Altering fish embryos with XXXX : an essential step toward successful cryopreservation.

@entity1 @entity70565 @entity3392
Fish populations are globally threatened by overharvesting and habitat degradation. The ability to bank fish embryos by cryopreservation could be crucial for preserving species diversity, for aquaculture (allowing circannual fish farming), and for managing fish models used in @entity1 biomedical research. However, no nonmammalian embryo has ever been successfully cryopreserved. For fish, low membrane permeability prevents cryoprotectants from entering the yolk to prevent cryodamage. Here, we present evidence of a membrane mechanism hindering cryopreservation of fish and propose a novel solution to this obstacle. @entity3392 ( @entity3392 ) embryos have rectifying membranes that allow water to leave but not to reenter readily. This feature may be an evolutionary trait that allows freshwater embryos to grow in hypoosmotic environments without osmoregulatory organs. However, this trait may also prevent successful fish embryo cryopreservation because both water and cryoprotectants must move into and out of cells. As a solution, we injected @entity3392 embryos with mRNA for the @entity70565 water channel protein and demonstrated increased membrane permeability to water and to a cryoprotectant. Modeling indicates that sufficient cryoprotectant enters @entity70565 -expressing @entity3392 embryos to allow cryopreservation.
