Novel phenotypes and developmental arrest in early embryo specific mutantsof maize

Embryo specific (emb) mutants exhibit aberrant embryo development without d eleterious effects on endosperm development. We have analyzed five emb muta nts of maize, which, based on their developmental profiles can be divided i nto two groups: mutants arrested at early stages and mutants with novel phe notypes. The members of the first group resemble wild-type proembryos and n ever reach other developmental stages. In the second group the tube-shaped mutants emb*-8522 and emb*-8535 completely lack apical-basal differentiatio n, while in mutant emb*-8516 a second embryo-like structure arises from the suspensor. The five emb mutations analyzed are non-allelic and two of the mutations are very likely caused by insertion of the transposon mutator, op ening the door for their molecular analysis.