Expressed sequence tag (EST)

Definition

An expressed sequence tag (EST) is a short sub-sequence of a cDNA sequence that represents a fragment of an expressed gene. ESTs are used in locating and identifying gene transcripts in genome mapping and sequencing projects.

5 Must Know Facts For Your Next Test

1. ESTs are derived from mRNA, indicating they represent parts of genes that are actively expressed.
2. They are used to identify gene transcripts and provide information on gene expression patterns.
3. EST databases help in annotating genomes by matching EST sequences to genomic DNA.
4. The generation of ESTs involves reverse transcription of mRNA into cDNA followed by sequencing.
5. They can be used to find homologous genes across different species, aiding comparative genomics.

Review Questions

Related terms

cDNA: Complementary DNA synthesized from an mRNA template using reverse transcriptase.

Genomic DNA: The complete set of DNA in an organism, including both coding and non-coding regions.

Comparative Genomics: The study of similarities and differences between the genomes of different species.