Highlight specific genomic coordinates

[SarahLampert]

New feature

I’d like to propose adding an option to highlight specific genomic coordinates in the Sashimi plot output.
This feature would allow to emphasize a particular region of interest while still displaying the full splicing landscape of the selected region.

Usage scenario

This feature would be particularly useful when analyzing alternative splicing events that may be driving a phenotype.
Instead of manually searching for specific junctions in different samples, users could specify coordinates or junctions of interest, which would then be highlighted. This would make it easier to compare specific regions between multiple samples and assess whether suspected splicing events are consistent across conditions or phenotypes.

Suggest implementation

The main building blocks of a possible implementation:

1. New argument for specifying genomic coordinates to highlight. (Could accept a list of multiple regions)

2. Potential visualization options:

   • Highlighted region on the plot
   • Distinct color for the splice junction arcs corresponding to the coordinates

3. If multiple samples are plotted, the same region should be highlighted consistently across all plots to facilitate direct comparison.