Outline of a Genome Navigation System Based on the Properties of GA-Sequences and Their Flanks
Figure 2
Predominance of tetra-GA motifs in the pure GA-sequences of human chr. 1 as demonstrated by the GPxI method.
The highlighted field in the left hand panels are enlarged in the right hand panels.(Scales: 50[b]/division). a. The GPxI of a computer-constructed DNA file consisting of random sequences of G (white pixels) and A (black pixels). Therefore, no pixels with other gray-values are visible. The randomness is of the sequences is expressed by the lack of any detectable patterns. b. GPxI of the end-to-end concatenated pure GA-sequences of human chr. 1 shows clearly a number of patterns. Although different, they seem to share a periodicity of 4. c., d. Use of a modified Markham rotation [3] to demonstrate the prevalence of the 4-periodicity. In panel c the GPxI of panel b is superimposed on itself although frame shifted by 2 bases. The result is a rather featureless gray image. In panel d the applied frame shift is 4. The result is the almost identical re-appearance of the original GPxI, indicating that a frame-shift of 4 reinforces the prevalent patterns.