scholarly journals The Aquilegia genome reveals a hybrid origin of core eudicots

2018 ◽  
Author(s):  
Gökçe Aköz ◽  
Magnus Nordborg
Keyword(s):  
Evolutionary History ◽  
Genetic Material ◽  
Diploid Species ◽  
Hybrid Origin ◽  
The Core ◽  
Whole Genome Duplications ◽  
Core Eudicots ◽  
Eventual Return ◽  
Genome Duplications ◽  
History Of

AbstractBackgroundWhole-genome duplications (WGD) have dominated the evolutionary history of plants. One consequence of WGD is a dramatic restructuring of the genome as it undergoes diploidization, a process under which deletions and rearrangements of various sizes scramble the genetic material, leading to a repacking of the genome and eventual return to diploidy. Here, we investigate the history of WGD in the columbine genus Aquilegia, a basal eudicot, and use it to illuminate the origins of the core eudicots.ResultsWithin-genome synteny confirms that columbines are ancient tetraploids, and comparison with the grape genome reveals that this tetraploidy appears to be shared with the core eudicots. Thus, the ancient gamma hexaploidy found in all core eudicots must have involved a two-step process: first tetraploidy in the ancestry of all eudicots, then hexaploidy in the ancestry of core eudicots. Furthermore, the precise pattern of synteny sharing suggests that the latter involved allopolyploidization, and that core eudicots thus have a hybrid origin.ConclusionsNovel analyses of synteny sharing together with the well-preserved structure of the columbine genome reveal that the gamma hexaploidy at the root of core eudicots is likely a result of hybridization between a tetraploid and a diploid species.

scholarly journals The Aquilegia genome reveals a hybrid origin of core eudicots

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Gökçe Aköz ◽  
Magnus Nordborg
Keyword(s):  
Evolutionary History ◽  
Genetic Material ◽  
Diploid Species ◽  
Hybrid Origin ◽  
The Core ◽  
Whole Genome Duplications ◽  
Core Eudicots ◽  
Eventual Return ◽  
Genome Duplications ◽  
History Of

Abstract Background Whole-genome duplications (WGDs) have dominated the evolutionary history of plants. One consequence of WGD is a dramatic restructuring of the genome as it undergoes diploidization, a process under which deletions and rearrangements of various sizes scramble the genetic material, leading to a repacking of the genome and eventual return to diploidy. Here, we investigate the history of WGD in the columbine genus Aquilegia, a basal eudicot, and use it to illuminate the origins of the core eudicots. Results Within-genome synteny confirms that columbines are ancient tetraploids, and comparison with the grape genome reveals that this tetraploidy appears to be shared with the core eudicots. Thus, the ancient gamma hexaploidy found in all core eudicots must have involved a two-step process: first, tetraploidy in the ancestry of all eudicots, then hexaploidy in the ancestry of core eudicots. Furthermore, the precise pattern of synteny sharing suggests that the latter involved allopolyploidization and that core eudicots thus have a hybrid origin. Conclusions Novel analyses of synteny sharing together with the well-preserved structure of the columbine genome reveal that the gamma hexaploidy at the root of core eudicots is likely a result of hybridization between a tetraploid and a diploid species.

scholarly journals Evolutionary History and Functional Characterization of the Amphibian Xenosensor CAR

2012 ◽  
Vol 26 (1) ◽  
pp. 14-26 ◽  
Author(s):  
Marianne Mathäs ◽  
Oliver Burk ◽  
Huan Qiu ◽  
Christian Nußhag ◽  
Ute Gödtel-Armbrust ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Functional Characterization ◽  
Constitutive Androstane Receptor ◽  
Pregnane X Receptor ◽  
Constitutive Activity ◽  
Whole Genome Duplications ◽  
Genome Duplications ◽  
History Of ◽  
Land Vertebrates

