Functional Genomics by Gene-Trapping in Embryonic Stem Cells

The pace of sequencing whole genomes by far exceeds our increase of knowledge on gene functions. Twenty-two genomes have been already completed and both the human and mouse genome are close to be completed as well. The number of sequences in the National Center for Biotechnology Information (NCBI) gene bank doubles approximately every other 15 months (1 ). The gain of information on expressed sequence tags (ESTs) from a multiplicity of organisms and cell types rose exponentially and is close to reaching saturation.