Fig. 1. afd1 encodes a REC8 homolog. (A) Partial sequence of AFD1 in the wild-type and afd1-1 mutant. In afd1-1, a G to A point mutation in the donor site of intron 16 (^) introduces a stop codon (^*). (B) Position of the Mu insertions in afd1-2, afd1-3 and afd1-4. (C) RT-PCR analysis of the afd1 gene compared with smc3 of root tips, leaves from 7-day-old and 21-day-old plants, ear at meiosis stage, tassel at meiosis stage, old-tassel-containing pollen. (D) RT-PCR analysis of the afd1 gene compared with smc3 in the tassel from wild-type and afd1 alleles for 30 and 35 PCR cycles. (E) Quantification of the RT-PCR signal shown in D as a percentage of the wild-type signal intensity. (F) AFD1 immunolocalization (green in merged) in wild-type and afd1 meiocytes stained with DAPI (red). Individual channels are shown in black and white for clarity. In the wild type, we observed a strong AFD1 signal between paired homologous chromosomes. In afd1 mutants, we enhanced the signal to detect any signal on the chromosomes, thereby increasing the background signal. No staining was detected on the afd1-1 and afd1-2 chromosomes. In afd1-3, patchy signals were detected in the nucleus (arrowheads). In afd1-4, the AFD1 signal was diffuse and lines could be detected suggesting preferential colocalization with chromosomes. Bars, 5 µm.