Are Gene Symbols case sensitive or insensitive?

Question

[fbrundu]

Hi,

maybe it's a stupid question, but, are gene symbols supposed to be case sensitive or case insensitive?

E.g. GENE1, gene1, GenE1 represent the same gene?

Thanks

[Neilfws]

Not a stupid question at all. "Naming things" (sensibly) is one of the great problems in computer science and is something that biologists have ignored for years :)

Answer 1

[Devon Ryan]

It'll depend on the organism. Human genes, for example, are always upper case (e.g., "GENE1"), with the exception of ORFs (e.g., C17orf12, which probably doesn't exist). Mouse genes, on the other hand, have a capitalized first letter and the rest lower case (e.g., "Gene1", which also needs to be italicized). In neither of those would a gene named "GenE1" exist. Having said that, you may see things like "GenE1" in print, since it's sometimes easier to see that that means gene family "Gen" subgroup "E" member "1", though it's often not technically correct. Technically a drosophila gene could be named "GenE1", since there's no strict rule on case (everything after the first letter is normally lower-case, but there's no "must" in that rule).

[fbrundu]

Thanks, very clear. But, to be more specific, if I have a gene called GENE1, is it possible to have a different gene called e.g. Gene1 (belonging to another organism and possibly having different functions)?

[Devon Ryan]

Yes, that's completely possible, though they'll often be homologs of one sort or another.

[Madelaine Gogol]

Happens all the time.

Also, sometimes, the lowercase of a gene name (at least in yeast) is used to mean a strain with that gene deleted. Hopefully with a delta in front of it.