Sáez F J, Madrid J F, Aparicio R, Alonso E, Hernández F
Department of Cell Biology and Morphological Sciences, School of Medicine and Dentistry, University of the Basque Country, Vizcaya, Spain.
Tissue Cell. 2000 Aug;32(4):302-11. doi: 10.1054/tice.2000.0117.
The aim of this work was the characterization of the glycoconjugates of the premeiotic spermatogenetic cells of the testis of an urodele amphibian, Pleurodeles waltl, by means of lectins in combination with several chemical and enzymatic procedures, in order to establish the distribution of N- and O-linked oligosaccharides in these cells. In the cytoplasm of the primordial germ cells, primary and secondary spermatogonia and primary spermatocytes, a granular structure can be observed close to the nucleus. These granules contain four types of sugar chains according to their appearance during the differentiation process: 1. some oligosaccharides that are identified in all the four cell types above mentioned, which include N-linked oligosaccharides with Fuc, Gal beta1,4GlcNAc and Neu5Ac alpha2,3Gal beta1,4GlcNAc and O-linked oligosaccharides with Gal beta1,4GlcNAc and Neu5Ac alpha2,3Gal beta1,4GlcNAc; 2. other glycan chains that are not present in the primary spermatocytes (N-linked oligosaccharides with DBA-positive GalNAc, GlcNAc, and a slight amount of Neu5Ac alpha2,6Gal/GalNAc and O-linked oligosaccharides with WGA-positive GlcNAc); 3. the sugar chains that are not in the earliest step of spermatogenesis (formed by both N-linked and O-linked oligosaccharides with Glc); and 4. other that appear at the earliest and latest stages, but not in the intermediate ones, (N-linked oligosaccharides with Man and O-linked oligosaccharides with SBA- and HPA-positive GalNAc and PNA-positive Gal beta1,3GalNAc). This structure could be related with the Drosophila spectrosome and fusome, unusual cytoplasmic organelles implicated in cystic germ cell development. Data from the present work, as compared with those from mammals and other vertebrates, suggest that, although no dramatic changes in the glycosylation pattern are observed, some cell glycoconjugates are modified in a predetermined way during the early steps of the spermatogenetic differentiation process.
本研究旨在通过凝集素结合多种化学和酶促方法，对有尾两栖动物疣螈（Pleurodeles waltl）睾丸减数分裂前生精细胞的糖缀合物进行表征，以确定这些细胞中N-连接和O-连接寡糖的分布。在原始生殖细胞、初级和次级精原细胞以及初级精母细胞的细胞质中，可以观察到靠近细胞核的颗粒状结构。根据这些颗粒在分化过程中的外观，它们包含四种类型的糖链：1. 在上述所有四种细胞类型中都能鉴定出的一些寡糖，包括带有岩藻糖、β1,4-半乳糖基-N-乙酰葡糖胺、唾液酸α2,3-半乳糖基-β1,4-半乳糖基-N-乙酰葡糖胺的N-连接寡糖，以及带有β1,4-半乳糖基-N-乙酰葡糖胺和唾液酸α2,3-半乳糖基-β1,4-半乳糖基-N-乙酰葡糖胺的O-连接寡糖；2. 初级精母细胞中不存在的其他糖链（带有刀豆素A阳性N-乙酰半乳糖胺、N-乙酰葡糖胺以及少量唾液酸α2,6-半乳糖/ N-乙酰半乳糖胺的N-连接寡糖，以及带有小麦胚凝集素阳性N-乙酰葡糖胺的O-连接寡糖）；3. 不在精子发生最早阶段出现的糖链（由带有葡萄糖的N-连接和O-连接寡糖组成）；4. 出现在最早和最晚阶段，但不在中间阶段的其他糖链（带有甘露糖的N-连接寡糖，以及带有大豆凝集素和辣根过氧化物酶阳性N-乙酰半乳糖胺和花生凝集素阳性β1,3-半乳糖基-N-乙酰半乳糖胺的O-连接寡糖）。这种结构可能与果蝇的性染色体和融合体有关，这是参与囊性生殖细胞发育的异常细胞质细胞器。与哺乳动物和其他脊椎动物的研究数据相比，本研究的数据表明，尽管未观察到糖基化模式的显著变化，但在生精分化过程的早期步骤中，一些细胞糖缀合物会以预定方式发生修饰。
