When we included the highly divergent CG30461 in the phylogenetic analysis, it formed a separate, well-supported clade that is part of the clade containing the paralogs of CG9000, showing that it, too, likely originated via duplication in a common ancestor.
Four paralogs of RAD23 are present in Arabidopsis which appear to be originated in different duplication events.
The S. cerevisiae VBA3 and VBA5 genes are paralogs originated in a duplication event occurring after S. mikatae speciation.
There is about 85 90% homology between the tandem repeat domains and the regions flanking the repeats of hrp II and hrp III genes which imply that both have originated in the duplication of an ancestral sequence [ 49].
As for the position of acanthopterygian pax6b genes questioned by Ravi et al. (fig. 2 A), our phylogenetic analysis (fig. 2 B) supported the scenario that they originated in a duplication in the teleost fish lineage (Hypothesis 2) instead of the scenario that it originated in the 2R-WGD (Hypothesis 1).
In contrast to vertebrates, the basally diverging cephalochordate amphioxus possesses a single Pax2/5/8 gene that is equally related to Pax2, Pax5 and Pax8 [ 52], and urochordates have two Pax2/5/8 genes (Pax2/5/8a and Pax2/5/8b) [ 38, 53, 54] that originated in a duplication event prior to the divergence of larvacean and ascidian lineages [ 38].
In this study of duplications and deletions in adapting C. elegans populations following an experimental phase of fitness decline, the size range of duplications originating in the adaptive recovery phase with population expansion was 1.6 661 kb with a median duplication span of 191.5 kb.
Whereas all archaeal and eukaryal organisms harbor only one gene encoding glycerate kinase, paralogous genes that originated in gene duplications and/or horizontal gene transfer (HGT) were found in several bacteria (e.g. Ralstonia solanacearum, Sinorhizobium meliloti (Fig. 7)).
It is evident that two copies of genes encoding ZEP proteins are generally encoded in photosynthetic eukaryotes, which represent out-paralogues originating in an ancient single gene duplication event.
Instead, GbE originated via duplication of a proto- Mb gene in the stem lineage of gnathostomes.
The same number of duplications has been reported for the rice genome, in which 23 Os Hsp20 genes were originated via duplication events [ 30].
