Below are four overlapping reads from sequencing.(Note: All reads are in a 5′-to-3′ direction.)
Read 1: AGCGCTAAAGACGGCTCGAGTCAGCTAGTAGAA
Read 2: TGCGTAGCTATCGCATACGCAAGCGCTAAA
Read 3: GCTAGTAGAATCGATATCGAGGATCGATTAG
Read 4: GGATCGATTAGAGCTATAGTAGGCTGATGAC
Which is the most likely order of these reads?
A) 1, 2, 3, 4
B) 1, 2, 4, 3
C) 2, 1, 3, 4
D) 2, 1, 4, 3
E) 3, 4, 2, 1

Question

Below are four overlapping reads from sequencing.(Note: All reads are in a 5′-to-3′ direction.) 
Read 1: AGCGCTAAAGACGGCTCGAGTCAGCTAGTAGAA
Read 2: TGCGTAGCTATCGCATACGCAAGCGCTAAA
Read 3: GCTAGTAGAATCGATATCGAGGATCGATTAG
Read 4: GGATCGATTAGAGCTATAGTAGGCTGATGAC
Which is the most likely order of these reads?
A) 1, 2, 3, 4
B) 1, 2, 4, 3
C) 2, 1, 3, 4
D) 2, 1, 4, 3
E) 3, 4, 2, 1

Quizplus · Accepted Answer

The most likely order of these reads is 2, 1, 3, 4. This is determined by finding the overlaps between the end of one read and the beginning of another. Read 2 ends with "GCTAAA" which overlaps with the beginning of Read 1 "AGCGCTAA...". The end of Read 1 "AGTAGAA" overlaps with the beginning of Read 3 "GCTAGTAGA...". Finally, the end of Read 3 "GATTAG" overlaps with the beginning of Read 4 "GGATCGATTAG...". This sequence of overlaps suggests the correct order is 2, 1, 3, 4.

Below Are Four Overlapping Reads from Sequencing