The slow block to polyspermy in the sea urchin
embryo consists of a physical barrier to further sperm
penetration into the egg. The physical barrier is the
fertilization envelope, which lifts off of the egg
surface first at the site of sperm entry.
Fertilization envelope elevation in Lytechinus pictus. Images from a movie courtesy of the Exploratorium .
Click the thumbnails to see movies of fertilization envelope production in the Pacific urchin, Lytechinus pictus (left, center) and Paracentrotus lividus.
Fertilization envelope elevation in Lytechinus pictus. Images from a movie courtesy of the Exploratorium .
Click the thumbnails to see movies of fertilization envelope production in the Pacific urchin, Lytechinus pictus (left, center) and Paracentrotus lividus.
Fertilization in Lytechinus pictus (0.8 Mb). Courtesy
of the Exporatorium.
Fertilization in Lytechinus pictus (0.4 Mb). Produced
by Ted Shinners and Jeff Hardin.
Fertilization in Paracentrotus lividus (0.4 Mb).
Courtesy of Christian Gache and Thierry Lepage,
Villefranche-sur-Mer.