You set up an EcoRI restriction digest for a sample of genomic DNA from an individual with a mutation in the β-globin gene. You perform a Southern blot using the entire β-globin gene as a probe. To your surprise, you notice a different pattern of bands in the affected individual - you have identified a new SNP! What can you conclude from the pattern of bands from the Southern blot below?

Question

Quizplus · Accepted Answer

The different pattern of bands suggests that the mutation created a new EcoRI site, resulting in smaller fragments compared to the wild-type DNA. This is supported by the presence of an additional band in the affected individual lane, indicating that the EcoRI enzyme cut at the new site, producing a smaller fragment. A loss of an EcoRI site would result in larger fragments compared to the wild-type DNA. A loss of an exon or creation of a new HindIII site would not necessarily affect the EcoRI restriction digest pattern. The presence of a new SNP within the β-globin gene suggests that there is a change in the genomic DNA sequence.

You Set Up an EcoRI Restriction Digest for a Sample