Figure 1.
Different 5S ribosomal DNA and U1 small nuclear DNA tandem arrangements sampled from razor shell species. For each species, drawings were constructed using sequences retrieved from the same individual. Drawings are done to scale (except dash lined boxes). (a) Grey IGSs are very similar (identities=90%, gaps=2%, E value=1 × 10−93); yellow NTSs are similar but the darker one has a deletion of 160 nts (identities=90% in both aligned regions, gaps=4% in the first region and gaps=1% in the second region, E value=4 × 10−58) . Blue and yellow NTSs are very divergent and could not be aligned. Blue, o-NTS; light yellow, π-NTS; dark yellow, ρ-NTS. (b) NTSs are very divergent and could not be aligned. Grey, ν-NTS; brown, ξ-NTS. (c) Both IGS (same colour) are identical. The three NTS are very divergent and could not be aligned. Red, λ-NTS; light blue, μ-NTS; orange, κ-NTS. (d) Green NTSs (both η) are very similar (identities=82%, gaps=9%, E value=0), red IGSs are also very similar (identities=92%, no gaps, E value=1 × 10−93). Yellow NTS corresponds to ζ-group. 5S, 5S ribosomal RNA coding region; U1, U1 small nuclear RNA coding region; NTS, nontranscribed spacer; IGS, intergenic spacer. (+) Reconstructed by overlapping clones from the same individual (see main text).