In situ localization of PrMADS3
transcripts in developing SCBs, PCBs, and DSBs. a, Differentiating SCB.
Expression in the group of cells initiating ovuliferous scale primordia
is shown by arrowheads (magnification ×42). b, Cross-section of
differentiating SCB. Expression in the group of cells initiating
ovuliferous scale primordia is shown by arrowheads (magnification
×45). c and d, SCB at stage 2. Ovuliferous scale primordia shown by
arrowheads (magnification ×100 and ×11.25, respectively). e,
Cross-section of SCB at stage 3. Ovuliferous scale primordia shown by
arrowheads (magnification ×55). f and g, SCB at stage 3 (magnification
×45 and ×8.3, respectively). h, DSB with initiating needle primordia
(arrowheads) (magnification ×90). i, DSB with developing needle
primordia (arrowheads) (magnification ×45). j and k, Differentiated
PCB with initiating microsporophylls (stage 1). Two layers of tapetal
cells surrounding pollen mother cells are shown by arrowheads
(magnification ×45 and ×60, respectively). l, PCB after completion of
microsporophyll initiation (stage 2) (magnification ×23.5). All
sections except b and e, which are cross-sections, are longitudinal.
ap, Apical meristem; bp, bract primordia; mi, microsporophylls; pmc,
pollen mother cells; sc, sterile cataphylls; and spc, sporogenous
cells.