybridization histochemistry. GAP-43 mRNA was expressed as early as 6 g.w. in all regions of developing nervous system, the spinal cord, brainstem, cerebellum, diencephalic and telencephalic regions. Although the pronounced level of expression persisted during the entire examined period, the intensity of expression varied along the spatial axis over time. Analysis at the cellular level revealed that early on in development (6 g.w.) GAP-43 mRNA was expressed in the entire neuroblast population. With the onset of differentiation, at 13-23 g.w., GAP-43 mRNA expression had switched to the neurons that are in the process outgrowth. The highest level of GAP-43 mRNA expression was localized in the regions consisting of differentiating neurons, such as the cortical plate and intermediate zone of the telencephalic wall, and several delineated subcortical and thalamic nuclei. The spatial and temporal pattern of GAP-43 mRNA expression obtained suggests a possible dual role of GAP-43 in the development of the human nervous system: in the embryonic brain it could be involved in fundamental processes underlying cell proliferation; in the fetal brain its expression is specifically correlated with differentiation and the outgrowth of axons.
采用原位杂交组织化学方法，检测了妊娠6至23周早期人类发育过程中GAP - 43 mRNA的时空分布。早在妊娠6周时，GAP - 43 mRNA就在发育中的神经系统的所有区域，即脊髓、脑干、小脑、间脑和端脑区域表达。尽管在整个检测期间表达水平持续显著，但表达强度随时间沿空间轴变化。细胞水平分析显示，在发育早期（妊娠6周），GAP - 43 mRNA在整个成神经细胞群体中表达。随着分化的开始，在妊娠13至23周时，GAP - 43 mRNA的表达已切换至正在生长的神经元。GAP - 43 mRNA表达的最高水平位于由分化神经元组成的区域，如端脑壁的皮质板和中间带，以及几个明确的皮质下和丘脑核。所获得的GAP - 43 mRNA表达的时空模式表明，GAP - 43在人类神经系统发育中可能具有双重作用：在胚胎脑中，它可能参与细胞增殖的基本过程；在胎儿脑中，其表达与分化和轴突生长特异性相关。
