Machida S, Matsuoka R, Noda S, Hiratsuka E, Takagaki Y, Oana S, Furutani Y, Nakajima H, Takao A, Momma K
Department of Pediatric Cardiology, The Heart Institute of Japan, Tokyo Women's Medical University, Shinjuku, Tokyo, Japan.
Dev Dyn. 2000 Jan;217(1):37-49. doi: 10.1002/(SICI)1097-0177(200001)217:1<37::AID-DVDY4>3.0.CO;2-3.
We isolated a neonatal skeletal myosin heavy chain (MHC) cDNA clone, CV11E1, from a cDNA library of embryonic chick ventricle. At early cardiogenesis, diffuse expression of neonatal skeletal MHC mRNA was first detected in the heart tube at stage 10. During subsequent embryonic stages, the expression of the mRNA in the atrium was upregulated until shortly after birth. It then diminished, dramatically, and disappeared in the adult. On the other hand, in the ventricle, only a trace of the expression was detected throughout embryonic life and in the adult. However, transient expression of mRNA in the ventricle was observed, post-hatching. At the protein level, during the embryonic stage, the atrial myocardium was stained diffusely with monoclonal antibody 2E9, specific for chick neonatal skeletal MHC, whereas the ventricles showed weak reactivity with 2E9. At the late embryonic and newly hatched stages, 2E9-positive cells were located clearly in the subendocardial layer, and around the blood vessels of the atrial and ventricular myocardium. These results provide the first evidence that the neonatal skeletal MHC gene is expressed in developing chick hearts. This MHC appears during early cardiogenesis and is then localized in cardiac conduction cells. Dev Dyn 2000;217:37-49.
我们从胚胎期鸡心室的cDNA文库中分离出一个新生骨骼肌肌球蛋白重链（MHC）cDNA克隆CV11E1。在心脏发生早期，在第10阶段的心脏管中首次检测到新生骨骼肌MHC mRNA的弥漫性表达。在随后的胚胎阶段，心房中该mRNA的表达上调，直至出生后不久。然后其表达急剧减少，并在成体中消失。另一方面，在心室中，在整个胚胎期和成体中仅检测到微量表达。然而，在孵化后观察到心室中mRNA的短暂表达。在蛋白质水平上，在胚胎期，心房心肌被对鸡新生骨骼肌MHC具有特异性的单克隆抗体2E9弥漫性染色，而心室与2E9的反应较弱。在胚胎后期和刚孵化阶段，2E9阳性细胞清晰地位于心内膜下层以及心房和心室心肌的血管周围。这些结果提供了首个证据，表明新生骨骼肌MHC基因在发育中的鸡心脏中表达。这种MHC在心脏发生早期出现，然后定位于心脏传导细胞中。《发育动力学》2000年；217：37 - 49。
