DNA patent Genes are located on chromosomes in the nucleus of a cell and are made of deoxyribonucleic acid (“DNA”). DNA is composed of two strands of nucleotides in double helix formation. The nucleotides contain one of four bases, adenine (“A”), guanine (“G”), cytosine (“C”), and thymine (“T”), that are linked by hydrogen bonds to form complementary base pairs (i.e., A-T and G-C). When a gene is expressed in a cell, the relevant double-stranded DNA sequence is transcribed into a single strand of messenger ribonucleic acid (“mRNA”). Messenger RNA contains three of the same bases as DNA (A, G, and C), but contains uracil (“U”) instead of thymine. mRNA is released from the nucleus of a cell and used by ribosomes found in the cytoplasm to produce proteins. Complementary DNA (“cDNA”) is produced synthetically by reverse transcribing mRNA. cDNA, like naturally occurring DNA, is composed of nucleotides containing the four nitrogenous bases, A, T, G, and C. Scientists routinely compile cDNA into libraries to study the kinds of genes expressed in a certain tissue at a particular point in time. One of the goals of this research is to learn what genes and downstream proteins are expressed in a cell so as to regulate gene expression and control protein synthesis.2 An EST is a short nucleotide sequence that represents a fragment of a cDNA clone. It is typically generated by isolating a cDNA clone and sequencing a small number of nucleotides located at the end of one of the two cDNA strands. When an EST is introduced into a sample containing a mixture of DNA, the EST may hybridize with a portion of DNA. Such binding shows that the gene corresponding to the EST was being expressed at the time of mRNA extraction.
Posted on: Tue, 05 Nov 2013 18:01:38 +0000
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