Question

# The specificity of restriction enzyme recognition can be used to detect mutations. For example, the enzyme MstII cuts DNA at CCTNAGG, where N is any base. Around the sixth codon in the$\beta - g l o b i n$gene is the sequence CCTGAGG. There are two additional MstII sites on either side of the sixth codon, such that when MstII is used to cut human DNA in this region, two fragments of 1.15 and 0.20 kilobases are obtained (1 kilobase = 1,000 bp). The sickle allele of the$\beta \text { -globin }$gene causes sickle-cell anemia when it occurs in the homozygous state. In this allele, the sequence around the sixth codon is mutated to CCTGTGG. How can this information be used to make a DNA test for these alleles?

Solution

Verified
Step 1
1 of 2

Gel electrophoresis can distinguish between fragments of different sizes. As we know due to SPM in $\beta$ -globin gene $\textit{Mst}$II cuts DNA with sickle allele and healthy allele into fragments of different sizes. We can use fragments produced from sickle allele as a $\textit{standard for comparison}$ to identify the unknown allele's fragments 'sizes using gel electrophoresis. If the distance traveled by an unknown fragment is similar to that of in a standard well, it means that DNA belongs to the sickle allele.

## Recommended textbook solutions

#### Campbell Biology, AP Edition

9th EditionISBN: 9780131375048 (1 more)Cain, Jackson, Minorsky, Reece, Urry, Wasserman
715 solutions

#### Campbell Biology, AP Edition

10th EditionISBN: 9780133447002Cain, Campbell, Minorsky, Reece, Urry, Wasserman
1,705 solutions

#### Campbell Biology

11th EditionISBN: 9780134093413 (1 more)Jane B. Reece, Lisa A. Urry, Michael L. Cain, Peter V Minorsky, Steven A. Wasserman
1,679 solutions

#### Principles of Life

2nd EditionISBN: 9781464109478 (1 more)David E. Sadava, David M. Hillis, Mary V Price, Richard W Hill
880 solutions