Accelerated Gene Evolution and Subfunctionalization in the Pseudotetraploid Frog Xenopus Laevis Page: 4 of 50
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
Gene duplication followed by subsequent functional divergence is widely
recognized as an important mechanism for the evolution of novelty [1,2]. On a
small scale, local tandem duplications can rapidly produce new gene families,
such as the Hox cluster in animals , the olfactory receptors in vertebrate
genomes , and numerous other examples in plants [5,6], protists  and other
lineages. Recently duplicated genes have a strong tendency to become
pseudogenes, and will generally be lost due to disabling mutations unless
positive selection preserves the duplicate loci. Based on the divergence of
surviving gene pairs in diverse genomes, the typical lifetime of duplicated genes
in a diploid background has been estimated to be several million years .
On a grander scale, entire genomes can be duplicated by polyploidization so that
the cells of the resulting organism find themselves with two copies of every gene.
Again, there is presumably a strong tendency towards rapid differential loss due
to mutation of superfluous copies, and the long-term effect on the genome is
elimination of most of the duplicate loci . In the case of polyploidy, the
population dynamic and stoichiometric effects are different from the case of a
localized duplication in a diploid background. Loss of a copy of a locally-
duplicated gene simply restores the pre-duplication genome. In contrast, in the
case of whole genome duplication the polyploid population is presumably
reproductively isolated from its diploid brethren, and inactivation/loss of one of a
pair of duplicate sequences puts that gene at half the copy number of the
Here’s what’s next.
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Hellsten, Uffe; Khokha, Mustafa K.; Grammar, Timothy C.; Harland,Richard M.; Richardson, Paul & Rokhsar, Daniel S. Accelerated Gene Evolution and Subfunctionalization in the Pseudotetraploid Frog Xenopus Laevis, article, March 1, 2007; Berkeley, California. (https://digital.library.unt.edu/ark:/67531/metadc886588/m1/4/: accessed April 22, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.