Somatic Mutation

somatic mutation

[sō¦mad·ik myü′tā·shən] (genetics) A genetic change limited to a somatic cell lineage; a major cause of cancer in humans.

Mutation, Somatic

a mutation that occurs in a somatic cell and provides the basis for a mosaic condition, that is, the formation of certain body parts, tissues, or cells having a unique set of chromosomes or genes.

All the types of somatic mutations that occur in sexual cells may occur in the cells of a developing organism. These mutations include (1) an increase in the chromosome set as a whole after normal chromosomal division without the subsequent division of the nucleus and cell, (2) trisomy and monosomy of various chromosomes as a result of the migration of two daughter chromosomes to a single pole (instead of different poles), and (3) the loss of a chromosome in one of the daughter cells during division as a result of its entrapment in the zone of the equatorial plate.

Inversions, deletions, and translocations of chromosomal fragments and mutations of individual genes occur with varying frequency in somatic cells. The earlier a somatic mutation occurs in an organism’s development, the greater the number of cells that will inherit the mutation, provided that the mutation does not destroy the carrier cell and that the rate of the carrier cell’s proliferation does not decrease. Gene somatic mutations are manifested relatively rarely, because in the overwhelming majority of cases the function of the mutant gene or of the separated chromosomal fragment is compensated for by the presence of a normal homologous gene or a normal area in the homologous matching chromosome of a mutant chromosome. The manifestation of certain somatic mutations is suppressed by the proximity of normal tissue.

Somatic mutations may not be manifested when the corresponding part of a chromosome of the given tissue is inactive. In the early 1960’s it was established that somatic mutations play an important role in the pathogenesis of the abnormal development of the sexual system, in the causation of spontaneous abortions and congenital deformities, and in carcinogenesis.

In plants, cells that carry somatic mutations may be propagated vegetatively or when the mutant area forms flowers.

REFERENCE

Vakhtin, Iu. B. Genetika somaticheskikh kletok. Moscow, 1974.

V. P. EFROIMSON

somatic mutation

mutation

[mu-ta´shun] 1. a permanent transmissible change in the genetic material.2. an individual exhibiting such a change.point mutation a mutation resulting from a change in a single base pair in the DNA molecule.somatic mutation a genetic mutation occurring in a somatic cell, providing the basis for mosaicism.suppressor mutation the correction of the effect of a mutation at one locus by a mutation at another locus.

so·mat·ic mu·ta·tion

a mutation occurring in the general body cells (as opposed to the germ cells) and hence not transmitted to progeny.

Acquired Mutation

Genetics A post-meiotic alteration in a DNA sequence, which can be passed to the mutated cell’s progeny and linked to the development of cancer.
Molecular biology A non-heritable genetic change in a somatic cell; a somatic mutation.

so·mat·ic mu·ta·tion

(sō-mat'ik myū-tā'shŭn) A change that occurs in the general body cells (as opposed to the germ cells) and hence not transmitted to progeny.

somatic mutation

A mutation affecting SOMATIC cells that can affect only those cells and their offspring, so cannot be passed on to future generations. Such a mutation dies with the death of the individual.

somatic mutation

see MUTATION.

单词	somatic mutation
释义	somatic mutation somatic mutation n (Botany) a mutation occurring in a somatic cell, resulting in a change in the morphology or some other aspect of one part of an organism (usually a plant). It may be maintained by vegetative propagation but not by sexual reproduction Translations Somatic Mutation somatic mutation [sō¦mad·ik myü′tā·shən] (genetics) A genetic change limited to a somatic cell lineage; a major cause of cancer in humans. Mutation, Somatic a mutation that occurs in a somatic cell and provides the basis for a mosaic condition, that is, the formation of certain body parts, tissues, or cells having a unique set of chromosomes or genes. All the types of somatic mutations that occur in sexual cells may occur in the cells of a developing organism. These mutations include (1) an increase in the chromosome set as a whole after normal chromosomal division without the subsequent division of the nucleus and cell, (2) trisomy and monosomy of various chromosomes as a result of the migration of two daughter chromosomes to a single pole (instead of different poles), and (3) the loss of a chromosome in one of the daughter cells during division as a result of its entrapment in the zone of the equatorial plate. Inversions, deletions, and translocations of chromosomal fragments and mutations of individual genes occur with varying frequency in somatic cells. The earlier a somatic mutation occurs in an organism’s development, the greater the number of cells that will inherit the mutation, provided that the mutation does not destroy the carrier cell and that the rate of the carrier cell’s proliferation does not decrease. Gene somatic mutations are manifested relatively rarely, because in the overwhelming majority of cases the function of the mutant gene or of the separated chromosomal fragment is compensated for by the presence of a normal homologous gene or a normal area in the homologous matching chromosome of a mutant chromosome. The manifestation of certain somatic mutations is suppressed by the proximity of normal tissue. Somatic mutations may not be manifested when the corresponding part of a chromosome of the given tissue is inactive. In the early 1960’s it was established that somatic mutations play an important role in the pathogenesis of the abnormal development of the sexual system, in the causation of spontaneous abortions and congenital deformities, and in carcinogenesis. In plants, cells that carry somatic mutations may be propagated vegetatively or when the mutant area forms flowers. REFERENCE Vakhtin, Iu. B. Genetika somaticheskikh kletok. Moscow, 1974. V. P. EFROIMSON somatic mutation mutation [mu-ta´shun] 1. a permanent transmissible change in the genetic material.2. an individual exhibiting such a change.point mutation a mutation resulting from a change in a single base pair in the DNA molecule.somatic mutation a genetic mutation occurring in a somatic cell, providing the basis for mosaicism.suppressor mutation the correction of the effect of a mutation at one locus by a mutation at another locus. so·mat·ic mu·ta·tion a mutation occurring in the general body cells (as opposed to the germ cells) and hence not transmitted to progeny. Acquired Mutation Genetics A post-meiotic alteration in a DNA sequence, which can be passed to the mutated cell’s progeny and linked to the development of cancer. Molecular biology A non-heritable genetic change in a somatic cell; a somatic mutation. so·mat·ic mu·ta·tion (sō-mat'ik myū-tā'shŭn) A change that occurs in the general body cells (as opposed to the germ cells) and hence not transmitted to progeny. somatic mutation A mutation affecting SOMATIC cells that can affect only those cells and their offspring, so cannot be passed on to future generations. Such a mutation dies with the death of the individual. somatic mutation see MUTATION. LegalSeeMutationThesaurusSeemutation
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