Different roles of gamma- and beta-actin in neuronal functions

Lack of cytoplasmic beta-actin gene (Actb) leads to early embryonic lethality in mice, however targeted editing of Actb coding sequence by introducing five point mutations to encode cytoplasmic gamma-actin protein does not affect mouse viability. These mice with beta to gamma actin replacement (Actbc-g mice) develop normally and show no detectable phenotypes at young age, despite complete lack of beta-actin protein. Here we investigated the effect of the replacement of beta-actin with gamma-actin in the brain and the retina --- the tissue where these two cytoplasmic actin isoforms predominate.