Morphogenesis of the nervous system using the neurological mutants of the nematode based on molecular genetics

微管是圆柱形结构，主要由α-微管蛋白和β-微管蛋白以及几种相关蛋白组成。在包括人类在内的高等生物体中，微管具有多种重要的细胞功能，如细胞运动、细胞分裂、维持细胞形态、轴突运输和轴突生长等。微管的主要成分吕布林蛋白由多基因家族编码。我们研究了简单线虫秀丽线虫的微管蛋白亚型，因为该系统适用于衰老、细胞和分子生物学分析。许多识别不同亚型微管蛋白的单抗被鉴定出来，并用于确定它们的细胞和分子特异性。与更复杂的高等生物体一样，线虫至少有12种同工型，可以通过等电聚焦凝胶进行解析。这些亚型中的一些可被不同的单抗识别。单抗6-11B-1特异性识别机械感受性神经元，McAb2-28-33特异性识别线虫内的GABA能神经元。用免疫细胞化学方法筛选了一些运动异常的“非协调”突变体，以确定影响线虫轴突生长和引导的基因。最后，我们利用α和β微管蛋白特异性单抗直接筛选线虫微管蛋白基因表达文库，克隆线虫微管蛋白基因家族成员。α微管蛋白的核苷酸序列揭示了一种新的反式剪接信号序列。这些研究可能有助于理解高等生物中功能不同的微管形成的机制。

Microtubules are cylindrical structures, composed mainly of alpha and beta tubulin and several associated proteins. In higher organisms, including humans, microtubules serve a variety of important cellular functions, e.g. cell motility, cell division, the maintenance of cell shape, axonal transport and axon growth.The major component of microtubules, Lubulins are encoded by multigene families. We have studied tubulin isotypes in the simple nematode Caenorhabditis elegans, as the system is amenable to senelic, cellular, and molecular biological analyses. A number of monoclonal antibodies which recognize different isoforms of tubulins are identified and used to determine their cellular and molecular specificity. Like oilier complex higher organisms, the nematode has at least 12 isotypes that can be resolved on isoelctric focusing gels. Some of these isotypes are recognized by distinct monoclonal antibodies. Monoclonal antibody 6-11B-1 specifically recognizes the mechanosensory neurons, and McAb 2-28-33, is specific to GABAergic neurons in the nematode. A number of "uncoordinated" mutants with abnormal locomotion have been screened immunocytochemically, to identify genes affecting axonal growth and guidance in C. elegans. Finally, we have used the alpha and beta tubulin specific monoclonal antibodies to directly screen C. elegans _cDNA expression libraries to clone members of the tubulin gene family in C. elegans. The nucleotide sequence of an alpha tubulin reveals a novel trans-splicing signal sequence.These studies could lead to the understanding of the mechanisms by which functionally distinct microtubules are formed in higher organisms.