Record Details
The size of the chromosome segment transduced by phage Pl.
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The size of the chromosome segment transduced by phage Pl. |
| Names |
Cowan, Judith Harmon Miller
(creator) Fraser, Dorothy K. (advisor) |
| Date Issued | 1966-10-07 (iso8601) |
| Note | Graduation date: 1967 |
| Abstract | The purpose of this research was to determine whether the transducing phage Pl picks up original bacterial chromosome segments and whether these segments are always the same size. The plan of approach was to grow the donor bacteria Escherichia coli C600 gal⁺ (galactose) in minimal media containing the heavy isotopes ¹⁵nitrogen and deuterium in place of light nitrogen and hydrogen. The heavy isotopes were incorporated into the chromosomes of the donors which were infected with light Pl and allowed to lyse in light media. As a result, only transducing particles contained the heavy DNA picked up from the chromosome. This lysate, plus nontransducing Pl and Streptococcus lactis phage c2 as references, was studied by density-gradient centrifugation in a cesium chloride solution. Drops were collected in individual tubes and assayed for active Pl, transducing Pl, and c2. The recipient for transduction was E. coli W3350 S[superscript r] gal⁻. On a graph plotted of titer versus drop number, three peaks were evident: active Pl, transducing Pl, and c2. The peak of the transducing particles was cone-shaped and denser than the peak of active Pl, indicating the following: (1) original heavy chromosome material was incorporated into all the transducing particles; (2) none of the chromosome fragments had replicated, since no half-heavy or light transducing particles were found; (3) all chromosome fragments were the same size or very nearly the same size. |
| Genre | Thesis/Dissertation |
| Topic | Bacteriophages |
| Identifier | http://hdl.handle.net/1957/47707 |
