Table 1.

Curation of alternative splicing literature has reveals 23 human genes and 20 mouse genes with functionally distinct splice isoforms (FDSIs)

Species	Curated genes	Genes with FDSIs	Studies curated	Study Type
				Isoform Removal	Overexpression	Localization	Other study types
Human	555	23	903	149	294	80	380
Mouse	227	20	272	82	70	37	83
Total	782	43	1127	222	353	109	443

The 23 human genes with FDSIs accounted for almost 4% of human genes annotated in this knowledgebase, while the 20 mouse genes accounted for 9% of the all mouse genes annotated. The majority of curated studies could be classified into three different types: “isoform removal”, “overexpression” and “localization”. Isoform removal studies have experiments where expression of at least one splice isoform is eliminated and a phenotypic change is evaluated. Overexpression studies have experiments where at least one splice isoform is overexpressed. This “abundance” of the splice isoform can cause a phenotype (not necessarily distinct). Localization studies have experiments that characterize where in the cell or organism the splice isoform is expressed. A single study can report experiments with multiple study types. The total number of human and mouse studies curated do not sum to 1158 studies because some publications investigated both human and mouse forms of a single gene