Empirical validation via in situ hybridization. (A-C) At1g33430 (anti-sense probe), (D-E) (sense control probe) noted signal on stamen and carpel primordial with strong expression detected in the tapetum and microspore as predicted by MPSS. (F-G) At2g19070 (anti-sense probe), (H) (sense control probe) signal identified on the tapetum. Stamen and petal localized expression predicted by MPSS (I-J) At1g54860 (anti-sense probe) signal on stigmatic papillae as well as septum and developing microspore. Predicted to be stamen-enriched by MPSS analysis. (K-L) At5g59810 (anti-sense probe) transient signal noted on a specific microspore of the tetrad. Carpel-enrichment predicted by MPSS. (M) At1g72290 (anti-sense probe) signal identified on the septum. Predicted to be localized within the stamen and the carpel by MPSS. (N) At2g42940 (anti-sense probe) (O) (sense control probe) weak signal on stamen and carpel primordial. Identified as a putative stamen-enriched transcript by MPSS. (P) AP3 (anti-sense control probe).