Comparative and Functional Genomics
Volume 2008 (2008), Article ID 545269, 11 pages
doi:10.1155/2008/545269
Research Article
Tandemly Arrayed Genes in Vertebrate Genomes
1Department of Computer Science, Virginia Tech, 2050 Torgerson Hall, Blacksburg, VA 24061-0106, USA
2Program in Genetics, Bioinformatics, and Computational Biology, Virginia Tech, 2050 Torgerson Hall, Blacksburg, VA 24061-0106, USA
Received 24 January 2008; Accepted 17 August 2008
Academic Editor: Jeffrey Bennetzen
Copyright © 2008 Deng Pan and Liqing Zhang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Tandemly arrayed genes (TAGs) are duplicated genes that are linked as neighbors on a chromosome, many of which have important
physiological and biochemical functions. Here we performed a survey
of these genes in 11 available vertebrate genomes. TAGs account for
an average of about 14% of all genes in these vertebrate genomes, and
about 25% of all duplications. The majority of TAGs (72–94%) have
parallel transcription orientation (i.e., they are encoded on the same strand) in contrast to the genome, which has about 50% of its genes
in parallel transcription orientation. The majority of tandem arrays
have only two members. In all species, the proportion of genes that
belong to TAGs tends to be higher in large gene families than in small
ones; together with our recent finding that tandem duplication played
a more important role than retroposition in large families, this fact
suggests that among all types of duplication mechanisms, tandem duplication
is the predominant mechanism of duplication, especially in
large families. Finally, several species have a higher proportion of large
tandem arrays that are species-specific than random expectation.