Question

12. During homologous recombination, what events are required for formation of the heteroduplex?

13. Assume that homologous recombination occurs across a region of DNA containing a wild-type and mutant allele of a particular gene. There is a single base pair change in the mutant allele as follows:

wild-type = 5’…TTGGGTA… à5’…TTGCGTA… = mutant allele, such that the resulting dsDNA is as follows:

     5’…TTGGGTA…

     3’…AACGCAT…

What would be the genotype (wild-type or mutant) if base excision repair occurs on the TOP strand?

14. What term describes the process occurring above?

Answer 1

12) for the formation of heteroduplexes the following event need to occur.

- Presence of the wild type and mutant allele or DNA

- Denaturation of the DNA strands of both forms

- slow renaturation or annealing of the fragments. This way heteroduplexes can be formed.

13) the genotype will be mutant. As the non template strand is the top one, the ptotein that will be produced will be from the mutant allele.

14) the process above is known as base excision repair