Question

What are expressed sequence tags?

Answer 1

In the transcription process the DNA is converted to messenger RNA and this messenger RNA gets translated and forms a protein sequence. Three messenger RNA groups together code of specific amino acid that forms a amino acid chain of a protein.

Complete Answer:
- Many scientists are involved in sequencing the genomes of different organisms for many important projects. The main objective of any sequencing project is to find the genome sequence and determine the set of genes, and study about it and its expression, the whole process is termed as gene expression.
- If we can understand the expression of a gene's normal condition then we are able to understand the result of the alteration of that gene, like happens in many genetic disorders. There is one more study that is conducted by the scientist that is used to determine the location of the chromosomes of a specific gene termed linkage studies.
- If the location of the chromosome can be determined, the scientist uses biochemical methods for gene isolation and the corresponding proteins. These methods take a long time and also by these processes only a small percent of gene can be found and studied.
- Now, as a solution to this time consuming process, the expressed sequence tag method is introduced. This method helps the researchers by providing quick results. This method also involves obtaining gene expression data and regulation and gene mapping process.
- The expressed sequence tags are small DNA sequences that are formed by sequencing one or both the ends of an expressed gene. In this process the small DNA sequence is used as tags to fish a gene from the part of chromosomal DNA through base pair match.
- The limitation of this method varies from organism to organism but the common limitation is the presence and absence of introns.

Note: The limitation of this expressed sequence tag varies from organism to organism but the common limitation is the presence and absence of introns, as the introns presence in DNA sequence results in interruption in the protein coding sequence of a gene.