Use of ESTs

Sequencing an EST library is a relatively inexpensive and quick way to generate a lot of sequence information in cases where whole genome sequencing is not possible.

Since ESTs are generated from cDNA, they are highly likely to represent genic regions of the genome.

ESTs can be used directly as markers and mapped to a chromosomal location just like any other marker (see de Vicente and Fulton, 2002 for more on molecular markers).

However, they are especially useful in the hunt for genes, as they greatly reduce the time and expense of the search.

A particular advantage of ESTs is that, if there is a large enough set of them, overlaps can be used to assemble larger sequences called ‘contigs', which can sometimes be extensive enough to recreate the whole gene.

 

 

Overlapping EST sequences can be computationally ordered into one long sequence, a contig.

Thus ESTs have many uses, some of which are:

- Discovering new genes.

- Confirming coding regions of genomic sequence.

- Studying phylogenetic relationships.

- Developing genome maps.

- Producing expression arrays.