Fig. 1. Identification of RSW7 by recombinational mapping, candidate gene sequencing and complementation. (A) Representation of a part of arabidopsis chromosome 2 showing the positions of SSLP markers used in mapping. White boxes represent AGI-BAC clones. Numbers are recombination events for each marker in a total of 1920 examined chromosomes. (B) Enlargement of the region between SSLP-markers ciw34 and ciw41, showing the names of BAC clones, as well as the position and the number of recombinants. The candidate gene, At2g28620, is depicted as a white box. (C) Exon-intron structure of the kinesin-like gene At2g28620 and the single nucleotide polymorphism in rsw7 (G in wild-type to A in rsw7) found in the fourth exon. Base and amino acid numbers indicate position in the gene. (D) Identification of rsw7 plants by PCR. The polymorphism destroys a BslI restriction site (CCN₇GG) in rsw7, therefore representing a CAPS marker (primers shown as underlined sequences). Base numbers on right indicate position in amplified sequence. The gel shows a DNA standard (left), BslI digests of rsw7 (middle) and wild-type (right) PCR products. The predicted sizes of the digested fragments are shown. (E) Complementation of the rsw7 root phenotype with the wild-type At2g28620 gene. Shown is the segregation in the T2 progeny of an rsw7 mutant transformed with an 11.8 kb genomic fragment containing the AtKRP125c gene. Arrows indicate T2 plants with rsw7 phenotype.