CGSC Strain#: 6510
Strain Designation: F26      Source of Strain: B. Sedgwick
Sex: F- Chromosomal Markers: lon-11, sulA1, his-222, thyA751
Strain Comments:

• lon-11-- is a mutation of an E. coli B gene caused by an IS186 insertion in the promoter. All derivatives of Witkin's B wildtype carry this lon mutation.
• his-222-- Not a K-12 mutation. (mutation of an E. coli B gene)
• thyA751-- Mutation in E. coli B gene
• thyA751-- Strains with this marker must have their medium supplemented with thymine (25ug/ml). This is true even for rich medium such as LB. Otherwise thymine starvation can lead to thymineless death.

References:

• Sedgwick, B., P. Robins 1980. Isolation of mutants of Escherichia coli with increased resistance to alkylating agents: mutants deficient in thiols and mutants constitutive for the adaptive response. Mol.Gen.Genet. 180:85-90
• Sedgwick, B. 1982. Genetic mapping of the ada and adc mutations affecting the adaptive response of Escherichia coli to alkylating agents. J.Bacteriol. 150:984-988