一种影响草履虫钾离子电导和静息膜电位的单基因突变。

A single gene mutation that affects a potassium conductance and resting membrane potential in Paramecium.

作者信息

Richard E A, Hinrichsen R D, Kung C

出版信息

J Neurogenet. 1985 Sep;2(4):239-52. doi: 10.3109/01677068509102321.

Abstract

A new mutant of Paramecium tetraurelia has been isolated with a profound defect in the regulation of membrane potential. This mutant, restless, hyperpolarizes as a potassium electrode below 8 mM external K+ whereas wild-type cells can maintain a constant resting cell potential independent of low external K+ concentration. restless dies in solutions of low K+ concentration in which wild-type can survive indefinitely. restless is not allelic to mutations that affect the depolarization-dependent Ca2+ current, the Ca2+-activated K+ current, and the Ca2+-activated Na+ current. The results suggest that restless is a new class of mutant affecting a K+ conductance hitherto not characterized genetically in Paramecium.

摘要

已分离出一种新的四膜虫突变体，其在膜电位调节方面存在严重缺陷。这种名为restless的突变体，在外部钾离子浓度低于8 mM时，会像钾电极一样发生超极化，而野生型细胞可以维持恒定的静息细胞电位，不受低外部钾离子浓度的影响。restless在低钾离子浓度溶液中死亡，而野生型可以无限期存活。restless与影响去极化依赖性钙电流、钙激活钾电流和钙激活钠电流的突变体不是等位基因。结果表明，restless是一类新的突变体，影响一种迄今在四膜虫中尚未进行遗传学表征的钾离子电导。