Open AccessBindin is essential for fertilization in the sea urchin
Author(s) -
Gary M. Wessel,
Yuuko Wada,
Mamiko Yajima,
Masato Kiyomoto
Publication year - 2021
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2109636118
Subject(s) - gamete , sperm , human fertilization , sea urchin , biology , botany , acrosome reaction , acrosome , sexual reproduction , egg cell , evolutionary biology , microbiology and biotechnology , genetics
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.