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Mutant
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Mutant
A mutant is an individual, organism, or new genetic character arising or
resulting from an instance of mutation, which is a sudden structural
change within the DNA of a gene or chromosome of an organism resulting
in the creation of a new character or trait not found in the wildtype.
In an organism or individual, the new character or trait may or may not
be trivial, may occasionally be beneficial, but will usually result in
either a genetic disorder or have no phenotypic effect whatsoever. The
natural occurrence of genetic mutations is integral to the process of
evolution. A more general term for mutant is sport, which includes
individuals who vary from type due to mutation, as well as those who
vary from type due to other reasons.
Developmental abnormalities not due to genetic change, are frequently
referred to as mutants by non-experts. The difference between a
developmental abnormality and a mutation is that the former is
non-hereditable as the DNA is unchanged. Such abnormalities include
extra limbs and occur when a genetically normal embryo develops
abnormally.
Occasionally, a body cell in a healthy organism may acquire a mutation
caused by a genetic error occurring during routine cell division. This
is also known as a "somatic mutation." Such an error may result in
cancer.
Creatures with visibly obvious mutations are often regarded as objects
of curiosity. Examples include rare blue lobsters.[1] albinos of many
species[2][3] and animals with extra digits.[4] A well-known mutation in
fruit flies causes the flies to have legs in place of antennas.[5] An
American aquarium even displays what it calls a "double mutant" snake
that is both albino and has two heads[6], though calling this a double
mutation is a misnomer as the two-headed condition is a developmental
abnormality and not a genetic mutation.
Similarly striking human mutations also occur occasionally. People who
are completely covered in a fur-like coat of hair are one example (see
hypertrichosis). There are also cases of newborn babies having an
extended tailbone or a sixth finger. Purely internal, less obvious
mutations are more common; a small fraction of these cause serious
medical conditions or death. (The ratio is probably under 1.5%, as only
about 1.5% of the genome encodes protein genes)[7]
Wild type
Wild type (sometimes written wildtype, wild-type or +) is the genetic
term used in texts for the typical form of an organism, strain, gene, or
characteristic as it was first observed in nature. [8][9]. Wild type
refers to the most common phenotype in the natural population, however
this may, over a period of time, be replaced by a mutant form, which
then becomes the new wildtype. The phenotype can be dominant or
recessive. Naturally occurring mutant phenotypes play a role in
evolution.
References
1. ^ WESH NBC affiliate news report
2. ^ Picture of Snowflake, a white ape
3. ^ Pictures of albino (and other) reptiles
4. ^ Polydactyly, pictured in cats
5. ^ Memorial University of Newfoundland page with picture, paragraph
about antennapedia mutant flies
6. ^ BBC news report World Aquarium in St. Louis auctioning its albino
two-headed rat snake. (The snake did not fetch enough money and was
ultimately not sold)].
7. ^ International Human Genome Sequencing Consortium (2001). "Initial
sequencing and analysis of the human genome.". Nature 409 (6822):
860-921. PMID 11237011. [1]
8. ^ Robinson Roy (1999), "Genetics for Cat Breeders and Veterinarians",
Butterworth Heinemann, ISBN 0-7506-4069-3
9. ^ http://helios.bto.ed.ac.uk/bto/glossary/tuvwxyz.htm
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