Insemination of rabbit eggs is associated with slow depolarization and repetitive diphasic membrane potentials.

The plasma membrane of the rabbit egg allows only one sperm to enter the egg during fertilization, but the mechanism of this block to polyspermy is unknown. Electrophysiology and in vitro fertilization techniques were employed in this study to investigate the possibility that a voltage block to polyspermy exists in rabbit eggs. Ovulated zona-intact eggs had a mean membrane potential of -71 +/- 2.1 mV (interior negative). A stereotypic response occurred 12-135 min following in vitro insemination in 19 of 40 eggs. Association of this stereotypic response with the appearance of pronuclei suggested that the electrical response was related to some interaction of gametes. This response consisted of a slow transient 8 +/- 1.5 mV depolarization upon which were superimposed up to 36 repetitive diphasic insemination potentials. Each potential consisted of a brief 2.0 +/- 0.44 mV hyperpolarization followed by a slow 2.5 +/- 0.45 mV depolarization. The small amplitude of the stereotypic response when compared with the large variation of resting potentials suggested that the response was insufficient to block polyspermy by a mechanism dependent upon the magnitude of the rabbit egg membrane potential.

[1]  N. Cross,et al.  A fast block to polyspermy in frogs mediated by changes in the membrane potential. , 1980, Developmental biology.

[2]  D. Wolf,et al.  Absence of an electrical polyspermy block in the mouse. , 1983, Developmental biology.

[3]  B. Brackett.  In vitro fertilization of rabbit ova: time sequence of events. , 1970, Fertility and sterility.

[4]  M. C. CHANG,et al.  Fertilizing Capacity of Spermatozoa deposited into the Fallopian Tubes , 1951, Nature.

[5]  L. Jaffe,et al.  Membrane potential of the unfertilized sea urchin egg. , 1978, Developmental biology.

[6]  L. Jaffe.  Fast block to polyspermy in sea urchin eggs is electrically mediated , 1976, Nature.

[7]  B. Brackett,et al.  Capacitation of rabbit spermatozoa in vitro. , 1975, Biology of reproduction.

[8]  S. Miyazaki,et al.  Fast polyspermy block and activation potential. Correlated changes during oocyte maturation of a starfish. , 1979, Developmental biology.

[9]  N. Yamashita,et al.  Ionic currents through the membrane of the mammalian oocyte and their comparison with those in the tunicate and sea urchin. , 1977, The Journal of physiology.

[10]  Y. Igusa,et al.  Fertilization potential in golden hamster eggs consists of recurring hyperpolarizations , 1981, Nature.

[11]  S. Hagiwara,et al.  The time course of cortical vesicle fusion in sea urchin eggs observed as membrane capacitance changes. , 1978, Developmental biology.

[12]  L. Holland,et al.  Electrically mediated fast polyspermy block in eggs of the marine worm, Urechis caupo , 1979, The Journal of cell biology.

[13]  R. Powers,et al.  Some electrophysiological and permeability properties of the mouse egg. , 1974, Developmental biology.

[14]  J. Overstreet,et al.  Comparison of the penetrability of the egg vestments in follicular oocytes, unfertilized and fertilized ova of the rabbit. , 1974, Developmental biology.

[15]  C. R. Austin,et al.  An investigation of polyspermy in the rat and rabbit. , 1953, Australian journal of biological sciences.

[16]  L. Zamboni,et al.  Electron microscopic studies on rabbit ova: II. The penetrated tubal ovum , 1966 .