Escherichia coli Chromosome (image) Indiana University Caption This circle represents the Escherichia coli chromosome with 1,931 mutations. Blue lines represent base-pair substitutions and green lines represent the gain or loss of between one and four nucleotides. Credit Andrew J. Hanson, School of Informatics and Computing, Indiana University Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.