an episome , f32 , which carries the genetic markers dsda ( + ) , the presumed structural gene for d-serine deaminase , dsdc ( + ) , a regulatory locus governing the synthesis of d-serine deaminase , aroc ( + ) , and purc ( + ) was obtained from strain ab311 of escherichia coli k-12 , and was used to construct appropriate merodiploids with dsdc markers .
C0017393
genetic markers
C0005516
markers