Jansen H G, Sanyal S
J Comp Neurol. 1984 Mar 20;224(1):71-84. doi: 10.1002/cne.902240107.
In the retina of mice homozygous for the retinal degeneration slow (rds) gene, receptor outer segments failed to develop and typical disc structures were never observed. However, cilia surrounded by a plasma membrane were regularly present. At the time when outer segments grew in the normal retina, the optic ventricle in the mutant showed an accumulation of membrane-bound vesicles of varying size and density. The vesicles declined in frequency at later stages of degeneration. After initial growth, the inner segments in the mutant retina remained stunted but maintained their morphological differentiation, including the ciliary structures. Their number declined with loss of visual cells. In the mutant retina development of synapses, between the receptor cells and the processes of the horizontal cells and the bipolar cell dendrites, followed in normal sequence. Formation of spherule terminals of the rods, with one triad synapse, and of pedicle terminals of the cones, with multiple triad synapses, was recorded in the same way as in the normal retina. With loss of visual cells in the mutant retina, some of the profiles of the surviving spherule terminals showed an increased occurrence of two, three, or more synaptic sites. This growth resulted from enlargement and branching of the ribbons and sprouting from the postsynaptic elements. Similar changes were not observed in the pedicle terminals. The pigment epithelial cells in the mutant mice appeared initially normal, but phagolysosomal structures were absent. However, various inclusion bodies appeared within the pigment epithelial cells following degenerative changes in the retina. In some places, the basal infoldings deepened their furrows while thinning the cytoplasmic part of the epithelium. Failure to form the outer segments and the subsequent lysis of the visual cells appear to be the primary effects of the rds gene, whereas the synaptic growth in the sperule terminals and the changes in the pigment epithelium appear to be consequential to those defects.
在视网膜变性慢（rds）基因纯合的小鼠视网膜中，受体外节未能发育，从未观察到典型的盘状结构。然而，被质膜包围的纤毛却正常存在。在正常视网膜外节生长的时候，突变体的视泡中出现了大小和密度各异的膜结合小泡的积累。这些小泡在变性后期频率下降。初始生长后，突变体视网膜中的内节仍然发育不良，但保持了它们的形态分化，包括睫状结构。它们的数量随着视觉细胞的丧失而减少。在突变体视网膜中，受体细胞与水平细胞的突起以及双极细胞树突之间的突触发育遵循正常顺序。与正常视网膜一样，记录到了具有一个三联突触的视杆细胞小球终末和具有多个三联突触的视锥细胞足状终末的形成。随着突变体视网膜中视觉细胞的丧失，一些存活的小球终末的轮廓显示出两个、三个或更多突触位点的出现频率增加。这种生长是由带状物的扩大和分支以及突触后元件的出芽导致的。在足状终末未观察到类似变化。突变体小鼠的色素上皮细胞最初看起来正常，但没有吞噬溶酶体结构。然而，随着视网膜的退行性变化，色素上皮细胞内出现了各种包涵体。在某些地方，基底褶皱加深了它们的沟，同时使上皮细胞的细胞质部分变薄。未能形成外节以及随后视觉细胞的溶解似乎是rds基因的主要作用，而小球终末中的突触生长和色素上皮的变化似乎是这些缺陷的结果。
