Figure 1.

Model of the developmental pattern of the leaf (A) and the stamen (B). (A) Lamina outgrowth occurs at the junction of the adaxial and abaxial domains in the leaf. (B) In anther development, the adaxial-abaxial polarity is rearranged. The boundary regions between the adaxial and abaxial domains outgrow and differentiate into pollen sacs. In the filament, a radially symmetrical structure is formed by abaxialization. The adaxial and abaxial domains are shown in red and blue, respectively. Double-headed arrows represent the axis of adaxial-abaxial polarity. Green arrows indicate the direction of formation of the outgrowth. ab, abaxial side; ad, adaxial side.