The ovule is the site of megagametogenesis and fertilization and hence is o
f central importance to sexual reproduction in seed plants. In recent years
, the ovule has become established as an excellent model system in which to
study organogenesis. Progress has been made in several aspects of ovule de
velopment: the control of ovule identity, the mechanism of primordium outgr
owth, early pattern formation and the regulation of integument morphogenesi
s.