ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Density-gradient centrifugation analysis of the DNA extracted from Escherichia coli cells infected with 32P- and bromouracil-labeled phage and incubated with KCN showed the formation of linear molecules composed of two components de rived from the parental DNA molecules joined end-to-end by hydrogen bonds (joint molecules). However, when the infected cells were incubated under conditions which permitted limited synthesis of phage DNA, the components which had been derived from the parental DNA were joined by covalent bonds to form recombinant molecules. It was also found that the structure of the majority of the chromosomes of mature phage T4, including heterozygous ones, could be represented by a duplex DNA molecule without an interruption in the strands. Studies on the genetic control of recombination of phage T4 showed that gene 32 has to be expressed to form joint molecules, and that some other genes essential for DNA synthesis are involved in the transformation of joint molecules to recombinant molecules. These results indicate that the process of genetic recombination is composed of several events: (a) formation of joint molecules, (b) their conversion to recombinant molecules, and (c) determination of chromosomal size followed by maturation. Joint molecules isolated from the cells can be converted to recombinant molecules by an extract prepared from infected or uninfected cells. In order for the reaction to proceed, deoxyribonucleotide triphosphates are essential.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1040700414
