[ Back to EurekAlert! ] Public release date: 2-Apr-2007
[ | E-mail Share Share ]

Contact: Natalie Bouaravong
press@plos.org
415-568-3445
Public Library of Science

Bony vertebrate evolution: Elephant sharks closer to humans than teleost fish

Cartilaginous fishes (sharks, rays, skates, and chimaeras) are the phylogenetically oldest group of living jawed vertebrates. They are also an important outgroup for understanding the evolution of bony vertebrates such as human and teleost fishes. In a new study published online this week in the open access journal PLoS Biology, Byrappa Venkatesh, Sydney Brenner, and colleagues performed survey sequencing (1.4× coverage) of a chimaera, the elephant shark (Callorhinchus milii).

The elephant shark genome, estimated to be about 910 Mb long, comprises about 28% repetitive elements. Comparative analysis of approximately 15,000 elephant shark gene fragments revealed examples of several ancient genes that have been lost differentially during the evolution of human and teleost fish lineages. Interestingly, the human and elephant shark genomes exhibit a higher degree of synteny and sequence conservation than human and teleost fish (zebrafish and fugu) genomes, even though humans are more closely related to teleost fishes than to the elephant shark. Unlike teleost fish genomes, the elephant shark genome does not seem to have experienced an additional round of whole-genome duplication. These findings underscore the importance of the elephant shark as a useful "model" cartilaginous fish genome for understanding vertebrate genome evolution.

###

Citation: Venkatesh B, Kirkness EF, Loh YH, Halpern AL, Lee AP, et al. (2007) Survey sequencing and comparative analysis of the elephant shark (Callorhinchus milii) genome.
PLoS Biol 5(4): e101. doi:10.1371/journal.pbio.0050101.

CONTACT:
Byrappa Venkatesh
Institute of Molecular and Cell Biology
61 Biopolis Drive
Singapore, 138673
Singapore
65 - 6586 9571
65 - 6779 1117 (fax)
mcbbv@imcb.a-star.edu.sg

PLEASE MENTION THE OPEN-ACCESS JOURNAL PLoS BIOLOGY (www.plosbiology.org) AS THE SOURCE FOR THESE ARTICLES AND PROVIDE A LINK TO THE FREELY-AVAILABLE TEXT. THANK YOU.

All works published in PLoS Biology are open access. Everything is immediately available—to read, download, redistribute, include in databases, and otherwise use—without cost to anyone, anywhere, subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.



[ Back to EurekAlert! ] [ | E-mail Share Share ]

 


AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.