The outflow tract of the heart is recruited from a novel heart-forming field
The outflow tract of the heart is recruited from a novel heart-forming field
复制标题
DOI：
10.1006/dbio.2001.0409
复制
发表时间：
2001-10-01
影响因子：
2.7
通讯作者：
Markwald, RR
中科院分区：
文献类型：
--
作者：
Mjaatvedt, CH;Nakaoka, T;Markwald, RR
如经典的描述，成对的心脏形成区域的心前中胚层在腹侧中线向前内侧迁移和融合，形成直心管的第一段。这一节段最终形成右小梁心室。从后外侧心脏形成区中胚层以顺序的方式将额外的节段添加到第一节的尾端。在这项研究中，我们报告说，最后的主要心脏段，形成心脏流出道，不遵循这种模式的胚胎发育。心脏出口，包括球茎和干，不来自成对的心脏形成领域，但分别起源于一个以前未被认识到的来源，位于前面的原始心管段的中胚层。命运映射的结果表明，标记的细胞在中胚层周围的主动脉囊和前面的原始右心室被纳入球茎和干。相反，如果在现有的右心室中标记细胞，则没有观察到掺入心脏出口。从该前中胚层区域显微切割的组织外植体能够在体外与原始右心室的外植体共培养时形成跳动的心肌。这些发现证实了另一个心脏形成场的存在。该前心脏形成区（AHF）由围绕现有心管正前方主动脉囊的中胚层组成。心脏出口胚胎起源的新概念为解释转基因动物和人类先天性心脏病中描述的各种基因表达模式和心脏缺陷提供了新的基础。(C)北京：科学出版社.
As classically described, the precardiac mesoderm of the paired heart-forming fields migrate and fuse anteriomedially in the ventral midline to form the first segment of the straight heart tube. This segment ultimately forms the right trabeculated ventricle. Additional segments are added to the caudal end of the first in a sequential fashion from the posteriolateral heart-forming field mesoderm. In this study we report that the final major heart segment, which forms the cardiac outflow tract, does not follow this pattern of embryonic development. The cardiac outlet, consisting of the corms and truncus, does not derive from the paired heart-forming fields, but originates separately from a previously unrecognized source of mesoderm located anterior to the initial primitive heart tube segment. Fate-mapping results show that cells labeled in the mesoderm surrounding the aortic sac and anterior to the primitive right ventricle are incorporated into both the corms and the truncus. Conversely, if cells are labeled in the existing right ventricle no incorporation into the cardiac outlet is observed. Tissue explants microdissected from this anterior mesoderm region are capable of forming beating cardiac muscle in vitro when cocultured with explants of the primitive right ventricle. These findings establish the presence of another heart-forming field. This anterior heart-forming field (AHF) consists of mesoderm surrounding the aortic sac immediately anterior to the existing heart tube. This new concept of the heart outlet's embryonic origin provides a new basis for explaining a variety of gene-expression patterns and cardiac defects described in both transgenic animals and human congenital heart disease. (C) 2001 Academic Press.