Question

Classical DNA sequencing is a powerful technique. Consider a situation where you first sequence a normal strand of DNA, then sequence a mutated strand. When analysing the results of sequencing reactions, run on a gel, would you be able to distinguish each of the following mutation types, compared to unmutated sequence, using classic "Sanger" sequencing?

Question 2

Answer 1

1.- Remember that Sanger sequencing will throw the complete nucleotide sequence so you will be able to distinguish each nucleotide base in each position.

a) Silent mutation: This is a mutation that changes the codon but the new codon codes for the same amino acid. Sure you will be able to note this with Sanger sequencing, it will appear as a substitution in the respective site

b) An insertion of 6 nucleotides: Sure you will be able to notice this with Sanger sequence, in the alignment you will notice it by the presence of a gap in the unmutated strand

c) A sense mutation: This is actually the same to silent mutation, you will see this as a substitution in the respective site

2.- The phoshphodiester bond is the one that links each nucleotide in the back bone of DNA, a break in this bonds means a complemete break in the DNA strand. The factors capable of doing this are Topoisomerase, Deadenylase and Spliceosome.