Question

In an analysis of the p53 gene for mutations, the following sequences were produced. For each sequence, write the expected sequence of the opposite strand that would confirm the presence of the mutations detected.

A. Normal: 5'TATCTGTTCACTTGTGCCCT3'
B. Homozygous substitution: 5'TATCTGTTCATTTGTGCCCT3'
C. Heterozygous substitution: 5'TATCTGT(T/G)CACTTGTGCCCT3'
D. Heterozygous deletion: 5'TATCTGTT(C/A)(A/C)(C/T)T(T/G)(G/T)(T/G)(G/C)CC(C/T)(T/...3'

Answer 1

The expected sequences for each mutation are: A. Normal: 5'ATGGAACAGTGAAACACGGGA3', B. Homozygous substitution: 5'ATGGAACAGTAAACACGGGA3', C. Heterozygous substitution: 5'ATGGAACAGTAACTTGTGCCCT3', D. Heterozygous deletion: 5'ATGGAACAGTCCTCCAGCTGTTGCAGACCC3'.

Step-by-step explanation:

In an analysis of the p53 gene for mutations, the sequences provided represent the template strand of DNA. To determine the complementary DNA sequence, we would need to identify the Watson-Crick base pairing rules: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). Here are the expected sequences for each mutation:

A. Normal: 5'ATGGAACAGTGAAACACGGGA3' (complementary to 5'TATCTGTTCACTTGTGCCCT3')

B. Homozygous substitution: 5'ATGGAACAGTAAACACGGGA3' (complementary to 5'TATCTGTTCATTTGTGCCCT3')

C. Heterozygous substitution: 5'ATGGAACAGTAACTTGTGCCCT3' (complementary to 5'TATCTGT(T/G)CACTTGTGCCCT3')

D. Heterozygous deletion: 5'ATGGAACAGTCCTCCAGCTGTTGCAGACCC3' (complementary to 5'TATCTGTT(C/A)(A/C)(C/T)T(T/G)(G/T)(T/G)(G/C)CC(C/T)(T/G)(A/C)(C/A)(G/G)(A/T)(C/G)(G/C)(C/T)(T/T)(C/G)3')