EXPRESSION OF L1 AND N-CAM CELL-ADHESION MOLECULES DURING DEVELOPMENT OF THE MOUSE OLFACTORY SYSTEM
EXPRESSION OF L1 AND N-CAM CELL-ADHESION MOLECULES DURING DEVELOPMENT OF THE MOUSE OLFACTORY SYSTEM
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DOI：
10.1016/0012-1606(89)90179-6
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发表时间：
1989-10-01
影响因子：
2.7
通讯作者：
SCHACHNER, M
中科院分区：
文献类型：
--
作者：
MIRAGALL, F;KADMON, G;SCHACHNER, M
神经粘附分子L1和N-CAM的表达已经在小鼠的胚胎和出生后早期的嗅觉系统中进行了研究，以深入了解这些分子在整个成年期保持神经元周转能力的神经结构发育过程中的功能。N-CAM在胚胎第9天的嗅板中有少量表达，而L1在胚胎第9天的嗅板中无明显表达。相反，N-CAM强烈表达的间充质下面的嗅基板。在发育中的鼻小凹，L1和N-CAM可检测到在发展中的嗅上皮，但不是在区域发展成呼吸上皮。在早期发育阶段，所谓的胚胎形式的N-CAM（E-N-CAM）的表达与N-CAM的表达相一致，而在后期发育阶段和成人中，它仅限于较少数量的感觉细胞体和轴突，这表明粘附性较低的胚胎形式是形态发生动态神经元结构的特征。此外，E-N-CAM在嗅球的肾小球中的嗅轴突和它们的靶细胞之间的接触位点处高度表达。L1和N-CAM 180，即通过与细胞骨架相互作用在细胞接触处积累的N-CAM的组分，早在第一轴突向原始嗅球延伸时就可检测到。L1在轴突过程中的整个发育过程中保持突出，无论是在与其他轴突的接触，并与ensheating细胞。与N-CAM 180相反，N-CAM 180仍然可检测到分化的感觉神经元细胞体，L1仅在这些细胞体上瞬时表达，并且在成人的初级嗅觉神经元细胞体上不再可检测到。此外，尽管在整个发育过程中L1具有与发育中和成年中枢神经系统的其他部分中所见相似的分子形式，但N-CAM，特别是N-CAM 180在所研究的所有年龄中至少部分地保留其高度唾液酸化的形式。这些观察结果表明，E-N-CAM和N-CAM 180的特征是发育活跃的结构和L1可能不仅参与神经突的生长，而且在稳定的束状轴突之间的接触和轴突和成鞘细胞之间，因为它以前被发现在周围神经系统的发展。
The expression of the neural adhesion molecules L1 and N-CAM has been studied in the embryonic and early postnatal olfactory system of the mouse in order to gain insight into the function of these molecules during development of a neural structure which retains neuronal turnover capacities throughout adulthood. N-CAM was slightly expressed and L1 was not significantly expressed in the olfactory placode on Embryonic Day 9, the earliest stage tested. Rather, N-CAM was strongly expressed in the mesenchyme underlying the olfactory placode. In the developing nasal pit, L1 and N-CAM were detectable in the developing olfactory epithelium, but not in regions developing into the respiratory epithelium. At early development stages, expression of the so-called embryonic form of N-CAM (E-N-CAM) coincides with the expression of N-CAM, whereas at later development stages and in the adult it is restricted to a smaller number of sensory cell bodies and axons, suggesting that the less adhesive embryonic form is characteristic of morphogenetically dynamic neuronal structures. Moreover, E-N-CAM is highly expressed at contact sites between olfactory axons and their target cells in the glomeruli of the olfactory bulb. L1 and N-CAM 180, the component of N-CAM that accumulates at cell contacts by interaction with the cytoskeleton are detectable as early as the first axons extend toward the primordial olfactory bulb. L1 remains prominent throughout development on axonal processes, both at contacts with other axons and with ensheating cells. Contrary to N-CAM 180 which remains detectable of differentiating sensory neuronal cell bodies, L1 is only transiently expressed on these and is no longer detectable on primary olfactory neuronal cell bodies in the adult. Furthermore, whereas throughout development L1 has a molecular form similar to that seen in other parts of the developing and adult central nervous systems, N-CAM and, in particular, N-CAM 180 retain their highly sialylated form at least partially throughout all ages studied. These observations suggest that E-N-CAM and N-CAM 180 are characteristic of developmentally active structures and L1 may not only be involved in neurite outgrowth, but also in stabilization of contacts among fasciculating axons and between axons and ensheathing cells, as it has previously been found in the developing peripheral nervous system.