In genetics, an expressed sequence tag (EST) is a short sub-sequence of a cDNA sequence. ESTs may be used to identify gene transcripts, and are instrumental in gene discovery and in gene-sequence determination.
EST as a molecular tag expressed region of a gene located by the coding DNA sequence is highly conserved and has its own special properties of the tag (e.g., from non-expression of a sequence
of AFLP
,
of RAPD
more likely to cross the limit families and species compared, SSR, etc.), thus EST tag comparison between distantly related species
genome
linkage maps
and Comparative
trait quality
information is particularly useful. Similarly, a DNA sequence for the target species lacking, an EST derived from other species can also be useful for the gene of the species
genetic mapping
, rapidly accelerated conversion related information among species.
In particular, the performance in the role EST:
⑴ to construct a genetic map with the genome of the
physical maps
;
⑵ as probes for
radioactive
hybridization;
⑶ for
positional cloning
;
⑷ so as to find new genes;
⑸ as
molecular marker
;
⑹ to study biological population
polymorphism
;
⑺ used to study the function of genes;
⑻ contribute to the development, improvement of varieties of drugs;
⑼ promoting
gene chip
aspects of development and so on. It is because of these EST showed great potential, it has been fully utilized and development.