scholarly journals Widespread ancient whole genome duplications in Malpighiales coincide with Eocene global climatic upheaval

2017 ◽  
Author(s):  
Liming Cai ◽  
Zhenxiang Xi ◽  
André M. Amorim ◽  
M. Sugumaran ◽  
Joshua S. Rest ◽  
...  
Keyword(s):  
Large Scale ◽  
Vascular Plant ◽  
Strong Support ◽  
Flowering Plant ◽  
Whole Genome ◽  
Negative Consequences ◽  
Whole Genome Duplications ◽  
Genome Duplications ◽  
Genomic Studies ◽  
The Tropics

AbstractAncient whole genome duplications (WGDs) are important in eukaryotic genome evolution, and are especially prominent in plants. Recent genomic studies from large vascular plant clades, including ferns, gymnosperms, and angiosperms suggest that WGDs may represent a crucial mode of speciation. Moreover, numerous WGDs have been dated to events coinciding with major episodes of global and climatic upheaval, including the mass extinction at the KT boundary (~65 Ma) and during more recent intervals of global aridification in the Miocene (~10-5 Ma). These findings have led to the hypothesis that polyploidization may buffer lineages against the negative consequences of such disruptions. Here, we explore WGDs in the large, and diverse flowering plant clade Malpighiales using a combination of transcriptomes and complete genomes from 42 species. We conservatively identify 22 ancient WGDs, widely distributed across Malpighiales subclades. Our results provide strong support for the hypothesis that WGD is an important mode of speciation in plants. Importantly, we also identify that these events are clustered around the Eocene-Paleocene Transition (~54 Ma), during which time the planet was warmer and wetter than any period in the Cenozoic. These results establish that the Eocene Climate Optimum represents another, previously unrecognized, period of prolific WGDs in plants, and lends support to the hypothesis that polyploidization promotes adaptation and enhances plant survival during major episodes of global change. Malpighiales, in particular, may have been particularly influenced by these events given their predominance in the tropics where Eocene warming likely had profound impacts owing to the relatively tight thermal tolerances of tropical organisms.Significance StatementWhole genome duplications (WGDs) are hypothesized to generate adaptive variations during episodes of climate change and global upheaval. Using large-scale phylogenomic assessments, we identify an impressive 22 ancient WGDs in the large, tropical flowering plant clade Malpighiales. This supports growing evidence that ancient WGDs are far more common than has been thought. Additionally, we identify that WGDs are clustered during a narrow window of time, ~54 Ma, when the climate was warmer and more humid than during any period in the last ~65 Ma. This lends support to the hypothesis that WGDs are associated with surviving climatic upheavals, especially for tropical organisms like Malpighiales, which have tight thermal tolerances.

scholarly journals Tangled up in two: a burst of genome duplications at the end of the Cretaceous and the consequences for plant evolution

2014 ◽  
Vol 369 (1648) ◽  
pp. 20130353 ◽  
Author(s):  
Kevin Vanneste ◽  
Steven Maere ◽  
Yves Van de Peer
Keyword(s):  
Large Scale ◽  
Plant Evolution ◽  
Small Scale ◽  
Whole Genome ◽  
Polyploid Species ◽  
Plant Genomes ◽  
Whole Genome Duplications ◽  
Genome Duplications ◽  
Duplication Events ◽  
Biological Innovations

Genome sequencing has demonstrated that besides frequent small-scale duplications, large-scale duplication events such as whole genome duplications (WGDs) are found on many branches of the evolutionary tree of life. Especially in the plant lineage, there is evidence for recurrent WGDs, and the ancestor of all angiosperms was in fact most likely a polyploid species. The number of WGDs found in sequenced plant genomes allows us to investigate questions about the roles of WGDs that were hitherto impossible to address. An intriguing observation is that many plant WGDs seem associated with periods of increased environmental stress and/or fluctuations, a trend that is evident for both present-day polyploids and palaeopolyploids formed around the Cretaceous–Palaeogene (K–Pg) extinction at 66 Ma. Here, we revisit the WGDs in plants that mark the K–Pg boundary, and discuss some specific examples of biological innovations and/or diversifications that may be linked to these WGDs. We review evidence for the processes that could have contributed to increased polyploid establishment at the K–Pg boundary, and discuss the implications on subsequent plant evolution in the Cenozoic.

scholarly journals The Rhododendron Genome and Chromosomal Organization Provide Insight into Shared Whole-Genome Duplications across the Heath Family (Ericaceae)

