东方蝾螈胚胎肌节发育过程中结蛋白的出现和分布

IMMUNOCYTOCHEMICAI STUDIES ON THE APPEARANCE AND DISTRIBUTION OF DESMIN DURING MYOGENESIS IN THE EMBRYOS OF CYNOPS ORIENTALIS

本文用间接免疫荧光方法观察了结蛋白在东方蝾螈胚胎发育过程中的生成时期和分布部位。结蛋白最早出现在分期25的蝾螈胚胎中,位于长柱形的肌细胞两端。随后肌细胞中结蛋白的含量随着发育逐渐增加,呈纤维状与细胞的纵长轴平行,但仍保持着两端含量高的特点。在分期41的胚胎中观察到结蛋白与Z线结合,晚于横纹的出现。根据分布特点讨论了结蛋白在肌细胞内的分布形式与脊索的关系,并对结蛋白从纤维状转变为和Z线相结合的过程以及结蛋白、肌小节的量的积累之关系作了讨论。

Indirect immunofluorescence was used tostudy the temporal appearance and spatialdistribution of desmin during the myogenesisof the embryos of Cynops orientalis.Desminis undetectable until stage 25.In stage 25embryo,it can be seen that desmin is restric-tively distributed at both ends of columnarcells,near the boundary between two somitesand intence in the cells near by the noto-chord.From stage 26 to stage 30,the amountof desmin is increased and its distributionpattern shows little change (Plate Ⅰ,Figs.1—2).At stage 32 desmin can be detectedin the cells more distal to the notochord andforms filaments on the inside of the cell mem-brane parallel to the long axis of the cell(Plate Ⅰ,Fig.3 and 5).Desmin filamentsextend gradually from the both ends towardthe midpart of the cell (Plate Ⅰ,Fig.6 andPlate Ⅱ,Figs.7,11—13).At about stage 40the whole cell is filled with desmin filamentsand the attachment of desmin to Z line canoccassionally be detected (Plate Ⅱ,Fig.8).Desmin attached to Z line is increased at sta-ge 41 (Plate Ⅱ,Fig.9) and at stage 43 mostof the desmin is found attached to Z line(Plate Ⅱ,Fig.10).According to EM obser-vation,Z line structure can be seen in stage33 embryo (Wang),but desmin remainsin the filamental form till stage 40.Thetransference of desmin distribution patternfrom filament to Z line occurs somewhat laterthan the appearance of scattered sarcomeres. The possibility that notochord may bethe main factor which influences the spatiallocalization of desmin was analyzed.Therelationship between the transference ofdesmin from filamental to Z line attachedform and the quantitative changes of bothdesmin and sarcomere was disscussed.