1. Genetic markers and their detection
Genetic markers and their detection. Four major types of genetic markers used for genetic mapping are depicted, along with the experimental method used for their detection. Restriction fragment length polymorphisms (RFLPs) are typically associated with the variable presence of a restriction site(s) (indicated by vertical arrows) in a stretch of DNA and are detected by restriction digestion, Southern blotting, and hybridization with a suitable probe. Variable numbers of tandem repeats (VNTR markers) reflect variable sizes of DNA tracts harboring a repeated DNA segment, again typically detected by digestion with a restriction enzyme, Southern blotting, and hybridization with a probe. Short tandem repeat (STR) markers consist of smaller simple-sequence (e.g., di-, tri-, or tetranucleotide) repeats, which can be detected by polymerase chain reaction (PCR) with primers (depicted as horizontal arrows) that flank the repeated region (see Fig. 10-9). Single nucleotide polymorphisms (SNPs) reflect differences of a single nucleotide at a defined position (shown here as a C vs A) and are typically detected by PCR amplification of the DNA segment harboring the polymorphism, followed by an analytical step that enables discrimination between the different sequences. (Adapted from Rossiter and Caskey.475 Used by permission.)
Source: The Human Genome Project and Its Impact on the Study of Human Disease, The Online Metabolic and Molecular Bases of Inherited Disease
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular Bases of Inherited Disease; 2014 Available at: Accessed: November 09, 2017
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