2019 ◽  
Vol 11 (12) ◽  
pp. 3353-3371 ◽  
Author(s):  
Valerie L Soza ◽  
Dale Lindsley ◽  
Adam Waalkes ◽  
Elizabeth Ramage ◽  
Rupali P Patwardhan ◽  
...  
Keyword(s):  
Genome Annotation ◽  
Large Scale ◽  
De Novo ◽  
Gene Annotation ◽  
Whole Genome ◽  
Genomic Libraries ◽  
Gene Pairs ◽  
Whole Genome Duplications ◽  
Genome Duplications ◽  
Large Genus

Abstract The genus Rhododendron (Ericaceae), which includes horticulturally important plants such as azaleas, is a highly diverse and widely distributed genus of >1,000 species. Here, we report the chromosome-scale de novo assembly and genome annotation of Rhododendron williamsianum as a basis for continued study of this large genus. We created multiple short fragment genomic libraries, which were assembled using ALLPATHS-LG. This was followed by contiguity preserving transposase sequencing (CPT-seq) and fragScaff scaffolding of a large fragment library, which improved the assembly by decreasing the number of scaffolds and increasing scaffold length. Chromosome-scale scaffolding was performed by proximity-guided assembly (LACHESIS) using chromatin conformation capture (Hi-C) data. Chromosome-scale scaffolding was further refined and linkage groups defined by restriction-site associated DNA (RAD) sequencing of the parents and progeny of a genetic cross. The resulting linkage map confirmed the LACHESIS clustering and ordering of scaffolds onto chromosomes and rectified large-scale inversions. Assessments of the R. williamsianum genome assembly and gene annotation estimate them to be 89% and 79% complete, respectively. Predicted coding sequences from genome annotation were used in syntenic analyses and for generating age distributions of synonymous substitutions/site between paralgous gene pairs, which identified whole-genome duplications (WGDs) in R. williamsianum. We then analyzed other publicly available Ericaceae genomes for shared WGDs. Based on our spatial and temporal analyses of paralogous gene pairs, we find evidence for two shared, ancient WGDs in Rhododendron and Vaccinium (cranberry/blueberry) members that predate the Ericaceae family and, in one case, the Ericales order.

scholarly journals Hybrid origins and the earliest stages of diploidization in the highly successful recent polyploid Capsella bursa-pastoris

2015 ◽  
Vol 112 (9) ◽  
pp. 2806-2811 ◽  
Author(s):  
Gavin M. Douglas ◽  
Gesseca Gos ◽  
Kim A. Steige ◽  
Adriana Salcedo ◽  
Karl Holm ◽  
...  
Keyword(s):  
Positive Selection ◽  
Large Scale ◽  
Gene Loss ◽  
Strong Support ◽  
Purifying Selection ◽  
Plant Evolution ◽  
Flowering Plant ◽  
Whole Genome ◽  
Widespread Species ◽  
Genome Wide

Whole-genome duplication (WGD) events have occurred repeatedly during flowering plant evolution, and there is growing evidence for predictable patterns of gene retention and loss following polyploidization. Despite these important insights, the rate and processes governing the earliest stages of diploidization remain poorly understood, and the relative importance of genetic drift, positive selection, and relaxed purifying selection in the process of gene degeneration and loss is unclear. Here, we conduct whole-genome resequencing in Capsella bursa-pastoris, a recently formed tetraploid with one of the most widespread species distributions of any angiosperm. Whole-genome data provide strong support for recent hybrid origins of the tetraploid species within the past 100,000–300,000 y from two diploid progenitors in the Capsella genus. Major-effect inactivating mutations are frequent, but many were inherited from the parental species and show no evidence of being fixed by positive selection. Despite a lack of large-scale gene loss, we observe a decrease in the efficacy of natural selection genome-wide due to the combined effects of demography, selfing, and genome redundancy from WGD. Our results suggest that the earliest stages of diploidization are associated with quantitative genome-wide decreases in the strength and efficacy of selection rather than rapid gene loss, and that nonfunctionalization can receive a “head start” through a legacy of deleterious variants and differential expression originating in parental diploid populations.

scholarly journals Chromosome Distribution of Highly Conserved Tandemly Arranged Repetitive DNAs in the Siberian Sturgeon (Acipenser baerii)

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1375
Author(s):  
Larisa S. Biltueva ◽  
Dmitry Yu. Prokopov ◽  
Svetlana A. Romanenko ◽  
Elena A. Interesova ◽  
Manfred Schartl ◽  
...  
Keyword(s):  
Duplication Event ◽  
Siberian Sturgeon ◽  
Genome Duplication Event ◽  
Acipenser Baerii ◽  
Whole Genome Duplications ◽  
Sturgeon Species ◽  
Genome Duplications ◽  
Size Groups ◽  
Genomic Studies ◽  
Syntenic Regions

