Schoots A F, Evertse P A, Denucé J M
Cell Tissue Res. 1983;229(3):573-89. doi: 10.1007/BF00207699.
Around hatching, when the pike embryo sheds its acellular egg envelope, marked changes occur in the cellular covering of the embryo. This cellular covering consists of a peridermal layer and a monolayered presumptive epidermis. The periderm begins to disintegrate shortly before hatching and is sloughed off in the first posthatching period. The cellular covering produces hatching enzyme, the protease that partly dissolves the zona radiata interna of the acellular envelope. By means of the peroxidase-anti-peroxidase staining method with antibodies against hatching enzyme the cells producing this enzyme (hatching gland cells, HGCs) could be identified ultrastructurally. They are interspersed as single cells between the periderm and the presumptive epidermis. The secretory cycle of the HGC was studied. Hatching enzyme is released by an exocytotic secretory process in which multiple secretion into a "secretion vacuole" predominates. Exocytosis into surrounding intercellular spaces also occurs. These results show that the HGCs are merocrine glands. The HGC also has some "holocrine nature," however, in that only a single, massive release of its secretory product occurs. The death of the transitory HGCs in posthatching stages is characterized by condensation of the cell, formation of surface protuberances and splitting up into globular cell fragments. Eventually these fragments are ingested by epidermal cells and digested. These results lead to the conclusion that the pike HGCs degenerate by apoptosis, unlike true holocrine cells.
在孵化前后，当梭子鱼胚胎脱去无细胞卵膜时，胚胎的细胞覆盖层会发生显著变化。这种细胞覆盖层由周皮和单层假定表皮组成。周皮在孵化前不久开始解体，并在孵化后的第一个阶段脱落。细胞覆盖层产生孵化酶，即部分溶解无细胞卵膜内层放射带的蛋白酶。通过使用抗孵化酶抗体的过氧化物酶 - 抗过氧化物酶染色方法，可以在超微结构水平上识别产生这种酶的细胞（孵化腺细胞，HGCs）。它们以单个细胞的形式散布在周皮和假定表皮之间。对HGC的分泌周期进行了研究。孵化酶通过胞吐分泌过程释放，其中以多次分泌到“分泌泡”中为主。也会发生向周围细胞间隙的胞吐作用。这些结果表明HGCs是局浆分泌腺。然而，HGC也具有一些“全浆分泌性质”，因为其分泌产物仅发生一次大量释放。孵化后阶段短暂存在的HGCs的死亡特征为细胞凝聚、表面突起形成并分裂成球状细胞碎片。最终这些碎片被表皮细胞摄取并消化。这些结果得出结论，梭子鱼HGCs通过凋亡退化，这与真正的全浆分泌细胞不同。
