Germinal cells in the goldfish retina that produce rod photoreceptors.
Germinal cells in the goldfish retina that produce rod photoreceptors.
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DOI：
10.1016/0012-1606(87)90338-1
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发表时间：
1987-07
影响因子：
2.7
通讯作者：
P. Raymond;P. Rivlin
中科院分区：
文献类型：
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作者：
P. Raymond;P. Rivlin
用[3H]胸腺嘧啶核苷标记幼金鱼视网膜中的分裂细胞及其后代，并从电子显微镜放射自显影处理的连续切片中重建选定的细胞。我们的目标是表征在以前的光镜放射自显影研究中被鉴定为视杆细胞前体的细胞，并确定它们的起源和命运。(In鱼类视杆细胞的数量在胚胎后通过分散在视网膜上的视杆细胞前体细胞的增殖而增加了几倍。对取自11个视网膜的200多个标记细胞进行了检查，并对其中20个进行了完整重建。在[3H]胸苷注射后，以短间隔（1至48小时）检查一些视网膜，以研究有丝分裂活性细胞，并在较长间隔（9或14天）后检查其他视网膜，以发现标记的分裂细胞的后代的性质。先前对幼金鱼进行的胸苷研究的证据表明，注定产生杆状体的增殖细胞首先出现在内核层，随后出现在外核层，在那里它们继续分裂并产生新的杆状体（P.R. Johns，（1982）J.Neurosci.2，179）。本研究结果提供了形态学证据支持的建议，杆前体迁移从内核层到外核层，此外，表明前体密切相关，并可能指导，Müller胶质细胞的放射状突起。在用胸苷脉冲标记后第9天和第14天，标记细胞的EM放射自显影检查证实，分裂前体细胞的分化后代仅为杆状细胞。据我们所知，视杆细胞前体是脊椎动物中枢神经系统中第一个神经元生发细胞的例子，在正常情况下，它只产生一种类型的神经元。
Dividing cells and their progeny in retinae of young goldfish were labeled with [3H]thymidine, and selected cells were reconstructed from serial sections processed for electron microscopic autoradiography. Our goals were to characterize the cells that were identified as rod precursors in previous light microscopic autoradiographical studies and to determine their origin and fate. (In fish the population of rods increases several-fold postembryonically by proliferation of rod precursor cells scattered across the retina.) Over 200 labeled cells taken from 11 retinas were examined, and 20 of these were reconstructed in their entirety. Some retinas were examined at short intervals (1 to 48 hr) after [3H]thymidine injection in order to study mitotically active cells, and others were examined after longer intervals (9 or 14 days) to discover the nature of the progeny of labeled dividing cells. Previous evidence from thymidine studies in larval goldfish suggested that proliferating cells destined to produce rods appear first in the inner nuclear layer and later in the outer nuclear layer, where they continue to divide and generate new rods (P. R. Johns, (1982)J. Neurosci.2,179). The present results provide morphological evidence in support of the suggestion that rod precursors migrate from inner to outer nuclear layer and, furthermore, show that the precursors are closely associated with, and perhaps guided by, the radial processes of Müller glial cells. Examination of EM autoradiographs of labeled cells at 9 and 14 days after a pulse label with thymidine confirms that the differentiated progeny of dividing precursor cells are exclusively rods. To our knowledge, rod precursors are the first example of a neuronal germinal cell in the vertebrate central nervous system that under normal conditions produces only one type of neuron.