The 2R hypothesis: an update

Kasahara, Masanori

doi:10.1016/j.coi.2007.07.009

Cited by 234 publications

(189 citation statements)

References 47 publications

Supporting

Mentioning

177

Contrasting

Unclassified

Order By: Relevance

“…Overall, these findings support the existence of two rounds of WGD in early vertebrates (commonly known as the 2R hypothesis), and one additional WGD in teleost fish, in agreement with other recent findings (for review, see Kasahara 2007). In the lineages that are hypothesized to have experienced WGD, as the synteny group size decreases, the number of chromosomes also decreases, indicating that the majority of the observed duplications in these genomes were generated by a mechanism that retains synteny, such as WGD ( Fig.…”

Section: Groups Of Related Syntenic Segments Support the 2r Hypothesissupporting

confidence: 92%

“…However, analysis of conserved gene order, or synteny, within complete vertebrate genome sequences has provided an increasing body of evidence supporting the 2R hypothesis (McLysaght et al 2002;Panopoulou et al 2003;Vandepoele et al 2004;Dehal and Boore 2005). These studies led Kasahara (2007) to declare that "there is now incontrovertible evidence supporting the 2R hypothesis." Fascination with this hypothesis has endured because of the dramatic consequences such events could have had for the evolution of vertebrates.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Early vertebrate whole genome duplications were predated by a period of intense genome rearrangement

Hufton¹,

Groth²,

Vingron³

et al. 2008

Genome Res.

View full text Add to dashboard Cite

Researchers, supported by data from polyploid plants, have suggested that whole genome duplication (WGD) may induce genomic instability and rearrangement, an idea which could have important implications for vertebrate evolution. Benefiting from the newly released amphioxus genome sequence (Branchiostoma floridae), an invertebrate that researchers have hoped is representative of the ancestral chordate genome, we have used gene proximity conservation to estimate rates of genome rearrangement throughout vertebrates and some of their invertebrate ancestors. We find that, while amphioxus remains the best single source of invertebrate information about the early chordate genome, its genome structure is not particularly well conserved and it cannot be considered a fossilization of the vertebrate preduplication genome. In agreement with previous reports, we identify two WGD events in early vertebrates and another in teleost fish. However, we find that the early vertebrate WGD events were not followed by increased rates of genome rearrangement. Indeed, we measure massive genome rearrangement prior to these WGD events. We propose that the vertebrate WGD events may have been symptoms of a preexisting predisposition toward genomic structural change.

show abstract

Section: Groups Of Related Syntenic Segments Support the 2r Hypothesissupporting

confidence: 92%

mentioning

confidence: 99%

Early vertebrate whole genome duplications were predated by a period of intense genome rearrangement

Hufton¹,

Groth²,

Vingron³

et al. 2008

Genome Res.

View full text Add to dashboard Cite

show abstract

“…A comparison of available sequences from a number of organisms suggests that the two genes arose from the duplication of a common ancestor gene in vertebrates. This may have been as a result of a small duplication or one of the two genome-wide duplications commonly thought to have occurred in vertebrate genomes (2R hypothesis) (Makalowski 2001;Kasahara 2007), before the divergence of the ancestral lamprey and Gnathostomata lineages (Smith et al 2013).…”

Section: Discussionmentioning

confidence: 99%

Gene duplication and neofunctionalization: POLR3G and POLR3GL

et al. 2013

View full text Add to dashboard Cite

RNA polymerase III (Pol III) occurs in two versions, one containing the POLR3G subunit and the other the closely related POLR3GL subunit. It is not clear whether these two Pol III forms have the same function, in particular whether they recognize the same target genes. We show that the POLR3G and POLR3GL genes arose from a DNA-based gene duplication, probably in a common ancestor of vertebrates. POLR3G-as well as POLR3GL-containing Pol III are present in cultured cell lines and in normal mouse liver, although the relative amounts of the two forms vary, with the POLR3G-containing Pol III relatively more abundant in dividing cells. Genome-wide chromatin immunoprecipitations followed by high-throughput sequencing (ChIP-seq) reveal that both forms of Pol III occupy the same target genes, in very constant proportions within one cell line, suggesting that the two forms of Pol III have a similar function with regard to specificity for target genes. In contrast, the POLR3G promoter-not the POLR3GL promoter-binds the transcription factor MYC, as do all other promoters of genes encoding Pol III subunits. Thus, the POLR3G/POLR3GL duplication did not lead to neo-functionalization of the gene product (at least with regard to target gene specificity) but rather to neo-functionalization of the transcription units, which acquired different mechanisms of regulation, thus likely affording greater regulation potential to the cell.

show abstract

“…3C). The duplication generating DrKDM5B and DrKDM5C corresponds to the WGD (3R WGD) that is specific to a fish lineage (Kasahara, 2007).…”

Section: Multiple Gene Duplication Events Identified In Vertebrate Evmentioning

confidence: 99%

Expansion and Functional Divergence of Jumonji C-Containing Histone Demethylases: Significance of Duplications in Ancestral Angiosperms and Vertebrates

et al. 2015

View full text Add to dashboard Cite

The 2R hypothesis: an update

Cited by 234 publications

References 47 publications

Early vertebrate whole genome duplications were predated by a period of intense genome rearrangement

Early vertebrate whole genome duplications were predated by a period of intense genome rearrangement

Gene duplication and neofunctionalization: POLR3G and POLR3GL

Expansion and Functional Divergence of Jumonji C-Containing Histone Demethylases: Significance of Duplications in Ancestral Angiosperms and Vertebrates

Contact Info

Product

Resources

About