很多重要生物過(guò)程,，包括心臟的正常功能，都需要一個(gè)電梯度,。人們對(duì)產(chǎn)生和維持這種電極性的機(jī)制很不了解?，F(xiàn)在，Panáková等人利用開(kāi)發(fā)用來(lái)研究發(fā)育中的斑馬魚心臟中電壓和鈣的方法,，識(shí)別出心肌平面中電耦合的一個(gè)以前未被認(rèn)識(shí)到的梯度,。
這個(gè)電梯度的出現(xiàn)取決于通過(guò)L-型鈣通道的鈣電導(dǎo)，而出人意料的是,，這個(gè)通道在生理上是由Wnt11信號(hào)作用調(diào)控的。這項(xiàng)工作表明,，胚胎心臟的電模式形成涉及細(xì)胞膜中一個(gè)重要發(fā)育信號(hào)和離子通道之間的互動(dòng),，而不是依賴于專門化的導(dǎo)電組織。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09249
Wnt11 patterns a myocardial electrical gradient through regulation of the L-type Ca2+ channel
Daniela Panáková,Andreas A. Werdich& Calum A. MacRae
Electrical gradients are critical for many biological processes, including the normal function of excitable tissues, left–right patterning, organogenesis and wound healing1, 2, 3, 4. The fundamental mechanisms that regulate the establishment and maintenance of such electrical polarities are poorly understood. Here we identify a gradient of electrical coupling across the developing ventricular myocardium using high-speed optical mapping of transmembrane potentials and calcium concentrations in the zebrafish heart. We excluded a role for differences in cellular excitability, connexin localization, tissue geometry and mechanical inputs, but in contrast we were able to demonstrate that non-canonical Wnt11 signals are required for the genesis of this myocardial electrical gradient. Although the traditional planar cell polarity pathway is not involved, we obtained evidence that Wnt11 acts to set up this gradient of electrical coupling through effects on transmembrane Ca2+ conductance mediated by the L-type calcium channel. These data reveal a previously unrecognized role for Wnt/Ca2+ signalling in establishing an electrical gradient in the plane of the developing cardiac epithelium through modulation of ion-channel function. The regulation of cellular coupling through such mechanisms may be a general property of non-canonical Wnt signals.
