High resolution

Module 8: Figure fertilization-induced Ca2+ oscillations

Ca2+ signalling during fertilization of a hamster oocyte.

Soon after the sperm makes contact with the oocyte at fertilization, the intracellular level of Ca2+ begins to oscillate. At the beginning, there are a series of rapid transients, before the oscillator begins to generate a regular rhythm with a periodicity of about 3 min. The series of images shown at the bottom illustrate the spatial organization of the transients that initiate at the point of sperm–oocyte fusion and then spread through the oocyte as an intracellular wave. Reproduced with permission from Miyazaki, S., Yuzaki, M., Nakada, H., Shirakawa, H., Nakanishi, S., Nakade, S., Mikoshiba, K. (1992) Block of Ca2+ wave and Ca2+ oscillation by antibody to the inositol 1,4,5-trisphosphate receptor in fertilized hamster eggs. Science, 257:251–55. Copyright (1992) American Association for the Advancement of Science; http://www.sciencemag.org; see Miyazaki et al. 1992.