Sequencing and analysis of 10967 full-length cDNA clones from Xenopus laevis and Xenopus tropicalis
Year: 2005
Type: article
Abstract: Sequencing of full-insert clones from full-length cDNA libraries from both Xenopus laevis and Xenopus tropicalis has been ongoing as part of the Xenopus Gene Collection initiative. Here we present an analysis of 10967 clones (8049 from X. laevis and 2918 from X. tropicalis). The clone set contains 2013 orthologs between X. laevis and X. tropicalis as well as 1795 paralog pairs within X. laevis. 1199 are in-paralogs, believed to have resulted from an allotetraploidization event approximately 30 million years ago, and the remaining 546 are likely out-paralogs that have resulted from more ancient gene duplications, prior to the divergence between the two species. We do not detect any evidence for positive selection by the Yang and Nielsen maximum likelihood method of approximating d{sub N}/d{sub S}. However, d{sub N}/d{sub S} for X. laevis in-paralogs is elevated relative to X. tropicalis orthologs. This difference is highly significant, and indicates an overall relaxation of selective pressures on duplicated gene pairs. Within both groups of paralogs, we found evidence of subfunctionalization, manifested as differential expression of paralogous genes among tissues, as measured by EST information from public resources. We have observed, as expected, a higher instance of subfunctionalization in out-paralogs relative to in-paralogs.
Authors: Ryan D. Morin, Eun Jae Chang, Anca S. Petrescu, Nancy Liao, Russell Kirkpatrick, Marilyn Griffith, Yaron S.N. Butterfield, Jeff Stott, Sarah Barber, Ryan Babakaiff, Carmencita D. Padilla, Dominic W. S. Wong, Gangyi Yang, Duane E. Smailus, Mabel Brown-John, Michael Mayo, Jaclyn Beland, Susan I. Gibson, Teika Olson, Ming‐An Tsai, Ruth Featherstone, Steve Chand, Asim Siddiqui, Wonhee Jang, E Lee, Steven L. Klein, Christa Prange, R Myers, E D Green, Lukas Wagner, Daniela S. Gerhard, Maria Luisa Marra, Scott Jones, Robert A. Holt
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W87513540