CHROMOSOMAL LOCATION OF THYMINE AND ARGININE GENES IN ESCHERICHIA COLI AND AN F′ INCORPORATING THEM

Ishibashi, Masahide (Osaka University, Osaka, Japan),Yoshinobu Sugino, and Yukinori Hirota . Chromosomal location of thymine and arginine genes inEscherichia coli and an F′ incorporating them. J. Bacteriol.87: 554–561. 1964.—The gene responsible for thymine requirement or independence inEscherichia coli K-12 is located on the chromosome, nearArg 2 (arginine) and betweenSm (streptomycin) andAde (adenine). A new F′ (called F15 ) carrying theThy (thymine) gene as well as theArg 2 gene was discovered. TheThy + (thymine independent) gene on F15 relieves the defect of allThy − (thymine requiring) mutants ofE. coli examined, such asE. coli 15 T− , B3, andThy − mutants obtained by aminopterine treatment. It can also be transferred toThy − mutants ofSalmonella typhimurium andSerratia marcescens , converting them toThy + .