A love SEP that determines cross-species sperm-egg compatibility, by Pauli and colleagues
Herberg, S., Gert, K. R., Schleiffer, A., & Pauli, A. (2018). The Ly6/uPAR protein Bouncer is necessary and sufficient for species-specific fertilization. 361(6406), 1029–1033. https://doi.org/10.1126/science.aat7113
In Finding Nemo, Nemo's loving and monogamous parents Marlin and Coral jealously guard their brood of eggs, which will give rise to Amphiprion offspring, with no paternity disputes. But have you ever wondered, in a non-Pixar real world marine environment, where spawning occurs in a very public fashion, how do eggs ensure that they are fertilized with the correct sperm?
Herberg et al. discover in this dazzling paper in Science that a SEP, Bouncer, resides in the oocyte membrane where it mediates binding to sperm and facilitates fertilization. When ectopically expressed, it can even induce cross-species fertilization between Merdaka and zebrafish. Whether Bouncer and its orthologues can has sufficient diversity to "barcode" the oocytes in a species-specific manner is unclear. I look forward to developments in the biology of this love potion no. 9 SEP.