loss of function allele
Mad3 is an enhancer of phenotype of dpphr4
Mad3 is an enhancer of phenotype of dppe87
Mad3 is an enhancer of phenotype of dpphr56
Maternal lethal interaction with dpphr4 is due to a loss of dorsal-most fates in the embryos, demonstrated by loss of amnioserosa cells.
Mad mutations can be placed in an allelic series based on relative severity of the maternal effect enhancement of weak dpp alleles: Mad1 < Mad7 < Mad12 < Mad10 < Mad5 < Mad3 < Mad2 < Mad11 < Mad6 < Mad4 < Mad8 < Mad9.