Simple Sequence Length Polymorphisms (SSLPs) are used as
genetic marker A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can be ...
s with
polymerase chain reaction (PCR)
The polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies (complete or partial) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) ...
. An SSLP is a type of
polymorphism
Polymorphism, polymorphic, polymorph, polymorphous, or polymorphy may refer to:
Computing
* Polymorphism (computer science), the ability in programming to present the same programming interface for differing underlying forms
* Ad hoc polymorphis ...
: a difference in
DNA sequence amongst individuals. SSLPs are repeated sequences over varying base lengths in intergenic regions of deoxyribonucleic acid (DNA). Variance in the length of SSLPs can be used to understand
genetic variation
Genetic variation is the difference in DNA among individuals or the differences between populations. The multiple sources of genetic variation include mutation and genetic recombination. Mutations are the ultimate sources of genetic variation, b ...
between two individuals in a certain species.
Applications
An example of the usage of SSLPs (
microsatellites) is seen in a study by Rosenberg et al., where SSLPs were used to cluster different continental populations of human beings.
The study was critical to
Nicholas Wade's New York Times Bestseller, ''
Before the Dawn: Recovering the Lost History of Our Ancestors''.
[Wade, Nicholas (2006). ''Before the Dawn: Recovering the Lost History of Our Ancestors''. Penguin Press. ]
Rosenberg Study
Rosenberg studied 377 SSLPs in 1000 people in 52 different regions of the world. By using
PCR PCR or pcr may refer to:
Science
* Phosphocreatine, a phosphorylated creatine molecule
* Principal component regression, a statistical technique
Medicine
* Polymerase chain reaction
** COVID-19 testing, often performed using the polymerase chain r ...
and
cluster analysis
Cluster analysis or clustering is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense) to each other than to those in other groups (clusters). It is a main task of ...
, Rosenberg was able to group individuals that had the same SSLPs . These SSLPs were extremely useful to the experiment because they do not affect the
phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological prop ...
s of the individuals, thus being unaffected by
natural selection
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Cha ...
.
[{{cite journal , last=Rosenberg , first=N. A. , title=Genetic Structure of Human Populations , journal=Science , publisher=American Association for the Advancement of Science (AAAS) , volume=298 , issue=5602 , date=2002-12-20 , issn=0036-8075 , doi=10.1126/science.1078311 , pages=2381–2385 , pmid=12493913, bibcode=2002Sci...298.2381R , s2cid=8127224 ]
References
Polymorphism (biology)