中文摘要
脊椎动物的视网膜起源于前脑两侧突起的视泡，视泡与覆盖的外胚层接触后内陷形成视杯，内层为预定神经视网膜（PNR），外层为预定视网膜色素上皮（PRPE）。前者将分化为三层神经细胞和六层非细胞的结构，后者只形成单层上皮。本研究利用分子生物学的方法研究PNR和PRPE的形态分化和功能分化。本研究采用TUNEL和免疫组织化学方法研究了花背蟾蜍视网膜早期发育期间PNR和PRPE中细胞凋亡和特异蛋白质GFAP，RT97和Try表达的变化。发现在PNR和PRPE中都发生细胞凋亡，而且随发育凋亡率逐渐降低，但在相同检测点PRPE中细胞凋亡率都大于PNR中的（p<0.01)。这是视网膜色素上皮变得比神经视网膜薄的一个新原因。 同时发现随发育GFAP和RT97的表达在PNR中由低到高；在PRPE中由高到低。而Try的恰恰表达相反，随发育在PRPE中逐渐增加；在PNR中逐渐降低。三种特异蛋白质变化曲线的交叉点在视泡形成后5-6小时，正是视泡与覆盖的外胚层接触前后。表明这次接触启动了外胚层对视泡的诱导，在PNR和PRPE中分别上调特异蛋白质的表达，下调非特异蛋白质的表达，促进以分子分化为基础的功能分化。
英文摘要
The retina of vertebrate retina originates from optic vesicles which begin as two bulges from the lateral walls of the prosencephalon. after connection of optic vesicles with covered epidermis, optic vesicle invaginates transforms optic cup. The inner wall of the optic cup is presumptive neural retina (PNR) and the outer wall is presumptive retinal pigment epithelium (PRPE). The former will differentiate into three cell layers and six non-cell layers, and the latter only forms one-layer, epithelium. Molecular metheds were used to study morphological and functional differentiation in PNR and in PRPE respectively in present study.In this study, TUNEL and immunohistochemistry methods were used to investigate the changes of apoptosis and expression of special proteins GFAP, RT97 and Try in PNR and in PRPE of Bufo raddei during early development respectively. We found that apoptosis occurred in both PNR and PPR, and the apoptotic rate gradually decreased and in PPR was higher than that in PNR (most p<0.01). Ii might be a new reason for explain this morphological differentiation. The expression level of GFAP and RT97 was changed from low to high in PNR, but from high to low in PRPE. Whereas the expression level of Tyr, was contrary to the expression level of GFAP and RT97. The point of intersection of these, increas
结题摘要
脊椎动物的视网膜起源于前脑两侧突起的视泡，视泡与覆盖的外胚层接触后内陷形成视杯，内层为预定神经视网膜（PNR），外层为预定视网膜色素上皮（PRPE）。前者将分化为三层神经细胞和六层非细胞的结构，后者只形成单层上皮。本研究利用分子生物学的方法研究PNR和PRPE的形态分化和功能分化。本研究采用TUNEL和免疫组织化学方法研究了花背蟾蜍视网膜早期发育期间PNR和PRPE中细胞凋亡和特异蛋白质GFAP，RT97和Try表达的变化。发现在PNR和PRPE中都发生细胞凋亡，而且随发育凋亡率逐渐降低，但在相同检测点PRPE中细胞凋亡率都大于PNR中的（p<0.01)。这是视网膜色素上皮变得比神经视网膜薄的一个新原因。 同时发现随发育GFAP和RT97的表达在PNR中由低到高；在PRPE中由高到低。而Try的恰恰表达相反，随发育在PRPE中逐渐增加；在PNR中逐渐降低。三种特异蛋白质变化曲线的交叉点在视泡形成后5-6小时，正是视泡与覆盖的外胚层接触前后。表明这次接触启动了外胚层对视泡的诱导，在PNR和PRPE中分别上调特异蛋白质的表达，下调非特异蛋白质的表达，促进以分子分化为基础的功能分化。