Satellite DNA

- Satellite DNA consists of highly repetitive DNA, and is so called because repetitive DNA sequences tend to have a relatively high frequency of the nucleotides Adenine and Thymine, and thus have lower density - such that they form a second 'satellite' band when genomic DNA is separated along a density gradient.
Definition from:
"Satellite DNA." Wikipedia, The Free Encyclopedia

- A portion of the DNA that differs enough in base composition so that it forms a distinct band on cesium chloride gradient centrifugation; usually contains highly repetitive DNA sequences
Definition from:
http://www.kumc.edu/gec/gloss.html

- DNA that forms a separate band in a bouyant density gradient because of its different nucleotide composition (A:T rich DNAs are less dense than G:C rich DNAs). Highly repetitive eukaryotic DNA primarily located around centromeres. Satellite DNA usually has a different buoyant density than the rest of the cell's DNA.
Definition from:
http://www.biochem.northwestern.edu/holmgren/Glossary/Definitions/Def-S/satellite_DNA.html

SCAR ( Sequence characterised amplified region )

- A locus representing a single RAPD fragment which has been sequenced. Primers specific to the locus can be designed and used in PCR amplification.
Definition from:
Hypermedia Glossary Of Genetic Terms

SINE ( Short interspersed element )

- A type of small dispersed repetitive DNA sequence (eg Alu family in the human genome) found throughout a eukaryotic genome.
Definition from:
http://www.biochem.northwestern.edu/holmgren/Glossary/Definitions/Def-S/SINE.html

SNP ( Single nucleotide polymorphism )

- Sequence polymorphism differing in a single base pair.
Definition from:
Hypermedia Glossary Of Genetic Terms

- A type of polymorphism in which two chromosomes differ in a given segment by the identity of a single base pair.
Definition from:
Mouse Genome Informatics

- DNA sequence variations that occur when a single nucleotide (A, T, C, or G) in the genome sequence is altered. Each individual has many single nucleotide polymorphisms that together create a unique DNA pattern for that person. SNPs promise to significantly advance our ability to understand and treat human disease.
Definition from:
http://www.biochem.northwestern.edu/holmgren/Glossary/Definitions/Def-S/SNP.html

spacer DNA

- Regions of non-transcribed DNA between transcribed repeated genes such as ribosomal RNA genes in eukaryotes. Its function is probably to do with ensuring the high rates of transcription associated with these genes.
Definition from:
http://www.biochem.northwestern.edu/holmgren/Glossary/Definitions/Def-S/spacer_DNA.html

SPAR ( Single primer amplification reaction )

- A PCR technique using core motifs of microsatellite DNA
Definition from:
Hypermedia Glossary Of Genetic Terms

SSCP ( Single stranded conformational polymorphism )

- A method for distinguishing between similar sized DNA fragments according to the mobility of the single-stranded DNA under polyacrylamide gel electrophoresis
Definition from:
Hypermedia Glossary Of Genetic Terms

- A type of mutation scanning; the identification of abnormally migrating single-stranded DNA segments on gel electrophoresis
Definition from:
Genetests

STMS (Sequence tagged microsatellite)

- Primers constructed from the flanking regions of microsatellite DNA which can be used in PCR reactions to amplify the repeat region.
Definition from:
Hypermedia Glossary Of Genetic Terms
 

STR ( Short Tandem Repeats  )

- Multiple copies of an identical DNA sequence arranged in direct succession in a particular region of a chromosome.
Definition from:
Genetics/DNA Glossary

STS ( Sequence tagged site )

- Any site in a chromosome or genome that is identified by a known unique DNA sequence. STSs can be used to form genetic maps by standard mapping procedures
Definition from:
http://www.biochem.northwestern.edu/holmgren/Glossary/Definitions/Def-S/sequence_tagged_site.html

- A short segment of unique sequence derived from genomic DNA. A large collection of STSs can be used to assemble a physical map of the genome from a collection of genomic clones (e.g., BACs or YACs) by testing each clone for the presence of each STS. Two clones that contain one or more STSs in common must overlap
Definition from:
Mouse Genome Informatics

- Short (200 to 500 base pairs) sequence of genomic DNA that has a single occurrence in the human genome and whose location and base sequence are known. Detectable by polymerase chain reaction, STSs are useful for localizing and orienting the mapping and sequence data reported from many different laboratories and serve as landmarks on the developing physical map of the human genome.
Definition from:
Hypermedia Glossary Of Genetic Terms

Substitution

- In genetics, a type of mutation due to replacement of one nucleotide in a DNA sequence by another nucleotide or replacement of one amino acid in a protein by another amino acid.
Definition from:
Genome Glossary