Bacterial Mutation and Conjugation 



315 



REFERENCES 



Lederberg, J., "Gene Recombination and Linked Segregation in Escherichia Coli," 

 Genetics, 32:505-525, 1947. Reprinted in Papers on Bacterial Genetics, Adelberg, 

 E. A. (Ed.). Boston: Little, Brown, 1960, pp. 247-267. 



Lederberg, J., "Bacterial Reproduction," Harvey Lect., 53:69-82, 1959. 



Lederberg, L. and Lederberg, E. M., "Replica Plating and Indirect Selection of Bac- 

 terial Mutants," J. Bact., 63:399-406, 1952. Reprinted in Papers on Bacterial 

 Genetics, Adelberg, E. A. (Ed.), Boston: Little, Brown, 1960, pp. 24-31. 



Lederberg, J., and Tatum, E. L., "Gene Recombination in Escherichia Coli," Nature. 

 London, 158-558, 1946. Reprinted in Classic Papers in Genetics, Peters, J. A. 

 (Ed.), Englewood Cliffs, N.J.: Prentice-Hall, 1959, pp. 192-194. 



QUESTIONS FOR DISCUSSION 



23.1. In previous chapters, has any evidence been presented that spontaneous muta- 

 tions are preadaptive? If so, state where. 



23.2. Suppose one thousand streptomycin-free test tubes are each inoculated with 

 one bacterium from a streptomycin-sensitive clone, and growth is permitted 

 until about one billion bacteria are present in each tube. When the contents of 

 each tube are plated on streptomycin-containing agar, what kind of result 

 would you expect if the mutations to streptomycin-resistance were postadaptive 

 in origin? Preadaptive in origin? From the expected results can you distinguish 

 between these two alternatives? How? 



Joshua Lederberg and Esther Marilyn Lederberg about 1951 . {Courtesy 

 of The Long Island Biological Association.) 



