Gene duplication

Gene duplication referred to in genetics doubling of a particular section of a chromosome, ie the permanent doubling (up to multiplication ) of individual genes or gene groups (followed by separate development). This type of genetic mutation occurs, for example by unequal crossing over between either homologous chromosomes or between sister chromatids. A distinction is made between partial and complete gene duplication. The chromosome DNA matrix becomes larger, longer. The original and the resulting doubling of its gene are in the ratio of paralogy, they are each other paralog.

This mutation can not be resolved by our own repair mechanisms and performs the serious change in the gene sequence common to congenital defects in the rule. The gene duplication is also true as an essential mechanism of evolution. Mutations of the gene copy functionally new genes can arise and the spectrum of the original gene activity to be extended. For example, the man was only through gene duplication of the L- pin for trichromats, which enables him to perceive colors. Another example is the family of hemoglobins, with different affinities for oxygen. From gene duplications but can also arise pseudogenes. Numerous gene duplications (eg olfactory receptor genes ) are in the genomes of various people before in various forms and frequency and form so-called Gene copy number variants ( copy number variants).