Gene Maps: Locus Order, Orientation, and Distance

Distinguish locus order, physical coordinates and genetic distance. Learn what a gene map needs to state about its reference and scale.

Open the Gene Map Maker to draft the visual, then use the topic-specific checks below to review it.

Original AI-generated gene map teaching reference. Positions are schematic and not to scale.

Choose the map type first

A physical map uses sequence positions; a genetic map uses recombination-based distances. A gene map maker can visualize either supplied description, but the units and source must remain explicit. Do not combine the two scales on one unlabeled axis.

Supply a reference with every coordinate

The same locus may have different positions across assemblies or transcripts. Record the reference sequence, assembly and coordinate convention before drawing. If you only know order, use a schematic layout rather than inventing a scale.

Review orientation and feature intervals

A gene can span an interval, while a marker may be a single position. Distinguish boxes from ticks and use arrows only when direction is meaningful. Compare every label with the supplied feature list after generation.

Reference key

Mistakes to check

Treating cM as a fixed number of base pairs

Recombination varies across genomic regions and contexts. Keep physical and genetic units separate.

Inventing missing coordinates

Unknown positions should remain unknown. A visually balanced layout must not imply measured spacing.

Omitting the assembly

Coordinates without a reference are ambiguous. Add the assembly or accession and state whether positions are one-based or zero-based where relevant.

From feature list to a readable caption

Write the reference before the positions: assembly or accession, region, coordinate convention and units. If gene intervals overlap, explain the row layout instead of moving them to make the picture neat. Keep the original feature list beside the image for review; a generated picture is not a new coordinate record.

Common questions

Does the gene map maker calculate linkage?

No. It visualizes positions and order supplied by the user; it does not infer linkage or calculate recombination frequencies.

Can I supply base-pair coordinates?

Yes. Include the reference assembly, coordinate convention and feature intervals, then verify the final image against that list.

Can I draw only the locus order?

Yes. Label the output as schematic or not to scale so spacing is not misread as distance.

Is this a plasmid map tool?

This page focuses on linear loci and genomic regions. Use the Plasmid Map Maker for circular construct features.

Sources and editorial notes

• NHGRI: Genetic map
• NHGRI: Physical map

Prepared by the AcaDraw product team on November 14, 2026. The reference illustration is original AI-generated artwork. It is a simplified explanatory model, not an experimental result, production specification or independently reviewed analysis.