A molecular screen for a mouse homologue of a Drosophila carbohydrate binding protein, called Gliolectin, yielded a cDNA encoding mST3GalV/GM3 synthase (CMP-NeuAc: lactosylceramide alpha2, 3-sialyltransferase). By in situ hybridization and immunohistochemistry, mST3GalV exhibits differential expression in neural and non-neural tissues. Although expressed by all neurons in the central nervous system, neuronal populations that contribute their axons to myelinated efferent projections, such as cerebellar Purkinje cells and spinal motorneurons, demonstrate the highest ST3GalV expression. When stained with anti-mST3GalV antiserum (designated CS2), subpopulations of neurons display an elaborate Golgi apparatus, frequently extending into one or more dendritic processes. The extended spatial distribution of the neuronal Golgi apparatus, particularly in spinal motorneurons, allowed the confocal immunohistochemical colocalization of mST3GalV with markers for medial/trans-Golgi but not the cis-Golgi or trans-Golgi network, consistent with previous observations suggesting that ganglioside glycosyltransferases are enriched in late Golgi compartments. Among non-neural tissues, liver and testes demonstrate cell-type specific CS2 staining. In liver, endothelial cells lining a ring of sinusoids, concentric with the central vein, express mST3GalV. Kupffer cells are also stained with CS2 antiserum but hepatocyte expression is undetectable. In the seminiferous tubules of the testes, ST3GalV is found in somatic (Leydig, Sertoli) and early germline cells (spermatogonia and primary spermatocytes); the epididymal epithelium exhibits intense ST3GalV expression. Since GM3 is a precursor for the synthesis of a- and b-series gangliosides, the range of mST3GalV/GM3 synthase expression among various cell populations indicates that certain cell types possess greater reliance on ganglioside function than others.

中文翻译：

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mST3GalV / GM3合酶的分子鉴定，组织分布和亚细胞定位。

对果蝇碳水化合物结合蛋白（称为Gliolectin）的小鼠同源物的分子筛查产生了编码mST3GalV / GM3合酶（CMP-NeuAc：乳糖基神经酰胺α2，3-唾液酸转移酶）的cDNA。通过原位杂交和免疫组织化学，mST3GalV在神经和非神经组织中表现出差异表达。尽管由中枢神经系统中的所有神经元表达，但将神经元的轴突促成髓鞘传出的投射的神经元群体，例如小脑浦肯野细胞和脊髓运动神经元，显示出最高的ST3GalV表达。当用抗mST3GalV抗血清（指定为CS2）染色时，神经元亚群显示出复杂的高尔基体，经常扩展到一个或多个树突状过程。神经元高尔基体的扩展空间分布，尤其是在脊髓运动神经元中，允许mST3GalV与内侧/反高尔基体标记共聚焦免疫共化学共定位，但不能与顺式高尔基体或反高尔基体网络共定位，这与以前的观察结果一致，表明神经节苷脂糖基转移酶在高尔基体晚期区室富集。在非神经组织中，肝脏和睾丸表现出细胞类型的特异性CS2染色。在肝脏中，与正中央静脉同心的正弦环衬里的内皮细胞表达mST3GalV。库普弗细胞也用CS2抗血清染色，但无法检测到肝细胞表达。在睾丸的生精小管中，ST3GalV存在于体细胞（Leydig，Sertoli）和早期种系细胞（精原细胞和原代精母细胞）中。附睾上皮表现出强烈的ST3GalV表达。