Key-notes on Neural Induction
key notes
1. Neural Induction
1.2. Genetic redundancy
The BMP patterning system that underlies neural induction in vertebrates is notable for extensive redundancy in gene function that has made a loss-of-function approach problematic: mutations that eliminate only one of these inhibitors tend to have relatively mild phenotypes on their own. For example, a loss-of-function mutation in Zebrafish chordin (the chordino mutant) causes only a reduction in the size of the neural plate while mouse embryos that lack just one the BMP antagonists, chordin or noggin, by knockout mutations have a relatively normal nervous system. However, the full potential of these antagonists became apparent when several of them are removed at the same time. A complete loss of neural tissue is observed when all three BMP antagonists, chordin, follistatin and noggin, are simultaneously targeted using morpholinos, both in Xenopus and in Zebrafish.