PO GLYCOPROTEIN MESSENGER-RNA DISTRIBUTION IN MYELIN-FORMING SCHWANN-CELLS OF THE DEVELOPING RAT TRIGEMINAL GANGLION
PO GLYCOPROTEIN MESSENGER-RNA DISTRIBUTION IN MYELIN-FORMING SCHWANN-CELLS OF THE DEVELOPING RAT TRIGEMINAL GANGLION
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DOI：
10.1007/bf01188043
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发表时间：
1990-10-01
期刊：
影响因子：
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通讯作者：
WEBSTER, HD
中科院分区：
文献类型：
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作者：
LAMPERTH, L;MANUELIDIS, L;WEBSTER, HD
将生物素化的Po cDNA原位杂交于第2天、第7天、第15天、第30天和成年大鼠三叉神经节的醛固定振动体切片。采用抗体夹心法检测镍增强辣根过氧化物酶（HRP）的杂交。在四氧化二锇中固定后，切片在乙醇中脱水并包埋在epon中。在每个年龄，用一些振动体切片计数hrp阳性和hrp阴性的髓鞘形成雪旺细胞。第2天、第7天、第15天、第30天和成年大鼠神经节中hrp阳性髓磷脂形成雪旺细胞的比例分别为31.56%、47%、12%和3%。在2日龄大鼠的神经节切片上，通过光镜和电镜观察，在雪旺细胞核周区颗粒状（粗糙）内质网（RER）的轮廓上发现过氧化物酶反应产物定位的Po mRNA，这些颗粒状（粗糙）内质网已形成2至3个致密的髓鞘片。髓鞘较厚的细胞的细胞质中过氧化物酶沉积物较大，数量较多。第7天，部分雪旺细胞外中轴突较长；这些中间轴突和细胞表面之间的细胞质通常含有丰富的酶标染色的内质网。在第7天和第15天的神经节切片中，发现了更多的反应产物。在每个形成髓鞘的雪旺细胞中，其数量通常与新形成髓鞘的大小成正比。在这些年龄，髓鞘节段外表面均可见HRP沉积，其分布与内质网的分布一致。随后，在第30天和成人中，含有反应产物的雪旺细胞减少，每个雪旺细胞中都有较少的反应产物，表明在髓鞘形成的后期，雪旺细胞中存在较低水平的Po mRNA。成人中Po含量最低，这可能反映了髓鞘维持过程中Po转换所需的水平。
A biotinylated Po cDNA was hybridized in situ to aldehyde-fixed vibratome sections of trigeminal ganglia from day 2, day 7, day 15, day 30 and adult rats. Nickel-enhanced horseradish peroxidase (HRP) was used in an antibody sandwich method to detect hybridization. After postfixation in osmium tetroxide, the sections were dehydrated in ethanol and embedded in epon. At each age, some vibratome sections were used to count the HRP-positive and HRP-negative myelin-forming Schwann cells. The percentage of HRP-positive myelin-forming Schwann cells in ganglia from day 2, 7, 15, 30, and adult rats were 31, 56%, 47%, 12% and 3%. In sections of ganglia from 2-day-old rats, studied by light and electron microscopy, peroxidase reaction product localizing hybridized Po mRNA was found on profiles of granular (rough) endoplasmic reticulum (RER) in perinuclear regions of Schwann cells which had formed two to three compact myelin lamellae. Peroxidase deposits were larger and more numerous in the cytoplasm of cells with thicker myelin sheaths. At day 7, some Schwann cells had long external mesaxons; the cytoplasm between these mesaxons and the cell surface often contained abundant HRP-stained profiles of RER. In sections from day 7 and day 15 ganglia, substantially more reaction product was found. In each myelin-forming Schwann cell, the amount was generally proportional to the size of the newly formed myelin sheath. HRP deposits were observed all along the outer surfaces of myelin segments at these ages, and their distribution corresponded to that of the RER. Later on, at day 30 and in the adult, fewer Schwann cells contained reaction product, and there was less in each one, indicating that lower levels of Po mRNA are present in Schwann cells during later stages of myelination. The lowest levels were seen in adults and may reflect those needed for Po turnover during myelin sheath maintenance.