Nevertheless, the data show that the aquaporin grades independently expanded by
gene duplication in the different lineages.
Gene duplication is considered a major driving force for evolution of genetic novelty, thereby facilitating functional divergence and organismal diversity, including the process of speciation.
The dosage effect model implies that paralogs are subject to purifying selection from the onset of evolution after the
gene duplication [3, 7] whereas the DDC model assumes "constructive neutral evolution" [14] whereby the paralogs are maintained due to the partial, differential degeneration of their functions resulting in functional complementarities [2, 6, 35].
Increased incidence of CYP2D6
gene duplication in patients with persistent mood disorders: ultrarapid metabolism of antidepressants as a cause of nonresponse.
The other Brachypodium COMT genes are likely to be paralogs of BdCOMT4, resulting from
gene duplications and translocations into different locations.
Evolution By
Gene Duplication. SpringerVerlag, Berlin and New York.
These include insertion of repeat sequences, change in expression profile,
gene duplication, gene fusion and gene loss or inactivation (9).
About 1,200 different protein domains are known; they are used in many different combinations, thus defining many gene families that developed through
gene duplication. In homologous genes of different species, often only the sequences coding for these very domains are preserved.
Gene duplication event in family 12 glycosyl hydrolase from Phytophthora spp.
Gene duplication in 1 allele was later confirmed by the finding that 17-OH progesterone concentrations were within the reference interval in the amniotic fluid and by fetal echography showing ordinary female external genitalia.
The Sad2 gene has evolved from the most ancient and highly conserved cytochrome P450 family by
gene duplication and then diverged from its original role in making sterols to adopt a new function producing an antimicrobial chemical called avenacin.
In one daughter lineage,
gene duplication and selection achieved a new balance to develop a complex organ like an eye out of that inherent potential.