PRECARDIAC AREAS AND FORMATION OF TUBULAR HEART IN CHICK EMBRYO
PRECARDIAC AREAS AND FORMATION OF TUBULAR HEART IN CHICK EMBRYO
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DOI：
10.1016/0012-1606(69)90052-9
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发表时间：
1969-01-01
影响因子：
2.7
通讯作者：
DEHAAS, RL
中科院分区：
文献类型：
--
作者：
STALSBERG, H;DEHAAS, RL
中胚层和内胚层的小片段已从用胸苷-3H标记的第5阶段供体胚胎移植到未标记宿主的相应位点。这些碎片会愈合并参与受体胚胎的正常发育。已通过放射自显影确定了第12阶段管状心脏中植入细胞的分布，以提供第5阶段心前中胚层以及第12阶段心脏中的心外膜和心内膜层中的一组对应点。管状心脏被细分为 24 个定义的区域，这些区域的边界已在第 5 阶段中胚层中绘制出来。心脏形成的过程也通过中胚层的图形重建和显微解剖以及通过标记心肌外膜波谷和用氧化铁颗粒形成心管来追踪心脏形成的过程。前外膜心肌中胚层在第5阶段胚胎中组织成两个独立的区域，一个在胚胎轴的两侧，它们之间有约0.8毫米的非心源性中胚层间隙。在此阶段，心内膜前细胞被组织成大小和位置与心外膜前区域大致相似的区域，但它们更加分散。每个侧向心脏形成区域可以细分为一系列弯曲带。每个心脏形成区域的喙内侧带形成管状心脏的圆锥形组织。中部部分产生心室，每个区域的尾外侧区域提供形成心房的细胞。在心脏发生过程中，前外膜心肌中胚层表现为连贯的片层。它会压缩、拉伸、折叠和变形，但它不会失去其作为片材的完整性，也不会失去与内脏中胚层其余部分的连续性。它不会分裂成细胞或细胞簇。另一方面，心内膜细胞确实显示出在心管形成过程中以单细胞和小细胞团形式分散的一些证据。
Small fragments of mesoderm and endoderm have been transplanted from stage 5 donor embryos labeled with thymidine-3H to corresponding sites in nonlabeled hosts. These fragments heal in and participate in the normal development of the recipient embryo. The distribution of the implanted cells in the tubular heart at stage 12 has been determined by autoradiography, to provide a set of corresponding points in the stage 5 precardiac mesoderm and the epimyocardial and endocardial layers in the stage 12 heart. The tubular heart has been subdivided into 24 defined regions, and the boundaries of those regions have been mapped in the stage 5 mesoderm. The process of heart formation has also been traced through intervening stages by graphic reconstruction and microdissection of the mesoderm layer and by marking the epimyocardial troughs and forming heart tube with particles of iron oxide.The preepimyocardial mesoderm is organized in the stage 5 embryo in two separate regions, one on either side of the embryonic axis, with a gap of noncardiogenic mesoderm of about 0.8 mm between them. At this stage preendocardial cells are organized into areas generally similar in size and location to the preepimyocardial regions, but they are more widely scattered.Each lateral heart-forming region can be subdivided into a series of curved bands. The rostromedial band of each heart-forming region forms the truncoconal tissue of the tubular heart. The mid-portion gives rise to the ventricles and the caudolateral area of each region contributes the cells which form the atria.During cardiogenesis, the preepimyocardial mesoderm behaves as a coherent sheet. It condenses, stretches, folds, and deforms, but it does not lose its integrity as a sheet, nor its continuity with the rest of the layer of splanchnic mesoderm. It does not break up into cells or cell clusters. Endocardial cells, on the other hand, do show some evidence of dispersal as singlets and small groups during formation of the heart tube.