By reading some articles using RNAseq data, I've seen many times the word "Isoform Ratios". Yet, in these articles it seems that it was trivial for them so they dont really explain what it is. But since I'm new to the field, I would like to know a bit more about it.
I try to google a bit about it but I couldn't find any clear mathematical definition for this. So, what exactly is an Isoform Ratio and is there a mathematical definition/formula for it ?
It would be idea if you could reference the articles as an example. By intuition, it could refer to the ratio of an isoform over all the existing isoforms of a specific gene. This could indicate the abundance of one isoform vs the others.
Genes give rise to transcripts. Transcripts which differ in structure due to splicing, editing, or transcriptional events are called isoforms. A given gene may produce multiple isoforms. Since transcripts are measured by RNA Seq, it is useful to think in terms of isoform ratios (if you can indeed effectively distinguish them in your measurements). Aside from regulating the total transcriptional output of a gene, a gene may be undergoing regulation to switch between various isoforms, thus altering isoform ratios.
(unless, of course, you're talking about experiments involving incorporating different chemical isoforms in transcripts. As fracarb8 mentioned, it would be helpful to include a specific reference).
It would be idea if you could reference the articles as an example. By intuition, it could refer to the ratio of an isoform over all the existing isoforms of a specific gene. This could indicate the abundance of one isoform vs the others.