Toyota N, Shimada Y
J Cell Biol. 1981 Nov;91(2 Pt 1):497-504. doi: 10.1083/jcb.91.2.497.
The differentiation of troponin (TN) in cardiac and skeletal muscles of chicken embryos was studied by indirect immunofluorescence microscopy. Serial sections of embryos were stained with antibodies specific to TN components (TN-T, -I, and -C) from adult chicken cardiac and skeletal muscles. Cardiac muscle began to be stained with antibodies raised against cardiac TN components in embryos after stage 10 (Hamburger and Hamilton numbering, 1951, J. Morphol. 88:49-92). It reacted also with antiskeletal TN-I from stage 10 to hatching. Skeletal muscle was stained with antibodies raised against skeletal TN components after stage 14. It also reacted with anticardiac TN-T and C from stage C from stage 14 to hatching. It is concluded that, during embryonic development, cardiac muscle synthesizes TN-T and C that possess cardiac-type antigenicity and TN-I that has antigenic determinants similar to those present in cardiac as well as in skeletal muscles. Embryonic skeletal muscle synthesizes TN-I that possesses antigenicity for skeletal muscle and TN-T and C which share the antigenicities for both cardiac and skeletal muscles. Thus, in the development of cardiac and skeletal muscles, a process occurs in which the fiber changes its genomic programming: it ceases synthesis of the TN components that are immunologically indistinguishable from one another and synthesizes only tissue-type specific proteins after hatching.
通过间接免疫荧光显微镜研究了鸡胚心肌和骨骼肌中肌钙蛋白（TN）的分化情况。用成年鸡心肌和骨骼肌TN成分（TN-T、-I和-C）的特异性抗体对胚胎的连续切片进行染色。在第10阶段（汉堡和汉密尔顿编号，1951年，《形态学杂志》88:49 - 92）之后的胚胎中，心肌开始被针对心脏TN成分产生的抗体染色。从第10阶段到孵化期，它也与抗骨骼肌TN-I发生反应。在第14阶段之后，骨骼肌被针对骨骼肌TN成分产生的抗体染色。从第14阶段到孵化期，它也与抗心脏TN-T和-C发生反应。得出的结论是，在胚胎发育过程中：心肌合成具有心脏型抗原性的TN-T和-C以及具有与心脏和骨骼肌中存在的抗原决定簇相似的TN-I；胚胎骨骼肌合成具有骨骼肌抗原性的TN-I以及对心脏和骨骼肌都具有抗原性的TN-T和-C。因此，在心肌和骨骼肌的发育过程中，发生了一个纤维改变其基因组编程的过程：它停止合成在免疫学上无法区分的TN成分，并且在孵化后仅合成组织类型特异性蛋白质。
