Figure 4.

RNA in Situ Hybridization Showing the Expression Patterns of CIKs in Early Wild-Type Anthers.

(A) to (E) CIK1 is expressed in the whole anther at stage 2 (St2) (A) and St3 (B), with higher level in L2-derived cells. The expression is concentrated in four locules with higher expression in the sporogenous cells and two layers of secondary parietal cells at St4 (C), MMCs, the tapetum and the middle layer at St5 (D), and MMCs and the tapetum at St6 (E).

(G) to (K) CIK2 shows expression patterns similar to CIK1 except that the signal is more obvious in the primary sporogenous cells at St3 (H).

(M) to (Q) CIK3 shows expression patterns similar to CIK1.

(S) to (W) CIK4 shows expression patterns similar to CIK1.

Sense probes of CIK1 (F), CIK2 (L), CIK3 (R), and CIK4 (X) were used as negative controls. One locule is shown for anthers at St4, St5, and St6. These experiments were repeated at least three times independently with similar results. ISP, inner secondary parietal cell; OSP, outer secondary parietal cell; PP, primary parietal cell; PS, primary sporogenous cell; Sp, sporogenous cell; T, tapetum. Bars = 20 µm.