Results obtained by Costa et al. in a new study of a maize mutation indicate that some of the mechanisms that determine cell fate during animal development also act in some plants (see ). The recessive lethal mutation globby1-1 (glo1-1) is characterised by an aberrant globular embryo and endosperm morphology. In their detailed developmental analysis of glo1-1 mutant seeds, Costa and co-workers report that embryonic pattern formation is impaired, and that glo1-1 mutants have aberrant nuclear and cell proliferation in the early syncytial endosperm and cellular endosperm, respectively. Local disruptions in the organisation of the basal endosperm transfer layer (BETL)that followed on from these early abnormalities, they suggest, occurred because BETL cells differentiate in a lineage-dependent manner – a common mechanism for cell-fate specification in animals such as Drosophila that is, however, rare in plants.