Polyploid genomes present a challenge for cytogenetic and genomic studies, due to the high number of similar size chromosomes and the simultaneous presence of hardly distinguishable paralogous elements. The karyotype of the Siberian sturgeon (Acipenser baerii) contains around 250 chromosomes and is remarkable for the presence of paralogs from two rounds of whole-genome duplications (WGD). In this study, we applied the sterlet-derived acipenserid satDNA-based whole chromosome-specific probes to analyze the Siberian sturgeon karyotype. We demonstrate that the last genome duplication event in the Siberian sturgeon was accompanied by the simultaneous expansion of several repetitive DNA families. Some of the repetitive probes serve as good cytogenetic markers distinguishing paralogous chromosomes and detecting ancestral syntenic regions, which underwent fusions and fissions. The tendency of minisatellite specificity for chromosome size groups previously observed in the sterlet genome is also visible in the Siberian sturgeon. We provide an initial physical chromosome map of the Siberian sturgeon genome supported by molecular markers. The application of these data will facilitate genomic studies in other recent polyploid sturgeon species.

scholarly journals On the Expansion of “Dangerous” Gene Repertoires by Whole-Genome Duplications in Early Vertebrates

Cell Reports ◽  
2012 ◽  
Vol 2 (5) ◽  
pp. 1387-1398 ◽  
Author(s):  
Param Priya Singh ◽  
Séverine Affeldt ◽  
Ilaria Cascone ◽  
Rasim Selimoglu ◽  
Jacques Camonis ◽  
...  
Keyword(s):  
Whole Genome ◽  
Whole Genome Duplications ◽  
Genome Duplications ◽  
Early Vertebrates

scholarly journals Legume Cytosolic and Plastid Acetyl-Coenzyme—A Carboxylase Genes Differ by Evolutionary Patterns and Selection Pressure Schemes Acting before and after Whole-Genome Duplications

Genes ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 563 ◽  
Author(s):  
Anna Szczepaniak ◽  
Michał Książkiewicz ◽  
Jan Podkowiński ◽  
Katarzyna Czyż ◽  
Marek Figlerowicz ◽  
...  
Keyword(s):  
Selection Pressure ◽  
Coenzyme A ◽  
Phylogenetic Inference ◽  
Whole Genome ◽  
Evolutionary Patterns ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Whole Genome Duplications ◽  
Genome Duplications ◽  
Acetyl Coenzyme A Carboxylase

Acetyl-coenzyme A carboxylase (ACCase, E.C.6.4.1.2) catalyzes acetyl-coenzyme A carboxylation to malonyl coenzyme A. Plants possess two distinct ACCases differing by cellular compartment and function. Plastid ACCase contributes to de novo fatty acid synthesis, whereas cytosolic enzyme to the synthesis of very long chain fatty acids, phytoalexins, flavonoids, and anthocyanins. The narrow leafed lupin (Lupinus angustifolius L.) represents legumes, a plant family which evolved by whole-genome duplications (WGDs). The study aimed on the contribution of these WGDs to the multiplication of ACCase genes and their further evolutionary patterns. The molecular approach involved bacterial artificial chromosome (BAC) library screening, fluorescent in situ hybridization, linkage mapping, and BAC sequencing. In silico analysis encompassed sequence annotation, comparative mapping, selection pressure calculation, phylogenetic inference, and gene expression profiling. Among sequenced legumes, the highest number of ACCase genes was identified in lupin and soybean. The most abundant plastid ACCase subunit genes were accB. ACCase genes in legumes evolved by WGDs, evidenced by shared synteny and Bayesian phylogenetic inference. Transcriptional activity of almost all copies was confirmed. Gene duplicates were conserved by strong purifying selection, however, positive selection occurred in Arachis (accB2) and Lupinus (accC) lineages, putatively predating the WGD event(s). Early duplicated accA and accB genes underwent transcriptional sub-functionalization.

scholarly journals Widespread ancient whole-genome duplications in Malpighiales coincide with Eocene global climatic upheaval

2018 ◽  
Vol 221 (1) ◽  
pp. 565-576 ◽  
Author(s):  
Liming Cai ◽  
Zhenxiang Xi ◽  
André M. Amorim ◽  
M. Sugumaran ◽  
Joshua S. Rest ◽  
...  
Keyword(s):  
Whole Genome ◽  
Whole Genome Duplications ◽  
Genome Duplications
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