Studies On Immunocytochemistry And Ultrastructure Of Hatching Gland Cells From Penaeus Chinensis

Hatching enzyme (HE), synthesized in hatching gland cells (HGCs), plays vital roles in animal hatching. Immunocytochemical techniques employing anti-GST-UVS.2 antiserum, prepared from Xenopus HE and with specificity to Penaeus chinensis HE, were first used to investigate the differentiation and variability of hatching gland cells (HGCs) in the hatching process of embryos of marine shrimp, Penaeus chinensis, in this study. HGCs with immunoreactivity to anti-GST-UVS.2 antiserum were identified, for the first time, in shrimp embryos during hatchingprocess.Immunocytochemical staining results showed that: HE-positive immunoreactivity is really specific to Penaeus chinensis HE, and its appearance and disappearance are closely correlated with the hatching process of Penaeus chinensis; Penaeus chinensis HGCs, first appeared in embryos 15 hours before hatching and disappeared 20 hours after hatching, were also a transient type of cells, with an existence period of 35 hours; the back portion of Penaeus chinensis embryo is probably the initial position of HE secretion, and likely to be the main position of HE secretion as well; the appearance of HGCs is in a synchronous mode from places all over the embryos, and their disappearance is also in a synchronous mode; the number of HGCs increased gradually along with embryo development process and reached a maximum number at hatching. Contrarily, the number of HGCs decreased gradually after hatching, and HGCs disappeared 20 hours after hatching. However, the intensity of HE-positive reaction was almost at the same level at the period of HGCs'presence. Therefore, it can concluded that marine shrimp Penaeus chinensis HGCs, as a transient type of cells, first appeared in embryos 15 hours before hatching and disappeared in embryos 20 hours after hatching, and with distinguished patterns of appearance, disappearance and distribution in embryos. All these findings indicate that HGC is a kind of transient type of cells, which first appeared all over the body of embryo 15 hours before hatching, and disappeared 20 hours after hatching.By the ultrastructure study of the marine shrimp embryos, we find some muscle fibril and more yelk distributing the whole embryo; HGCs which form in ovum and rotundity posited in the surface of the body and some HGCs develop the micro-floccus structure; there are abnormity salient on the HGC surface before secreting zymogen granules, whereafter secreting there will develop vacuole in the HGC; the nucleolus of HGC is relatively larger than common cells and organelles such as endoplasm, ribosome and mitochondria are very abundantly, as magnify the HGC, we find more nuclear pore complexes; there are much electron dencity unequal aymogen granules of roundish in 0.3μm ~0.5μm distributed in the HGCs.