Blog

cDNA libraries have been broadly used to determine the expressed portion of protein-coding genes in eukaryotes. The construction of a cDNA library involves the extraction and purification of mRNA (Fig. 2.8).

A contig--from the word "contiguous"--is a series of overlapping DNA sequences used to make a physical map that reconstructs the original DNA sequence of a chromosome or a region of a chromosome.

Sequence annotation is the process of marking specific features in a DNA, RNA or protein sequence with descriptive information about structure or function.

The sequencer generates about 500 to 800 base pairs of A, T, C and G from each sequencing reaction, so that each base is sequenced about 10 times. A computer then assembles these short sequences into contiguous stretches of sequence representing the human DNA in the BAC clone.

• Expressed sequence tags (ESTs) are fragments of mRNA sequences derived through single sequencing reactions performed on randomly selected clones from cDNA libraries. To date, over 45 million ESTs have been generated from over 1400 different species of eukaryotes. For the most part, EST projects are …

• Expressed sequence tags (ESTs) are relatively short DNA sequences (usually 200–300 nucleotides) generally generated from the 3′ ends of cDNA clones from which PCR primers can be derived and used to detect the presence of the specific coding sequence in genomic DNA. From: Encyclopedia of Genetics, 2001

• 11.2.1.1 Expressed sequence tag analysis Expressed sequence tags (ESTs) are randomly selected clones sequenced from cDNA libraries. Each cDNA library is constructed from total RNA or poly (A) RNA derived from a specific tissue or cell, and thus the library represents genes expressed in the original cellular population.

• ESTs are basically short DNA sequences (cistron) randomly selected from the genome library. ESTs are usually 100 to 800 nucleotides long and produced by sequencing specific coding gene without introns (cDNA). The presence of introns makes gene identification quite difficult.

Expressed sequence tags (ESTs) are fragments of mRNA sequences derived through single sequencing reactions performed on randomly selected clones from cDNA libraries. To date, over 45 million ESTs have been generated from over 1400 different species of eukaryotes. For the most part, EST projects are …

Expressed sequence tags (ESTs) are relatively short DNA sequences (usually 200–300 nucleotides) generally generated from the 3′ ends of cDNA clones from which PCR primers can be derived and used to detect the presence of the specific coding sequence in genomic DNA. From: Encyclopedia of Genetics, 2001

ESTs are basically short DNA sequences (cistron) randomly selected from the genome library. ESTs are usually 100 to 800 nucleotides long and produced by sequencing specific coding gene without introns (cDNA). The presence of introns makes gene identification quite difficult.

A Sequence Tagged Site (STS) is a short DNA sequence that is easily recognizable and occurs only once in a genome (or chromosome). The 3' ESTs serve as a common source of STSs due to their likelihood of being unique to a particular species, and provide the additional feature of pointing directly to an expressed gene.