FCGR

Chaos Game Representation of Frequencies

Graphical representation of genomes and oligonucleotide frequencies. Each base (A, C, G, T) is mapped to a corner of a square and points are plotted iteratively, revealing the fractal patterns that are characteristic of the analysed sequence.

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Parameters

Paste the sequence to represent and set the image size.

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Description

Chaos Game Representation of Frequencies (FCGR)

The chaos game maps each nucleotide to a corner of a square: A (adenine) top left, C (cytosine) bottom left, G (guanine) top right and T (thymine) bottom right. Starting from the centre, every base of the sequence moves the current point halfway towards the matching corner, and that new position is plotted. After many iterations, fractal patterns emerge that are characteristic of the sequence.

The FCGR variant, as described by Deschavanne at al. (1999), represents frequencies of oligonucleotides rather than successive positions.

start A (Adenine) C (Cytosine) G (Guanine) T (Thymine)

This script has been extracted from online tools at insilico.ehu.es. CGR images for all sequenced bacterial genomes are available here. To understand how CGR images are generated, check here. Example representations for E. coli K12 : CGR, FCGR. Text taken from biophp.org.