Ion Channels in Rana Pipiens Oocytes: Changes During Maturation and Fertilization
This chapter represents a personal view of the frog oocyte during maturation and fertilization, as seen through the eyes of an electrophysiologist. “The frog” is, in this case, the northern leopard frog, Rana pipiens. To facilitate description of the electrical properties of the oocyte and to make this chapter of broader usefulness I begin with a description of the resting membrane (voltage and resistance) and give many technical tips on making and interpreting such measurements (Section B). Next, I describe the technique of voltage clamping and include many technical tips for voltage clamping frog oocytes (Section C). Then, the maturing oocyte (metaphase I to metaphase II) is considered in some detail; first by a description of the changes in action potential propagation and ionic basis (Section D), then a voltage-clamp study of the total membrane current and its ionic basis (Section E). Methods were developed to isolate each of the three voltage-dependent currents and some properties of each are treated in Section F (C1− current), Section G (K+ current) and Section H (Na+ current). Then, I will briefly describe electrical events associated with fertilization and activation of immature and mature oocytes and will speculate on their relationship to the ion channels present at the various stages of maturation (Section I). Finally, I will speculate about mechanisms of channel regulation and will suggest further studies (Section J). Throughout this chapter, I will intersperse figures drawn from my papers in press and redrawn from our published papers. The sections called Technical Tips will describe tricks and procedures that I have found useful in making electrical recordings from Rana eggs. Most of them will be applicable to eggs of other species.
KeywordsCurrent Pulse Outward Current Voltage Clamp Mature Oocyte Tail Current
Unable to display preview. Download preview PDF.
- Jaffe, L. A. and L. C. Schlichter. 1985. Fertilization-induced ionic conductances in eggs of the frog, Rana pipiens. J. Physiol. 358: 299–319.Google Scholar
- Jaffe, L. A., R. T. Kado, and L. Muncy. 1985. Propagating potassium and chloride conductances during activation and fertilization of the egg of the frog, Rana pipiens. J. Physiol. 368: 227–242.Google Scholar
- Kado, R. T., K. Marcher, and R. Ozon. 1979. Mise en evidence d’une depolarisation de longue duree dans l’ovocyte de Xenopus laevis. C. R. Hebd. Seances Acad. Sci. Ser. D. Sci. Nat. 288: 1187–1189.Google Scholar
- Schlichter, L. C. 1989. Ionic currents underlying the action potential of Rana pipiens oocytes. Dev. Biol. (in press).Google Scholar
- Thompson, S. H. and R. W. Aldrich. 1980. Membrane potassium channels, p. 49–85. In: The Cell Surface and Neuronal Function, Vol. 6. C. W. Cotman, G. Poste and G. L. Nicolson (Eds.). Elsevier North-Holland, Amsterdam.Google Scholar
- White, M. M. and C. Miller. 1979. A voltage-gated anion channel from the electric organ of Torpedo californica. J. Biol. Chem. 254: 10161–10166.Google Scholar