Abstract The xenosensing constitutive androstane receptor (CAR) is widely considered to have arisen in early mammals via duplication of the pregnane X receptor (PXR). We report that CAR emerged together with PXR and the vitamin D receptor from an ancestral NR1I gene already in early vertebrates, as a result of whole-genome duplications. CAR genes were subsequently lost from the fish lineage, but they are conserved in all taxa of land vertebrates. This contrasts with PXR, which is found in most fish species, whereas it is lost from Sauropsida (reptiles and birds) and plays a role unrelated to xenosensing in Xenopus. This role is fulfilled in Xenopus by CAR, which exhibits low basal activity and pronounced responsiveness to activators such as drugs and steroids, altogether resembling mammalian PXR. The constitutive activity typical for mammalian CAR emerged first in Sauropsida, and it is thus common to all fully terrestrial land vertebrates (Amniota). The constitutive activity can be achieved by humanizing just two amino acids of the Xenopus CAR. Taken together, our results provide a comprehensive reconstruction of the evolutionary history of the NR1I subfamily of nuclear receptors. They identify CAR as the more conserved and remarkably plastic NR1I xenosensor in land vertebrates. Nonmammalian CAR should help to dissect the specific functions of PXR and CAR in the metabolism of xeno- and endobiotics in humans. Xenopus CAR is a first reported amphibian xenosensor, which opens the way to toxicogenomic and bioaugmentation studies in this critically endangered taxon of land vertebrates.

scholarly journals Phylogeny and Multiple Independent Whole-Genome Duplication Events in the Brassicales

2019 ◽  
Author(s):  
Makenzie E. Mabry ◽  
Julia M. Brose ◽  
Paul D. Blischak ◽  
Brittany Sutherland ◽  
Wade T. Dismukes ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Whole Genome ◽  
Genome Survey ◽  
Whole Genome Duplications ◽  
The Family ◽  
Genome Duplications ◽  
Duplication Events ◽  
History Of ◽  
Inference Methods ◽  
Ideal Group

ABSTRACTWhole-genome duplications (WGDs) are prevalent throughout the evolutionary history of plants. For example, dozens of WGDs have been phylogenetically localized across the order Brassicales, specifically, within the family Brassicaceae. However, while its sister family, Cleomaceae, has also been characterized by a WGD, its placement, as well as that of other WGD events in other families in the order, remains unclear. Using phylo-transcriptomics from 74 taxa and genome survey sequencing for 66 of those taxa, we infer nuclear and chloroplast phylogenies to assess relationships among the major families of the Brassicales and within the Brassicaceae. We then use multiple methods of WGD inference to assess placement of WGD events. We not only present well-supported chloroplast and nuclear phylogenies for the Brassicales, but we also putatively place Th-α and provide evidence for previously unknown events, including one shared by at least two members of the Resedaceae, which we name Rs-α. Given its economic importance and many genomic resources, the Brassicales are an ideal group to continue assessing WGD inference methods. We add to the current conversation on WGD inference difficulties, by demonstrating that sampling is especially important for WGD identification.

scholarly journals Evolutionary history of the vertebrate Piwi gene family

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12451
Author(s):  
Javier Gutierrez ◽  
Roy Platt ◽  
Juan C. Opazo ◽  
David A. Ray ◽  
Federico Hoffmann ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Regulatory Proteins ◽  
Vertebrate Evolution ◽  
Transcriptional Gene Silencing ◽  
Whole Genome ◽  
Whole Genome Duplications ◽  
Genome Duplications ◽  
History Of ◽  
Argonaute Family ◽  
The Common

PIWIs are regulatory proteins that belong to the Argonaute family. Piwis are primarily expressed in gonads and protect the germline against the mobilization and propagation of transposable elements (TEs) through transcriptional gene silencing. Vertebrate genomes encode up to four Piwi genes: Piwil1, Piwil2, Piwil3 and Piwil4, but their duplication history is unresolved. We leveraged phylogenetics, synteny and expression analyses to address this void. Our phylogenetic analysis suggests Piwil1 and Piwil2 were retained in all vertebrate members. Piwil4 was the result of Piwil1 duplication in the ancestor of gnathostomes, but was independently lost in ray-finned fishes and birds. Further, Piwil3 was derived from a tandem Piwil1 duplication in the common ancestor of marsupial and placental mammals, but was secondarily lost in Atlantogenata (Xenarthra and Afrotheria) and some rodents. The evolutionary rate of Piwil3 is considerably faster than any Piwi among all lineages, but an explanation is lacking. Our expression analyses suggest Piwi expression has mostly been constrained to gonads throughout vertebrate evolution. Vertebrate evolution is marked by two early rounds of whole genome duplication and many multigene families are linked to these events. However, our analyses suggest Piwi expansion was independent of whole genome duplications.

