Question

Homologous recombination occurs in a heterozygote in which alleles D and d differ by a single base pair. The D allele has a G (a GC base pair) at one position, whereas the d allele has a C (a CG base pair) at the same position. If branch migration causes heteroduplex formation across this position, what is the expected outcome

Answer 1

Answer:

Mismatch DNA repair mechanism recognizes the abnormal base pairing (G-G base pair) and may correct it by converting the D allele to d

Explanation:

The DNA mismatch repair can be defined as a specialized mechanism that recognizes and repairs errors in the nuclotide sequence (such as, for example, bases erroneously incorporated) during DNA replication and recombination. The DNA mismatch repair is a system that also acts to repair the DNA after damage. It has been shown that the DNA mismatch repair mechanism leads to the generation of a DNA molecule with one chain that has the nucleotide sequence arising from DNA repair and one parental chain. In this case, it is expected that the DNA mismatch repair mechanism will identify the abnormal G-G base pairing and then this system may change the D allele to a d allele by introducing a C base instead of a G base in the DNA strand.