Bläuer M, Kohonen J, Leivonen I, Vilja P, Tuohimaa P
Department of Biomedical Sciences, University of Tampere, Finland.
Development. 1992 Aug;115(4):1079-86. doi: 10.1242/dev.115.4.1079.
Antibodies against synthetic peptides selected from the amino acid sequences of human inhibin alpha- and beta A-subunits were used to examine the distribution of inhibin subunit immunoreactivity in chicken embryos during the first week of development. Inhibin alpha-subunit immunoreactivity was localized in skeletal and smooth muscle myoblasts as well as developing cardiac muscle cells. In somites, immunostaining was seen exclusively in myotomes. The appearance of alpha-subunit immunoreactivity was correlated with myogenic differentiation; immunoreactivity was not seen in non-differentiated mesenchymal cells or in terminally differentiated adult muscle cells. In cardiac muscle, some immunopositive myocytes were seen also in the adult. In the adult heart, the Purkinje fibers were strongly immunoreactive, suggesting a possible role of the immunoreactive protein in the impulse-conducting function of these specialized cells. Inhibin alpha-subunit immunoreactivity was also seen in the visceral and parietal cells of the Bowman's capsule in both mesonephric and metanephric kidneys. In addition to mesodermal derivatives, alpha-subunit immunoreactivity was localized in neuroepithelial cells and axons in the developing central nervous system. Immunoblotting with anti-alpha(1-32) revealed two protein bands with M(r) values of 50,000 and 32,000 in cytosol samples of whole embryos under nonreducing conditions. In reduced samples an approximately 14,000 M(r) protein species was detected. Inhibin beta A-subunit immunoreactivity was detected only in chondrocytes, suggesting that the immunoreactive protein might represent a chicken homologue of the various cartilage and bone morphogenetic proteins expressed in mammals.
利用针对从人抑制素α亚基和βA亚基氨基酸序列中选取的合成肽段产生的抗体，来检测鸡胚胎发育第一周期间抑制素亚基免疫反应性的分布。抑制素α亚基免疫反应性定位于骨骼肌和平滑肌成肌细胞以及发育中的心肌细胞。在体节中，免疫染色仅见于肌节。α亚基免疫反应性的出现与肌源性分化相关；在未分化的间充质细胞或终末分化的成年肌肉细胞中未见到免疫反应性。在心肌中，在成体中也可见到一些免疫阳性的心肌细胞。在成体心脏中，浦肯野纤维有强烈的免疫反应性，提示这种免疫反应性蛋白在这些特殊细胞的冲动传导功能中可能起作用。在中肾和后肾的鲍曼囊的脏层和壁层细胞中也可见到抑制素α亚基免疫反应性。除了中胚层衍生物外，α亚基免疫反应性还定位于发育中的中枢神经系统的神经上皮细胞和轴突。用抗α(1 - 32)进行免疫印迹分析显示，在非还原条件下，整个胚胎的胞质溶胶样品中有两条分子量分别为50,000和32,000的蛋白条带。在还原样品中检测到一种分子量约为14,000的蛋白。仅在软骨细胞中检测到抑制素βA亚基免疫反应性，提示这种免疫反应性蛋白可能代表哺乳动物中表达的各种软骨和骨形态发生蛋白的鸡同源物。
