Multiple Translocation of the AVR-Pita Effector Gene among Chromosomes of the Rice Blast Fungus Magnaporthe oryzae and Related Species
Figure 7
Molecular evidence suggesting the course of evolution of the AVR-Pita family.
(A) A Bayesian tree constructed from exon sequences of AVR-Pita homologs. The number on each branch indicates posterior probability. The tree was rooted using AVR-Pita3 [39] as an outgroup taxon. Shaded are representative homologs whose flanks were analyzed in detail (see Figure 6). Asterisks indicate homologs used for the transformation assay (see Figure 8). The function of the homologs as an avirulence gene, which were deduced from the transformation assay and sequence analyses, is represented by + (functional) and – (nonfunctional) in the “function as AVR-Pita” column. Chromosomes carrying the homologs are shown in the “chromosome” column. “S” represents a supernumerary chromosome. The RFLP types of the homologs and structures of their flanks are depicted in the right column. See Figure 6 for legends of symbols. Cl-X, Cl-Y, and Cl-Z indicate three major clusters found in the present study. (B) Structure at the 5′ flanks of AVR-Pita homologs suggesting a horizontal transfer. (C) Structures at the 3′ flanks of AVR-Pita homologs suggesting stepwise stacking of blocks of DNA fragments. Each block is painted in a distinct color. Corresponding blocks in the diagrams (upper panel) and the nucleotide sequences (lower panel) are shown in the same color. Red boxes indicate telomere repeats. Underlines indicate nucleotide substitutions.