Spitzer R H, Downing S W, Koch E A
Cell Tissue Res. 1979 Mar 19;197(2):235-55. doi: 10.1007/BF00233917.
Light- and electron-microscopic autoradiography were used to obtain a coordinated metabolic-morphologic view of some of the events of cellular differentiation that occur across the epidermis of the Pacific hagfish (Eptatretus stoutii) and which enable this animal to secrete copious amounts of mucus. As judged by epidermal incorporation of [3H]-thymidine in vivo, about 98% of DNA replication is confined to the basal three layers of the total of 6--8 layers of cells. Small mucous cells (SMC), the most numerous of the three major cell types involved in mucigenesis, show in vitro and in vivo radioincorporation profiles of [3H]-L-lysine and [3H]-D-glucosamine which differ markedly from those of [3H]-L-fucose and [3H]-D-galactose. Time-course incorporation profiles (mean silver grains/cell and percentage of cells with at least one cluster of silver grains) of [3H]-L-lysine and [3H]-D-glucosamine not only reflected the metabolic activities of cell renewal and differentiation in basally-located cells but also the high mucigenic activity in cells near the epidermal surface. By contrast, [3H]-L-fucose and [3H]-D-galactose were mainly incorporated by the more mature SMC in juxtanuclear regions near Golgi complexes and newly formed secretory vesicles. The intensity of [3H]-fucose labeling appeared proportional to the intensity of histochemical staining of the apical cytoplasm. The prominent capsule, within SMC in basal and lateral regions, which arises from a tight intermingling of tonofilaments, appears to restrict secretory vesicles to apical regions while the cell progressively differentiates and migrates to the epidermal surface. The other mucigenic cell types, large mucous cells and thread cells, each show distinctive differentiation and radioincorporation patterns.
利用光镜和电镜放射自显影技术，对太平洋盲鳗（Eptatretus stoutii）表皮发生的一些细胞分化事件进行了代谢 - 形态学的综合观察，这些事件使这种动物能够分泌大量黏液。通过体内表皮对[³H] - 胸腺嘧啶核苷的掺入情况判断，在总共6 - 8层细胞中，约98%的DNA复制局限于基部的三层细胞。小黏液细胞（SMC）是参与黏液生成的三种主要细胞类型中数量最多的，其在体外和体内对[³H] - L - 赖氨酸和[³H] - D - 葡糖胺的放射性掺入情况与[³H] - L - 岩藻糖和[³H] - D - 半乳糖明显不同。[³H] - L - 赖氨酸和[³H] - D - 葡糖胺的时间进程掺入情况（平均银粒数/细胞以及至少有一簇银粒的细胞百分比）不仅反映了基部细胞的细胞更新和分化的代谢活性，还反映了表皮表面附近细胞的高黏液生成活性。相比之下，[³H] - L - 岩藻糖和[³H] - D - 半乳糖主要由靠近高尔基体复合体和新形成的分泌小泡的近核区域中更成熟的SMC掺入。[³H] - 岩藻糖标记的强度似乎与顶端细胞质的组织化学染色强度成正比。基部和侧面区域的SMC内由张力丝紧密交织形成的突出囊泡，似乎在细胞逐渐分化并迁移到表皮表面时将分泌小泡限制在顶端区域。其他黏液生成细胞类型，大黏液细胞和丝状细胞，各自表现出独特的分化和放射性掺入模式。
