Gene annotation: be careful!

Many sequences in genomic databases are associated with a function, via a process known as annotation. However, most gene functions have yet to be validated experimentally - rather, they are assumed on the basis of sequence similarity.

Remember - annotated function is only a (well informed) guess.

For example, the figure below shows a blast result of a tomato EST sequence (SGN-E247181). Note the phrase “similar to cell division control protein” (in rice). This tomato sequence may or may not turn out to actually have this function - it may be a good place for an interested researcher to start investigating, but at this point it is not known.