Adenine auxotrophic heterozygosity inCandida krusei

Sex-linked auxotrophic and putative auxotrophic mutants of Drosophila melanogaster.

Thirty-two mutants with improved growth response on a yeast-sucrose compared with a defined medium have been characterized with respect to ribonucleoside supplementability. Twenty mutants respond to either pyrimidine ribonucleoside. Four mutants respond to one or both purine ribonucleosides. Eight mutants ("putative" auxotrophs) do not respond to dietary RNA supplementation. Mapping and complem...

Isolation and characterization of mutants of Saccharomyces cerevisiae auxotrophic and conditionally auxotrophic for 5'-dTMP.

An improved method for isolation of yeast m utants auxotrophic for 5'-dTM P is presented. The procedure employs the two folic acid antagonists aminopterin and sulfanilamide (SA A). Selec­ tiveness of the procedure depends on concentration of SAA and time of incubation. 44 mutants auxotrophic and 3 conditionally auxotrophic for 5'-dTMP were isolated. All belong to one complementation group. The ...

Generation of auxotrophic mutants of Enterococcus faecalis.

A 22-kb segment of chromosomal DNA from Enterococcus faecalis OG1RF containing the pyrimidine biosynthesis genes pyrC and pyrD was previously detected as complementing Escherichia coli pyrC and pyrD mutations. In the present study, it was found that the E. faecalis pyrimidine biosynthetic genes in this clone (designated pKV48) are part of a larger cluster resembling that seen in Bacillus spp. T...

Rescuing auxotrophic microorganisms with nonenzymatic chemistry.

Auxotrophic mutation and infectivity of Agrobacterium tumefaciens.

Pathogenicity of many microorganisms depends on their ability to metabolize and often to multiply in the host (Garber, Ann. N.Y. Acad. Sci. 88:1187, 1960; Panos and Ajl, Ann. Rev. Microbiol. 17:297, 1963). Both of these processes may be altered by mutation of the bacterium to auxotrophy, particularly if the host fails to provide an adequate source of the required metabolite in the infection cou...