New translation system of mRNA coding for neurotransmitter receptors using oocytes of the newt, Cynops pyrrhogaster.

Eel electroplax mRNA was injected into oocytes of newts (Cynops pyrrhogaster) and the injection induced synthesis of a nicotinic acetylcholine receptor in the oocyte membrane. The time course of the induction and dose-response relationship of the receptor were recorded electrophysiologically. The receptor responses and their developmental changes were similar to those of Xenopus oocytes injected with eel mRNA. Newt oocytes lived much longer (7-10 days) than Xenopus oocytes (3-4 days) under our experimental conditions. In non-injected newt oocytes, native transmitter receptors were not observed. In addition, newts have large oocytes (1.6-1.9 mm in diameter), into which a large amount of mRNA could be easily injected. Thus, newt oocytes may be a more useful system to translate exogenous mRNAs coding for neurotransmitter receptors than Xenopus oocytes.