scholarly journals Vertebrate Alpha2,8-Sialyltransferases (ST8Sia): A Teleost Perspective

2020 ◽  
Vol 21 (2) ◽  
pp. 513 ◽  
Author(s):  
Marzia Tindara Venuto ◽  
Mathieu Decloquement ◽  
Joan Martorell Ribera ◽  
Maxence Noel ◽  
Alexander Rebl ◽  
...  
Keyword(s):  
Fish Species ◽  
Evolutionary History ◽  
Recombinant Enzymes ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Multiple Sequence Alignments ◽  
Functional Studies ◽  
Genome Duplications ◽  
History Of ◽  
Species Specific

We identified and analyzed α2,8-sialyltransferases sequences among 71 ray-finned fish species to provide the first comprehensive view of the Teleost ST8Sia repertoire. This repertoire expanded over the course of Vertebrate evolution and was primarily shaped by the whole genome events R1 and R2, but not by the Teleost-specific R3. We showed that duplicated st8sia genes like st8sia7, st8sia8, and st8sia9 have disappeared from Tetrapods, whereas their orthologues were maintained in Teleosts. Furthermore, several fish species specific genome duplications account for the presence of multiple poly-α2,8-sialyltransferases in the Salmonidae (ST8Sia II-r1 and ST8Sia II-r2) and in Cyprinus carpio (ST8Sia IV-r1 and ST8Sia IV-r2). Paralogy and synteny analyses provided more relevant and solid information that enabled us to reconstruct the evolutionary history of st8sia genes in fish genomes. Our data also indicated that, while the mammalian ST8Sia family is comprised of six subfamilies forming di-, oligo-, or polymers of α2,8-linked sialic acids, the fish ST8Sia family, amounting to a total of 10 genes in fish, appears to be much more diverse and shows a patchy distribution among fish species. A focus on Salmonidae showed that (i) the two copies of st8sia2 genes have overall contrasted tissue-specific expressions, with noticeable changes when compared with human co-orthologue, and that (ii) st8sia4 is weakly expressed. Multiple sequence alignments enabled us to detect changes in the conserved polysialyltransferase domain (PSTD) of the fish sequences that could account for variable enzymatic activities. These data provide the bases for further functional studies using recombinant enzymes.

Evolutionary history of Purple cone spruce (Picea purpurea) in the Qinghai-Tibet Plateau: homoploid hybrid origin and Pleistocene expansion

2013 ◽  
Vol 23 (2) ◽  
pp. 343-359 ◽  
Author(s):  
Yongshuai Sun ◽  
Richard J. Abbott ◽  
Lili Li ◽  
Long Li ◽  
Jiabin Zou ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Hybrid Origin ◽  
Tibet Plateau ◽  
History Of ◽  
Homoploid Hybrid ◽  
Qinghai Tibet Plateau

scholarly journals Insights on the process of reciprocal gene loss in the duplicate DPL genes of rice

2019 ◽  
Author(s):  
Xun Xu ◽  
Song Ge ◽  
Fu-min Zhang
Keyword(s):  
Evolutionary History ◽  
Gene Loss ◽  
Diploid Species ◽  
Recent Common Ancestor ◽  
Duplicate Genes ◽  
Evolutionary Divergence ◽  
Dna Transposons ◽  
B Genome ◽  
A Genome ◽  
History Of

Abstract Background: Reciprocal gene loss (RGL) of duplicate genes is an important genetic resource of reproductive isolation, which is essential for speciation. In the past decades, various RGL patterns have been revealed, but RGL process is still poorly understood. The RGL of the duplicate DOPPELGANGER1 (DPL1) and DOPPELGANGER2 (DPL2) gene can lead to BDM-type hybrid incompatibility between two rice subspecies. The evolutionary history of the duplicate genes, including their origin and mechanism of duplication as well as their evolutionary divergence after the duplication, remains unclear. In this study, we investigated the evolutionary history of the duplicate genes for gaining insights into the process of RGL.Results: We reconstructed phylogenetic relationships of DPL copies from all 15 diploid species representing six genome types of rice genus and then found that all the DPL copies from the latest diverged A- and B-genome gather into one monophyletic clade. Southern blot analysis also detected definitely two DPL copies only in A- and B-genome. High conserved collinearity can be observed between A- and B-genomic segments containing DPL1 and DPL2 respectively but not between DPL1 and DPL2 segments. Investigations of transposon elements indicated that DPL duplication is related to DNA transposons. Likelihood-based analyses with branch models showed a relaxation of selective constraint in DPL1 lineage but an enhancement in DPL2 lineage after DPL duplication. Sequence analysis also indicated that quite a few defective DPL1 can be found in 6 wild and cultivated species out of all 8 species of A-genome but only one defective DPL2 occurs in a cultivated rice subspecies. Conclusions: DPL duplication of rice originated in the recent common ancestor of A- and B-genome about 6.76 million years ago and the duplication was possibly caused by DNA transposons. The DPL1 is a redundant copy and has being in the process of pseudogenization, suggesting that artificial selection may play an important role in forming the RGL of DPLs between two rice subspecies during the domestication.

