Pollen Development in Maize
Pollen development in maize includes asymmetric cell divisions to form cells with two very different fates; either parietal, anther cell layers or sporogenous cells that will undergo meiosis. Differentiation of anther cells eventually produces four cell layers, including the innermost tapetal cell layer. Tapetal cells are ephemeral, but they are crucial to the normal development of the male gametophyte, or pollen grain, within the anther locule. Our work has included the study of normal pollen development as well as the analysis of several male-sterile mutants in which normal pollen development is disrupted. These mutants include msca1 (male sterile converted anther) which lacks sporophytic cells, ms23, in which the tapetal layer undergoes an additional division without normal differentiation, and ms25, in which tapetal cells accumulate abnormally high levels of lipid bodies.