Strain A: Strain B: Leur Thr His- Trp- Mixture Glucose-salts agar Glucose-salts agar Control: No His* Trp+ mutants present Control: No Leu* Thr* mutants present -Glucose-salts agar Only prototrophic recombinants (Hist, Trp*, Leu*, Thr*) grow FIGURE 8.17 Experimental Demonstration of Horizontal Gene Transfer in Bacterla Recombinant colonies have genetic traits from both strains present in the mixture. Control plates demonstrate that these colonies are not a result of spontaneous mutation.
Genetic Recombination
Recombination is crucial to this process because it allows genes to be reassorted into diverse combinations. Genetic recombination is the process of combining genetic components from two different origins into a single unit. In prokaryotes, genetic recombination takes place by the unilateral transfer of deoxyribonucleic acid. It includes transduction, transformation, and conjugation. The genetic exchange occurring between homologous deoxyribonucleic acid sequences (DNA) from two different sources is termed general recombination. For this to happen, an identical sequence of the two recombining molecules is required. The process of genetic exchange which occurs in eukaryotes during sexual reproduction such as meiosis is an example of this type of genetic recombination.
Microbial Genetics
Genes are the functional units of heredity. They transfer characteristic information from parents to the offspring.
When demonstrating horizontal gene transfer, why is it important to use strains that each require at least two different amino acids?
Step by step
Solved in 2 steps