Comparative genomics provides evidence for an ancient genome duplication event in fish

• DOI: 10.1098/rstb.2001.0975
• Publication Date: 2002-07-26T23:57:15Z
• Authors: John S. Taylor; Yves Van de Peer; Ingo Braasch; Axel Meyer
• Keywords: Oryzias; Fugu; Danio; Comparative Genomics

There are approximately 25 000 species in the division Teleostei and most believed to have arisen during a relatively short period of time ca. 200 Myr ago. The discovery ‘extra’ Hox gene clusters zebrafish ( Danio rerio ), medaka Oryzias latipes pufferfish Fugu rubripes has led hypothesis that genome duplication provided genetic raw material necessary for teleost radiation. We identified 27 groups orthologous genes which included one from man, mouse chicken, or two tetraploid Xenopus zebrafish. A ancestor fishes is parsimonious explanation observations 15 these genes, orthologues sister sequences phylogenies otherwise match expected organismal tree, pairs appear been formed at same time, unlinked. Phylogenies nine differ little tree predicted by fish–specific hypothesis: shows sequence relationship but differs slightly eight trees, clade includes second , man. For deviations predictions poorly supported. each three remaining tightly linked are, therefore, unlikely event. estimated unlinked duplicated between 300 450 Myr. Thus, could Alternatively, loss different duplicates populations (i.e. ‘divergent resolution’) may promoted speciation ancient populations.