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Updated: Oct 23, 2025

High Throughput Microinjections of Sea Urchin Zygotes
Published on: January 21, 2014
Bindin is essential for fertilization in the sea urchin
Gary M Wessel1, Yuuko Wada2, Mamiko Yajima3
1Department of Molecular and Cellular Biology & Biochemistry, Division of BioMed, Brown University, Providence, RI 02912; rhet@brown.edu.
Abstract:
Species-specific sperm-egg interactions are essential for sexual reproduction. Broadcast spawning of marine organisms is under particularly stringent conditions, since eggs released into the water column can be exposed to multiple different sperm. Bindin isolated from the sperm acrosome results in insoluble particles that cause homospecific eggs to aggregate, whereas no aggregation occurs with heterospecific eggs. Therefore, Bindin is concluded to play a critical role in fertilization, yet its function has never been tested. Here we report that Cas9-mediated inactivation of the bindin gene in a sea urchin results in perfectly normal-looking embryos, larvae, adults, and gametes in both males and females. What differed between the genotypes was that the bindin-/- sperm never fertilized an egg, functionally validating Bindin as an essential gamete interaction protein at the level of sperm-egg cell surface binding.
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