Cell type-specific reduction of β tubulin isotypes synthesized in the developing gerbil organ of Corti
Cell type-specific reduction of β tubulin isotypes synthesized in the developing gerbil organ of Corti
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DOI：
10.1023/b:neur.0000005602.18713.02
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发表时间：
2003-02-01
期刊：
影响因子：
--
通讯作者：
Hallworth, R
中科院分区：
文献类型：
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作者：
Jensen-Smith, HC;Eley, J;Hallworth, R
哺乳动物中的微管蛋白 β 微管蛋白有七种同型形式，但并非所有同型都在每种细胞类型中合成。在成年柯蒂氏器官中，五种主要细胞类型中的每一种都合成不同的同种型子集。内毛细胞仅合成 β(I) 和 β(II) 微管蛋白，而外毛细胞则合成 β(I) 和 β(IV) 微管蛋白。在内柱细胞和外柱细胞中仅发现β(II)和β(IV)微管蛋白，而Deiters细胞中存在β(I)、β(II)和β(IV)微管蛋白，在柯蒂树突器官中发现β(I)、β(II)和β(III)微管蛋白。在沙鼠出生后柯蒂氏器官发育过程中，微管按照有序的时间顺序精心制作，从毛细胞开始，然后是柱细胞和 Deiters 细胞。使用β微管蛋白同种型特异性抗体，我们发现，在沙鼠耳蜗中，出生时每种细胞类型中都存在相同的三种同种型，并且在发育的异常晚期阶段，毛细胞和柱细胞中合成的同种型出现细胞类型特异性减少。在成熟的传入树突中没有检测到β微管蛋白同种型，但我们表明这是因为成熟树突中存在很少的微管。此外，我们还发现，内毛细胞中的初级纤毛（早期发育的一个特征）的存在时间比之前报道的要晚得多。这些发现首次描述了任何系统中微管蛋白同种型的发育细胞类型特异性减少。
There are seven isotypic forms of the microtubule protein beta tubulin in mammals, but not all isotypes are synthesized in every cell type. In the adult organ of Corti, each of the five major cell types synthesizes a different subset of isotypes. Inner hair cells synthesize only beta(I) and beta(II) tubulin, while outer hair cells make beta(I) and beta(IV) tubulin. Only beta(II) and beta(IV) tubulin are found in inner and outer pillar cells, while beta(I), beta(II), and beta(IV) tubulin are present in Deiters cells, and beta(I), beta(II) and beta(III) tubulin are found in organ of Corti dendrites. During post-natal organ of Corti development in the gerbil, microtubules are elaborated in an orderly temporal sequence beginning with hair cells, followed by pillar cells and Deiters cells. Using beta tubulin isotype-specific antibodies, we show that, in the gerbil cochlea, the same three isotypes are present in each cell type at birth, and that a cell type-specific reduction in the isotypes synthesized occurs in hair cells and pillar cells at an unusually late stage in development. No beta tubulin isotypes were detected in mature afferent dendrites, but we show that this is because few microtubules are present in mature dendrites. In addition, we show that primary cilia in inner hair cells, a feature of early development, persist much later than previously reported. The findings represent the first description of developmental cell type-specific reductions in tubulin isotypes in any system.