Sequential programs of retinoic acid synthesis in the myocardial and epicardial layers of the developing avian heart
Sequential programs of retinoic acid synthesis in the myocardial and epicardial layers of the developing avian heart
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DOI：
10.1006/dbio.1999.9588
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发表时间：
2000-03-01
影响因子：
2.7
通讯作者：
Rosenthal, N
中科院分区：
文献类型：
--
作者：
Xavier-Neto, J;Shapiro, MD;Rosenthal, N
内源性模式的维甲酸（RA）信号转导在鸟类心脏形态的特点是本地化的关键RA合成酶，RALDH 2，在心脏发育过程中表现出双相模式的表达。RALDH 2免疫反应最初是明显的后阶段5-6胚胎的亨森结，随后在体节和不分段的近轴和侧板中胚层重叠心房前体的阶段9胚胎的心原性板。后壁心肌中RALDH 2的初始合成与AMHC 1基因的激活相一致，AMHC 1基因是流入心脏节段的RA反应标记物。然后RALDH 2合成的波在后到前的方向上扫过心肌，在第13阶段到达流出道，然后从心肌层消失。RALDH 2表达的第二阶段，在第18阶段在前心外膜器官中开始，持续存在于到第24阶段完全包裹心脏的心脏外膜细胞中。早期限制RALDH 2表达的后心板，重叠RA诱导的基因激活，提供了证据，承诺后禽心脏段的本地化生产的RA，而随后RALDH 2表达专门在迁移性心外膜表明的作用，在心室扩张和形态发生的基础心肌组织的形态。(C)北京大学出版社.
Endogenous patterns of retinoic acid (RA) signaling in avian cardiac morphogenesis were characterized by localized expression of a key RA-synthetic enzyme, RALDH2, which displayed a biphasic pattern during heart development. RALDH2 immunoreactivity was initially apparent posterior to Hensen's node of stage 5-6 embryos and subsequently in somites and unsegmented paraxial and lateral plate mesoderm overlapping atrial precursors in the cardiogenic plate of stage 9- embryos. Initial RALDH2 synthesis in the posterior myocardium coincided with activation of the AMHC1 gene, a RA-responsive marker of inflow heart segments. A wave of RALDH2 synthesis then swept the myocardium in a posterior-to-anterior direction, reaching the outflow tract by stage 13, then fading from the myocardial layer. The second phase of RALDH2 expression, initiated at stage 18 in the proepicardial organ, persisted in mi,oratory epicardial cells that completely enveloped the heart by stage 24. Early restriction of RALDH2 expression to the posterior cardiogenic plate, overlapping RA-inducible gene activation, provides evidence for commitment of posterior avian heart segments by localized production of RA, whereas subsequent RALDH2 expression exclusively in the migratory epicardium suggests a role for the morphogen in ventricular expansion and morphogenesis of underlying myocardial tissues. (C) 2000 Academic Press.