Isolation and complementation of mutants of Anabaena sp. strain PCC 7120 unable to grow aerobically on dinitrogen
Mutants of Anabaena sp. strain PCC 7120 unable to grow aerobically on dinitrogen were isolated by mutagenesis with UV irradiation, followed by a period of incubation in yellow light and then by penicillin enrichment. A cosmid vector, pRL25C, containing replicons functional in Escherichia coli and in Anabaena species was constructed. DNA from wild-type Anabaena sp. strain PCC 7120 was partially digested with Sau3AI, and size-fractionated fragments about 40 kilobases (kb) in length were ligated into the phosphatase-treated unique BamHI site of pRL25C. A library of 1054 cosmid clones was generated in E. coli DH1 bearing helper plasmid pDS4101. A derivative of conjugative plasmid RP-4 was transferred to this library by conjugation, and the library was replicated to lawns of mutant Anabaena strains with defects in the polysaccharide layer of the envelopes of the heterocysts. Mutant EF116 was complemented by five cosmids, three of which were subjected to detailed restriction mapping; a 2.8-kb fragment of DNA derived from one of the cosmids was found to complement EF116. Mutant EF113 was complemented by a single cosmid, which was also restriction mapped, and was shown to be complemented by a 4.8-kb fragment of DNA derived from this cosmid.
- Research Organization:
- Michigan State Univ., East Lansing (USA)
- OSTI ID:
- 6758586
- Journal Information:
- J. Bacteriol.; (United States), Vol. 170:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CYANOBACTERIA
GENE REGULATION
NITROGEN FIXATION
AEROBIC CONDITIONS
COSMIDS
DNA-CLONING
ESCHERICHIA COLI
GENETIC ENGINEERING
GENETIC MAPPING
MUTAGENESIS
MUTANTS
NITROGEN
ULTRAVIOLET RADIATION
BACTERIA
CLONING
DNA HYBRIDIZATION
ELECTROMAGNETIC RADIATION
ELEMENTS
HYBRIDIZATION
MAPPING
MICROORGANISMS
NONMETALS
RADIATIONS
550200* - Biochemistry
560130 - Radiation Effects on Microorganisms