Question

Which of the following lists has the steps involved in the whole genome shotgun approach to Sequencing in the correct order?

1) Isolation and shearing of genomic DNA, Insertion of genomic fragments into cloning vector, Transformation of E. coli with cloning vector, Sequencing of cloned fragment ends, Sequence assembly
2) Isolation and shearing of genomic DNA, Insertion of genomic fragments into cloning vector, Transformation of E. coli with cloning vector, Sequencing of cloned fragment ends, Sequence assembly
3) S1 nuclease digest of single-stranded tails, Isolation and shearing of genomic DNA, Insertion of genomic fragments into cloning vector, Sequencing of cloned fragment ends, Sequence assembly
4) Sequence assembly, Insertion of genomic fragments into cloning vector, Transformation of E. coli with cloning vector, Sequencing of cloned fragment ends, Isolation and shearing of genomic DNA

Answer 1

The steps of the whole genome shotgun approach, in the correct order, are isolation and shearing of genomic DNA, insertion of genomic fragments into cloning vector, transformation of E. coli with cloning vector, sequencing of cloned fragment ends, and sequence assembly. (option 1)

Step-by-step explanation:

The whole genome shotgun approach involves several steps to sequence an entire genome effectively. These steps are:

Isolation and shearing of genomic DNA, which means preparing genomic DNA of a specific length for cloning by isolating and then breaking it into smaller, overlapping fragments.

Insertion of genomic fragments into a cloning vector, also known as ligation, where these smaller fragments are inserted into vectors such as plasmids that can replicate within a host organism.

Transformation of E. coli with cloning vector, which entails introducing the recombinant DNA into E. coli cells where each transformed cell will carry a copy of a fragment from the original genome.

Sequencing of cloned fragment ends, where an automated sequencer is used to determine the sequence of the DNA at the ends of these cloned fragments.

Sequence assembly, is a computational process where the overlapping sequenced fragments are aligned and merged to form continuous sequences or contigs that represent the entire original genome.

Looking at the options provided by the student, option number 1 follows the correct order of steps for the whole genome shotgun approach to sequencing.