Genetic linkage of chromosomal tetracycline resistance and pigmentation to a purine auxotrophic marker and the isoleucine-valine-leucine structural genes in Staphylococcus aureus.

Three tetracycline resistance determinants (tmn-3106, tmn-3110, and tmn-3511) reported by Asheshov (1975) to be chromosomal in Staphylococcus aureus have been linked by transformation to a purine auxotrophic marker (pur-110), a cluster of eight genes involved in the biosynthesis of isoleucine, valine, and leucine (the ilv-leu region), a marker (ilvR10) that may be involved in the regulation of the ilv-leu region, and a gene involved in pigmentation (pig-131). The linkage group thus defined is tmn-3106-pur-110-ilvR10-(ilv-leu)-pig-131. The orientation of the ilv-leu region relative to ilvR10 and pig-131 was not determined. The tmn-3106, tmn-3110, and tmn-3511 determinants exhibit the same linkage relationships to the other markers. It is concluded that this linkage group represents a portion of the chromosome of S. aureus.