Figure 2.

miR399 targets the 5′-UTR of maize GRMZM2G381709, a PHO2 homolog. A, GRMZM2G381709 gene structure: exons are red blocks, introns are black lines, 5′-UTR and 3′-UTR are brown blocks. Inset shows the 5′-UTR region with predicted miR399 target sites numbered 1-6 and shown in black. Barplot shows the frequencies of 5′-ends recovered from sequenced 5′-RACE products. Four 5′-RACE cleavage products, each sequenced once, are not shown here; they were found approximately 4 kb upstream of the ATG, spanning a region of 343 bp. B, Alignments of miR399 and GRMZM2G381709 at sites 5 and 3. Arrows indicate the terminal positions of the sequenced 5′ RACE cleavage products and the fraction of clones corresponding to these positions.