Polymorphism repeating unit

Microsatellites-the repeated units are typically 2-4 bp, and the length of the entire repeat is generally less than 150 bp. This dass often referred to as STRs (simple tandem repeats) is most typically amplified by a PCR for paternity testing, forensic cases, or gene linkage analysis (see Section II, Chapter 4 Polymorphic Markers and Linkage Analysis). 

VNTRs (variable number of tandem repeats). These polymorphisms are the result of varying numbers of minisatellite repeats in a specific region of a chromosome. The repeat units typically range in size from 20 to 70 bases each. The repeat is flanked on both sides by a restriction site, and variation in the number of repeats produces restriction fragments of varying size. 

There are two polymorphic structures of ZnS, zinc blende (or sphalerite) (3 2PT) and wurtzite (2 2PT). In zinc blende there is a ccp arrangement of S atoms with Zn atoms filling one of the two T layers as shown in Figure 6.1. The diamond has the same structure, with the sites of P and one T layer filled by C atoms (Section 4.3.3). The structure of zinc blende has six (3 2) layers in the repeating unit. This structure is encountered for many binary compounds with significant covalent character as shown in Table 6.1. The space group for zinc blende is T%, F43m, and a0 = 5.4093 A, for the cubic unit cell. ... 

D1S80 maps chromosome 1 and has a tandem repeat unit of 16 base pairs, which confers on this locus a large repeat unit polymorphism. McCord et al. (1993a) reported the successful resolution of a mixture of standard D1S80 alleles, spanning from 403 to 1069 bp they used 0.635 m M ethidium bromide... 

There are several major types of DNA sequence variation in the human genome. One type comprises repeated sequences with variations in the number of repeat units, such as short tandem repeat polymorphisms (STRPs, also known as microsatellites) in the form of mono-, di-, tri-, and tetra-nu-cleotide repeats, or more complex sequence repeats such as variable number tandem repeats (VNTRs) [2-4]. Repeat polymorphisms are relatively... 

Jeffreys, A.J., R. Neumann and V. Wilson 1990 Repeat unit sequence variation in minisatellites a novel source of DNA polymorphism for studying variation and mutation by single molecule analysis. Cell 60 475-485>... 

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