The T-DNA insertion in the fil-9 allele. (A) Genomic structure of FIL showing the T-DNA insertion in the fil-9 allele (triangle). Boxes correspond to exons and the black lines to introns. (B) Schematic representation of FIL protein structure. Boxes represent protein domains encoded by different exons. FIL functional domains: Zinc (ZN)-Finger domain (aa 30-57), self-interaction domain (aa 45-107) and DNA-binding domain (YABBY; HMG-related [26, 52]) (aa 120-180), according to ExPASy , are designated above the protein structure. The locations of the T-DNA insertion or the amino acid changes in different fil mutant alleles are indicated below the protein structure. (C) RT-PCR analysis of FIL mRNA levels in fil-9. Top panel, PCR analysis was performed using FIL primers P1 and P2 (location indicated in A) to detect the transcript encoded by the region upstream to the T-DNA insertion. Middle panel, PCR analysis was performed using FIL primers P3 and P4 (location indicated in A) to detect that part of the transcript encoded by the region downstream to the T-DNA insertion. Lower panel, the TUB4 mRNA level was used as a control. The numbers above the lanes indicate the number of PCR cycles performed.