Cactus is a maternal-effect gene coding for an inhibitory protein in the Drosophila Toll signaling pathway that binds to Dorsal in the cytosol and keeps it from nuclear entry. Would you expect maternal loss-of-function mutations in Cactus to give rise to dorsalized or ventralized embryos? What about loss-of-function mutations in Decapentaplegic (Dpp)?
A) Dorsalized; dorsalized
B) Dorsalized; ventralized
C) Ventralized; dorsalized
D) Ventralized; ventralized

Question

Quizplus · Accepted Answer

Both of these mutations would result in a ventralized phenotype (similar to when Dorsal is activated in the entire embryo).

Cactus Is a Maternal-Effect Gene Coding for an Inhibitory Protein