Ectopic integration of chromosomal genes in Streptococcus pneumoniae

Journal Article · Fri Nov 30 23:00:00 EST 1984 · J. Bacteriol.; (United States)

OSTI ID:6057412

Mannarelli, B M; Lacks, S A

When a DNA fragment containing a marker gene was ligated to random chromosomal fragments of Streptococcus pneumoniae and used to transform a recipient strain lacking that gene, the gene was integrated at various locations in the chromosome. Such ectopic integration was demonstrated for the malM gene, and its molecular basis was analyzed with defined donor molecules consisting of ligated fragments containing the malM and sul genes of S. pneumoniae. In a recipient strain deleted in the mal region of its chromosome, these constructs gave Mal/sup +/ transformants in which the malM and sul genes were now linked, with malM located between duplicate sul segments. Ectopic integration was unstable under nonselective conditions; mal(sul) ectopic insertions were lost at a rate of 0.05% per generation. Several possible mechanisms of ectopic integration were examined. The donor molecule is most likely to be a circular form of ligated homologous and nonhomologous fragments that, after entry into the cell, undergoes circular synapsis with the recipient chromosome at the site of homology, followed by repair and additive integration.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 6057412
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 160:3; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

550400* -- Genetics
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BIOLOGY
CHROMOSOMAL ABERRATIONS
CHROMOSOME BREAKAGE
CHROMOSOMES
DNA
GENE RECOMBINATION
GENES
GENETICS
MICROORGANISMS
MUTATIONS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
RECOVERY
REPAIR
STREPTOCOCCUS