心脏动脉极的形成

The Formation of Arterial Pole of the Heart

目前已发现与生心区形成心管这一过程有密切关系的关键基因和信号分子.对称的生心区后部促使心肌前体细胞形成心脏的流入区域或静脉极.最近在鸡和鼠胚胎中已经鉴定:心肌前体细胞群在咽中胚层中位于早期心管的前部.这种前部导致心脏的流出区域或动脉极处的心肌的产生.因此,脊椎动物的心脏起源于两种心肌前体细胞.这些细胞通过不同的基因程序有规律地出现.心区前部的发现对于解释突变鼠的心脏缺陷和研究人类先天性心脏病有非常重要的意义.

Some genes and signaling molecules involved in the formation of a myocardial tube from paired heartforming fields in splanchnic mesoderm have been identified. The posterior region of the paired heartforming fields subsequently contributes myocardial precursor cells to the inflow region or venous pole of the heart. Recently, a population of myocardial precursor cells in chick and mouse embryos has been identified in pharyngeal mesoderm anterior to the early heart tube. This anterior heartforming field gives rise to myocardium of the outflow region or arterial pole of the heart. The amniote heart is therefore derived from two myocardial precursor cell populations, which appear to be regulated by distinct genetic programmes.Discovery of the anterior heartforming field has important implications for the interpretation of cardiac defects in mouse mutants and for the study of human congenital heart disease.