scholarly journals New insights into homoeologous copy number variations in the hexaploid wheat genome

2020 ◽  
Author(s):  
Caroline Juery ◽  
Lorenzo Concia ◽  
Romain De Oliveira ◽  
Nathan Papon ◽  
Ricardo Ramírez-González ◽  
...  
Keyword(s):  
Hexaploid Wheat ◽  
Core Genome ◽  
Diploid Species ◽  
Housekeeping Genes ◽  
Copy Number Variations ◽  
List Type ◽  
The Core ◽  
History Of ◽  
Function Expression ◽  
Dispensable Genome

AbstractBread wheat is an allohexaploid species originating from two successive and recent rounds of hybridization between three diploid species that were very similar in terms of chromosome number, genome size, TE content, gene content and synteny. As a result, it has long been considered that most of the genes were in three pairs of homoeologous copies. However, these so-called triads represent only one half of wheat genes, while the remaining half belong to homoeologous groups with various number of copies across subgenomes. In this study, we examined and compared the distribution, conservation, function, expression and epigenetic profiles of triads with homoeologous groups having undergone a deletion (dyads) or a duplication (tetrads) in one subgenome. We show that dyads and tetrads are mostly located in distal regions and have lower expression level and breadth than triads. Moreover, they are enriched in functions related to adaptation and more associated with the repressive H3K27me3 modification. Altogether, these results suggest that triads mainly correspond to housekeeping genes and are part of the core genome, while dyads and tetrads belong to the Triticeae dispensable genome. In addition, by comparing the different categories of dyads and tetrads, we hypothesize that, unlike most of the allopolyploid species, subgenome dominance and biased fractionation are absent in hexaploid wheat. Differences observed between the three subgenomes are more likely related to two successive and ongoing waves of post-polyploid diploidization, that had impacted A and B more significantly than D, as a result of the evolutionary history of hexaploid wheat.Core ideasOnly one half of hexaploid wheat genes are in triads, i.e. in a 1:1:1 ratio across subgenomesTriads are likely part of the core genome; dyads and tetrads belong to the dispensable genomeSubgenome dominance and biased fractionation are absent in hexaploid wheatSubgenome differences are related to two successive waves of post-polyploid diploidization

Expanding the RNA Virosphere by Unbiased Metagenomics

2019 ◽  
Vol 6 (1) ◽  
pp. 119-139 ◽  
Author(s):  
Yong-Zhen Zhang ◽  
Yan-Mei Chen ◽  
Wen Wang ◽  
Xin-Chen Qin ◽  
Edward C. Holmes
Keyword(s):  
Evolutionary History ◽  
Genetic Material ◽  
Virus Species ◽  
Future Directions ◽  
Important Species ◽  
Virus Diversity ◽  
Limited Perspective ◽  
Etiologic Agents ◽  
History Of ◽  
Overt Disease

Although viruses comprise the most abundant genetic material in the biosphere, to date only several thousand virus species have been formally defined. Such a limited perspective on virus diversity has in part arisen because viruses were traditionally considered only as etiologic agents of overt disease in humans or economically important species and were often difficult to identify using cell culture. This view has dramatically changed with the rise of metagenomics, which is transforming virus discovery and revealing a remarkable diversity of viruses sampled from diverse cellular organisms. These newly discovered viruses help fill major gaps in the evolutionary history of viruses, revealing a near continuum of diversity among genera, families, and even orders of RNA viruses. Herein, we review some of the recent advances in our understanding of the RNA virosphere that have stemmed from metagenomics, note future directions, and highlight some of the remaining challenges to this rapidly developing field.

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