help!!isoform!

[jialovelyjia]

Hello everyone!
I want to know the definition of the "isoform".I have known that the isoform is the result of alternative splice.But now,I want to know the professional and detail definition.I have searched this on the internet,but I failed.So,can you help me.Thank you!

[Bruins]

"isoforms n.plu. (1) the different forms of a polymorphic protein; (2) two or more proteins or RNAs that are produced from the same gene by differential transcription and/or differential RNA splicing."

E. Lawrence, Henderson's dictionary of biological terms, Pearson Education Ltd./ Pearson Prentice Hall, 12th ed., 2000, ISBN 0-582-41498-9

[krobison]

should also tack on alternatively polyadenylation, which is another route to generating alternative 3' UTRs which may have different biological properties.