Information for the dorsal--ventral pattern of the Drosophila embryo is stored as maternal mRNA

Maternal-effect mutations in 10 loci in Drosophila produce totally 'dorsalized' embryos. Injection of RNA isolated from wild-type embryos into mutants at six loci partially restores dorsal-ventral polarity. For the mutant snake, injection of poly(A)+ RNA restores a complete dorsal-ventral pattern.