Gene Expression

Some genes have house-keeping functions and are found in many tissues. Other genes have very specific functions and are only found in certain areas; it is this property we capitalise on for our Gene Expression Mappings.

By querying a gene expression database we aim to identify the genes expressed in each tissue of an organism (the tissues in the organism already having been gained by searching the anatomy database).

The SWISSPROT/TrEMBL composite provides the protein sequence for each gene. Running BLAST on these sequences gives a list of genes in different species which are equivalent.
	If we can then find a pair of tissues which share a high number of equivalent genes we can then make an assumption that those tissues are equivalent.