Figure 1.

(A) Gene maps of ASAP3/TM6 and ASAP1 loci. Exons are shown as numbered boxes. The gene maps depicted are for the A copies of the loci. Upright and inverted triangles represent major deletions and insertions, respectively, that characterize the B duplicate copies. Numbers above the triangles provide the sizes of the indels. Arrows show positions of PCR primers used to isolate genomic sequences. Circles indicate approximate location of copy-specific RT-PCR primers used in gene expression assays. A 100-bp scale bar is provided. Relative sizes of exons and introns in the amplified regions were derived from comparison of genomic and cDNA sequences. Exon sizes outside the amplified regions are estimates based on comparison with data from A. thaliana orthologues. (B) Expression of the ASAP3/TM6 and ASAP1 floral regulatory genes in developing inflorescences of D. arborea. Expression was assayed with gene-specific primers (for the duplicate A and B copies) that amplified ≈300 nucleotides of cDNA in RT-PCR reactions. Control reactions using cloned A and B gene copies indicate the primers are copy-specific. Identity of amplified products was confirmed by sequencing.