Figure 3
Minimum spanning tree of rDNA (ITS1+5.8S+ITS2) haplotypes. Haplotypes are represented by colored circles (red for X-chromosome sequences, green for B-chromosome sequences and different shades of blue for M8, S9, S10 and S11 sequences). Blank circles represent haplotypes obtained from genomic DNA (0B or +B). Each black dot represents a mutational step. Four haplotype groups are clearly differentiated, corresponding to chromosomes S11, X, B24, and a final group that includes chromosomes for M8, S9 and S10, with the exception of a sequence from the B24 chromosome grouped with the sequences from the X chromosome. For each group, we represented the secondary structure of the most stable sequence for ITS1 (i.e. with the lowest Gibbs free energy). The secondary structure of ITS2 showed no notable differences between these groups, but we show the secondary structure of the most stable ITS2 sequence from the B24 chromosome to indicate (with an arrow) the position of an additional characteristic adenine present only in B24 sequences. We indicate the number of each helix with Roman numerals. A full color version of this figure is available at the Heredity journal online.
