Structure and Function of Glionexin, An Insect Glial Glycoprotein

神经系统中发现的一类细胞，尽管不是神经细胞本身，但被称为胶质细胞，因为它们在早期被认为是粘性胶状角色，将细胞聚集在一起。这些神经胶质细胞现在被认为对大脑正常功能的许多方面都很重要。神经胶质细胞及其相关产物参与神经系统的发育和组织的基本相互作用。昆虫被广泛用作发育的模型系统，在昆虫中，与胶质细胞相关的第一个抗原是在蟋蟀中发现的一种名为胶质连接蛋白或GX的糖蛋白化合物。其分布、空间和时间表达的特点以及初步的功能测试表明，Gx作为一种黏附/识别分子参与神经发育。本工作利用抗体探针和微序列分析，从我们拥有大量遗传信息的胚胎蟋蟀和成年果蝇中筛选遗传cDNA文库，以分离和测序编码Gx的基因。该基因的鉴定将允许对这种化合物的功能进行新的测试，这反过来将对理解在发育和再生过程中引导神经细胞生长的复杂相互作用至关重要。这项工作可能有助于更好地理解细胞黏附大分子的进化，并将对发育生物学和神经科学产生影响。

A class of cells found in the nervous system, though not nerve cells themselves is called glia, from their early presumed adhesive glue-like role to hold cells together. These glial cells are now known to be important for many aspects of normal function in the brain. Glial cells and their associated products participate in fundamental interactions which underline the development and organization of the nervous system. Insects are widely used as model system for development, and in insects the first antigen associated with glial cells was a glycoprotein compound called glionexin or GX, identified in the cricket. Features of its distribution, spatial and temporal expression, and preliminary functional tests suggested GX is involved in neural development as an adhesion/recognition molecule. This work uses antibody probes and microsequence analysis to screen genetic cDNA libraries from embryonic crickets and adult Drosophila flies, where we have a lot of genetic information, to isolate and sequence the gene encoding GX. Identification of the gene will allow new tests for function of this compound, which in turn will be important for understanding the complex interactions that guide nerve cell outgrowth during development and regeneration. The work may lead to better understanding of the evolution of cell adhesion macromolecules, and will have impact on developmental biology as well as neuroscience.