摘要
为进一步了解河川沙塘鳢（Odontobutis potamophila）胚胎早期发育过程中孵化腺（Hatching gland，HG）的发生及其超微结构，采用透射电镜观察了河川沙塘鳢胚胎早期发育过程中心跳期、眼晶体形成期、血液循环期、眼黑色素出现期、孵化前期、初孵仔鱼期等6个不同时期的孵化腺超微结构。观察结果显示，河川沙塘鳢的孵化腺为单细胞腺体，最早可在眼晶体形成期观察到孵化腺细胞（Hatching glandc ells，HGCs），主要分布于头部腹面、头部与卵黄囊连接处及其卵黄囊前腹面；当胚胎发育至血液循环期时，HGCs不仅在形态上达到最大，数量上急剧增多，而且分布更广泛；胚胎发育进入眼黑色素出现期时，可以观察到处于不同合成时期的酶原颗粒，每个酶原颗粒外面均有膜包围，颗粒之间有明显的界限；当胚胎发育至孵化前期时，HGCs在数量上达到最多，并且可以观察到呈圆球形、直径约为0．25—1．00μm的孵化酶颗粒自HGCs顶部的开口向外分泌，这些颗粒有的以单体形式存在，有些则粘结成团；初孵仔鱼期，HGCs分泌作用已经完成，它们离开胚胎表面，移至表皮细胞下方并逐渐衰退。以上结果表明，河川沙塘鳢孵化酶颗粒有一个成熟过程，成熟的孵化酶颗粒主要通过外倾方式向卵周隙中分泌以帮助胚胎的孵化破膜。
To further investiation of the development and the uhrastructure of the hatching gland （HG） of Odontobutis potamophila during its embryonic and post-embryonic development, the hatching gland is examined with transmission electron microscopy （TEM） at heart beating stage, lens formation stage, blood circulation stage, eye pigmentation stage, pre-hatching stage and larval fish just after hatching stage of its embryonic and post-embryonic development. The hatching gland is unicellular and detected first at the stage of lens formation. The hatching gland cells （HGCs） are located in the ventral of the head, the joint region between the head and yolk sac, and the ventral of the yolk sac. At the blood circulation stage , the number and the volume of HGCs increase significantly, and HGCs spread more widely with the development of the embryo ; When the embryo reaches the eye pigmentation stage, zymogen granules at different stages are detected , and every one of the zymogen granule is wrapped by membrane, so that the limit between others can be distinguished significantly; When the embryo reaches the pre-hatching stage , the hatching enzyme granules are secreted into the perivitelline space from the top of HGCs. The secreted granules are spherical and 0.25 - 1.00 μm in diameter. Some of the secreted granules are monomer and the others get together. The hatching enzyme was dissolved in the perivitelline fluid , where it gains access to the egg envelope and digests the inner layer of egg envelope ;At the larval fish just after hatching stage, the secretion of HGCs have finished and HGCs have gradually disappeared from epidermis. The results show that the hatching enzymes of Odontobutis potamophila gradually maturated during its embryonic and post-embryonic development, and the mature hatching enzymes are excreted from the open of the HGCs to the perivitelline space for the embryo hatching.
出处
《重庆师范大学学报（自然科学版）》
CAS
2009年第4期20-24,共5页
Journal of Chongqing Normal University:Natural Science
基金
重庆市教委科研项目(No.KJ090827)
重庆市动物生物学重点实验室项目(No.0402)
重庆师范大学重点科研项目(No.08XLB001)
关键词
河川沙塘鳢
孵化腺
超微结构
Odontobutis potamophila
hatching gland
uhrastructure
