Wave of free calcium at fertilization in the sea urchin egg visualized with fura-2
✍ Scribed by Hafner, Mathias ;Petzelt, Christian ;Nobiling, Rainer ;Pawley, James B. ;Kramp, Douglas ;Schatten, Gerald
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 913 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0886-1544
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✦ Synopsis
A wave front of increased free calcium traversing the egg at fertilization is demonstrated in the sea urchin Lytechinus pictus. The use of the fluorescent calcium chelator fura-2 in combination with low-light-level TV microscopy and image processing allows the visualization of the Ca2+ wave front with high spatial and temporal resolution. Such a wave is demonstrated as increased fluorescence after an excitation of 340-nm wavelength and as the reciprocal image in form of a reduced fluorescence when excited at 380 nm. The band-like appearance of the wave resembles the Ca2+ wave described for larger eggs of other species. In a dispennic egg the high resolution of the system used allows us to recognize two waves of Ca2+ originating from the respective points of sperm entry.