The image above shows a double Holliday junction formed duri

The image above shows a double Holliday junction formed during processing of a double strand DNA break. If the Holliday junctions were resolved using the cleavage sites specified by the arrow points, what allelic combination of genes A and B would be produced?

Solution

Answer:

AB and ab

Holliday junctions are a key intermediate in many types of genetic recombination, as well as in double-strand break repair. These junctions usually have a symmetrical sequence and are thus mobile, meaning that the four individual arms may slide through the junction in a specific pattern that largely preserves base pairing.