Glossary Term
Deoxyribonucleotide Triphosphate
A nucleotide comprised of either a purine or pyrimidine nitrogenous base bound to a deoxyribose sugar esterified with three phosphate groups. These molecules are essential for DNA synthesis.
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Glossary Term
A nucleotide comprised of either a purine or pyrimidine nitrogenous base bound to a deoxyribose sugar esterified with three phosphate groups. These molecules are essential for DNA synthesis.
Glossary Term
Nucleotide Excision Repair (NER) mends DNA regions that contain chemical adducts, such as UV-induced thymine dimers or carcinogenic adducts, which distort the DNA helix and interfere with replication and transcription. NER is targeted to actively transcribed regions of the genome. During NER in eukaryotes, shape irregularities are detected by protein complexes that slide along the DNA molecule and induce cuts on each side of a lesion several nucleotides away. Removal of the damaged 25-30 nucleotide fragment is followed by repair synthesis and ligation.
Glossary Term
A DNA polymer made up of a small number of nucleotides.
Glossary Term
A variation of a single nucleotide at a specific location of the genome due to base substitution, present at an appreciable frequency between individuals of a single interbreeding population.
Glossary Term
A variation of a single nucleotide at a specific location of the genome due to base substitution, which is found at any frequency in the population.
Glossary Term
A subunit of DNA or RNA consisting of a nitrogenous base (adenine, guanine, thymine, or cytosine in DNA; adenine, guanine, uracil, or cytosine in RNA), a phosphate molecule, and a sugar molecule (deoxyribose in DNA and ribose in RNA).
Technology
A DNA sequencing technique that can differentiate cytosine from 5-methylcytosine in a DNA sample. First, a denatured DNA sample is treated with bisulfite which converts non-methylated cytosine to uracil. Next, the sample is amplified using a PCR method that does not discriminate between non-methylated and methylated sequences. The amplified DNA is subjected to nucleotide sequencing. The resulting sequence is compared to an identical control sample of DNA that was not treated with bisulfite. Unmethylated cytosines will be displayed as cytosines in the control sample and as thymines in the bisulfite-treated sample.
Technology
A type of high-throughput, multiplex PCR method used to determine abnormal DNA copy number changes of up to 50 genomic DNA or RNA sequences with a single pair of PCR primers. It is frequently used in the detection of genetic aberrations in tumors, and can distinguish sequences differing in only a single nucleotide.
Technology
Technologies that facilitate the rapid determination of the nucleotide sequence of large numbers of strands or segments of DNA or RNA.
Technology
A technique that determines the nucleotide sequence of a pre-specified region of DNA or RNA by using primers that are specific for that region.
Technology
A procedure that can determine the nucleotide sequence for all of the RNA transcripts in an amplified nucleotide sample that was derived from a single cell.
Technology
A procedure used to demonstrate nucleotide sequence variations that occur in the same region of DNA between individuals within a species, or between alleles in an individual to detect mutations in various genes, such as oncogenes, tumor suppressor genes, or genes responsible for genetic diseases. The method detects different conformations adopted by partially denatured DNA fragments resulting from their specific nucleotide sequences under denaturing conditions. Denatured single-stranded DNA fragments are allowed to partially renature without formation of double-stranded DNA. The particular conformations adopted by each of the renatured fragments depend on each of their specific nucleotide sequences. The fragments are run on polyacrylamide gels to detect subtle changes in migration due to their particular secondary structures. Resulting fragment band in the gel will misalign if any point mutations are present to alter the conformation.