1.3 Making sense of the sequences

The chart flows downwards through three distinct steps, each with illustrative graphics on the left and descriptive labels on the right.

Step 1: DNA fragment sequencing: a scattered group of approximately twelve small, curved grey and coloured lines representing fragmented DNA pieces.

An arrow then points downwards to the next step.

Step 2: Overlapping windows matching: three horizontal text strands of DNA base letters arranged to show overlap.

• First strand (red text): CGAGATTAGCTGCA
• Second strand (blue text): placed slightly lower and shifted right, reading TGCATAGCGATATCA
• Third strand (green text): placed below the red text / first strand but above the blue text / second strand still and shifted right, reading TATCATGATTA.

A black bounding box frames the overlapping TATCA letters between the blue and green strands, and another black bounding box frames the overlapping TGCA letters between the red and blue strands.

An arrow then points downwards to the next step.

Step 3: Local DNA Reassembly: a single, continuous line of dark blue text underlined by a solid blue bar. It shows the completely merged sequence: CGAGATTAGCTGCATAGCGATATCATGATTA.

Diagram explaining Metagenomics workflow. From top left, going clockwise:

Sample to DNA fragmentation: a bold arrow points from the word ‘Sample’ to a cluster of horizontal, multi-coloured lines (red, green, blue, yellow, black) representing fragmented strands of DNA.

Shotgun sequencing: an arrow points right toward an illustration of a laboratory genomic sequencing machine. A small box above the machine displays rows of raw genetic text characters (A, C, T, G).

Sequence(s) assembly: an arrow points down to perfectly aligned, sorted horizontal colour bars, representing the short reads being reconstructed into continuous sequences.

Identification (taxonomic assignment): an arrow points left toward a laptop computer displaying a globe icon. Surrounding the laptop are small illustrations of diverse biological organisms, including a green fish, a yellow worm, a black bacterium, and a red virus, signifying species identification.