|
An expressed sequence tag or EST is a short sub-sequence of a transcribed spliced nucleotide sequence (either protein-coding or not). They are intended as a way to identify gene transcripts, and are instrumental in gene discovery and gene sequence determination. The identification of ESTs has proceeded rapidly, with approximately 42 million ESTs now available in public databases (e.g. GenBank 3/2007, all species). A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...
A micrograph of ongoing gene transcription of ribosomal RNA illustrating the growing primary transcripts. ...
The GenBank sequence database is an annotated collection of all publicly available nucleotide sequences and their protein translations. ...
An EST is produced by one-shot sequencing of a cloned mRNA (i.e. sequencing several hundred base pairs from an end of a cDNA clone taken from a cDNA library). The resulting sequence is a relatively low quality fragment whose length is limited by current technology to approximately 500 to 800 nucleotides. Because these clones consist of DNA that is complementary to mRNA, the ESTs represent portions of expressed genes. They may be present in the database as either cDNA/mRNA sequence or as the reverse complement of the mRNA, the template strand. In genetics and biochemistry, sequencing means to determine the primary structure (or primary sequence) of an unbranched biopolymer. ...
The interaction of mRNA in a eukaryote cell. ...
In genetics, complementary DNA (cDNA) is single-stranded DNA synthesized from a mature mRNA template. ...
A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ...
Template strand is the strand of DNA that the RNA polymerase uses as a guide to build complementry mRNA. This is the complement of the Coding strand. ...
ESTs can be mapped to specific chromosome locations using physical mapping techniques, such as radiation hybrid mapping or FISH. Alternatively, if the genome of the organism that originated the EST has been sequenced one can align the EST sequence to that genome. A genetic map refers to the assignment of DNA fragments to chromosomes. ...
FISH (Fluorescent in situ hybridization) is a cytogenetic technique which can be used to detect and localize DNA sequences on chromosomes. ...
The current understanding of the human set of genes (2006) includes the existence of thousands of genes based solely on EST evidence. In this respect, ESTs become a tool to refine the predicted transcripts for those genes, which leads to prediction of their protein products, and eventually of their function. Moreover, the situation in which those ESTs are obtained (tissue, organ, disease state - e.g. cancer) gives information on the conditions in which the corresponding gene is acting. ESTs contain enough information to permit the design of precise probes for DNA microarrays that then can be used to determine the gene expression. A graphical representation of the normal human karyotype. ...
For the Manfred Mann album, see 2006 (album). ...
Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ...
Example of an approximately 40,000 probe spotted oligo microarray with enlarged inset to show detail. ...
Gene expression, or simply expression, is the process by which a genes DNA sequence is converted into the structures and functions of a cell. ...
Some authors use the term "EST" to describe genes for which little or no further information exists besides the tag[1]
References - ^ http://www.ncbi.nlm.nih.gov/dbEST/how_to_submit.html
External links |
Feeds |
Contact