The post-genomics era aims at the complete
characterization of cells at all levels
Knowing the complete genome sequence of any
organism is very useful, but more important is finding the genes and determining their functions.
One of the most surprising results from the early
genome projects was the discovery of how little was
known about even the best-characterized organisms. In the case of the bakers’ yeast (S. cerevisiae),
which was considered a very well-characterized
model species, only one-third of the genes identified
in the sequencing project had been identified before.
Over 4000 genes were discovered with no known
function. Some of these could be assigned tentative
functions on the basis of similarity to known genes
either in the yeast or in other organisms, but this still
left over 2000 genes whose function could only be
established by direct experiments.