Raymond P A
Department of Anatomy & Cell Biology, University of Michigan Medical School, Ann Arbor 48109-0616.
Ciba Found Symp. 1991;160:171-86; discussion 186-91. doi: 10.1002/9780470514122.ch9.
The neural retina in teleost fish can regenerate after surgical or neurotoxic destruction. Whereas in amphibians the retina regenerates by transdifferentiation of pigmented retinal epithelial cells, in goldfish (Carassius auratus) the source of regenerated retinal cells is a population of scattered proliferating cells located in the outer nuclear layer within the differentiated retina. These proliferating cells are modified neuroepithelial cells termed 'rod precursors' because in the intact retina they produce only rod photoreceptor cells and do so continuously, inserting new rods into the growing adult retina. Although rod precursors normally exhibit a restricted developmental fate they appear not to be committed to the rod lineage. When retinal neurons are destroyed, rod precursors cease producing rods and give rise to clusters of primitive neuroepithelial cells which divide vigorously and reconstitute the retina in an orderly temporal pattern that mimics the process of normal development. Only after production of cones and other retinal neurons has ceased do rod precursors again appear and resume the generation of rods. We conclude that rod precursors respond to local cues in their environment that regulate the differentiation and choice of cell fate by their progeny.
硬骨鱼的神经视网膜在手术或神经毒性破坏后能够再生。在两栖动物中，视网膜通过色素性视网膜上皮细胞的转分化进行再生，而在金鱼（Carassius auratus）中，再生视网膜细胞的来源是位于已分化视网膜内核层中的一群分散的增殖细胞。这些增殖细胞是经过修饰的神经上皮细胞，被称为“视杆前体细胞”，因为在完整的视网膜中，它们仅持续产生视杆光感受器细胞，并将新的视杆细胞插入不断生长的成年视网膜中。尽管视杆前体细胞通常表现出有限的发育命运，但它们似乎并未完全确定为视杆细胞谱系。当视网膜神经元被破坏时，视杆前体细胞停止产生视杆细胞，并产生成群的原始神经上皮细胞，这些细胞会剧烈分裂，并以模仿正常发育过程的有序时间模式重新构建视网膜。只有在锥体细胞和其他视网膜神经元的产生停止后，视杆前体细胞才会再次出现并恢复视杆细胞的产生。我们得出结论，视杆前体细胞对其环境中的局部信号做出反应，这些信号通过其子代调节细胞命运的分化和选择。
