scholarly journals Diverse genome organization following 13 independent mesopolyploid events in Brassicaceae contrasts with convergent patterns of gene retention

2017 ◽  
Author(s):  
Terezie Mandáková ◽  
Zheng Li ◽  
Michael S. Barker ◽  
Martin A. Lysak

SummaryHybridization and polyploidy followed by genome-wide diploidization significantly impacted the diversification of land plants. The ancient At-α whole-genome duplication (WGD) preceded the diversification of crucifers (Brassicaceae). Some genera and tribes also experienced younger, mesopolyploid WGDs concealed by subsequent genome diploidization. Here we tested if multiple base chromosome numbers originated due to genome diploidization after independent mesopolyploid WGDs and how diploidization impacted post-polyploid gene retention. Sixteen species representing ten Brassicaceae tribes were analyzed by comparative chromosome painting and/or whole-transcriptome analysis of gene age distributions and phylogenetic analyses of gene duplications. Overall, we found evidence for at least 13 independent mesopolyploidies followed by different degrees of diploidization across the Brassicaceae. New mesotetraploid events were uncovered for tribes Anastaticeae, Iberideae and Schizopetaleae, and mesohexaploid WGDs for Cochlearieae and Physarieae. In contrast, we found convergent patterns of gene retention and loss among these independent WGDs. Our combined analyses of Brassicaceae genomic data indicate that the extant chromosome number variation in many plant groups, and especially polybasic but monophyletic taxa, can result from clade-specific genome duplications followed by diploidization. Our observation of parallel gene retention and loss across multiple independent WGDs provides one of the first multi-species tests that post-polyploid genome evolution is predictable.Significance statementOur data show that multiple base chromosome numbers in some Brassicaceae clades originated due to genome diploidization following multiple independent whole-genome duplications (WGD). The parallel gene retention/loss across independent WGDs and diploidizations provides one of the first tests that post-polyploid genome evolution is predictable.

Author(s):  
Federico G Hoffmann ◽  
Jay F Storz ◽  
Shigehiro Kuraku ◽  
Michael W Vandewege ◽  
Juan C Opazo

Abstract Globin-X (GbX) is an enigmatic member of the vertebrate globin gene family with a wide phyletic distribution that spans protostomes and deuterostomes. Unlike canonical globins such as hemoglobins and myoglobins, functional data suggest that GbX does not have a primary respiratory function. Instead, evidence suggests that the monomeric, membrane-bound GbX may play a role in cellular signaling or protection against the oxidation of membrane lipids. Recently released genomes from key vertebrates provide an excellent opportunity to address questions about the early stages of the evolution of GbX in vertebrates. We integrate bioinformatics, synteny, and phylogenetic analyses to characterize the diversity of GbX genes in non-teleost ray-finned fishes, resolve relationships between the GbX genes of cartilaginous fish and bony vertebrates, and demonstrate that the GbX genes of cyclostomes and gnathostomes derive from independent duplications. Our study highlights the role that whole-genome duplications (WGDs) have played in expanding the repertoire of genes in vertebrate genomes. Our results indicate that GbX paralogs have a remarkably high rate of retention following WGDs relative to other globin genes, and provide an evolutionary framework for interpreting results of experiments that examine functional properties of GbX and patterns of tissue-specific expression. By identifying GbX paralogs that are products of different WGDs, our results can guide the design of experimental work to explore whether gene duplicates that originate via WGDs have evolved novel functional properties or expression profiles relative to singleton or tandemly duplicated copies of GbX.


Author(s):  
Xinyi Guo ◽  
Terezie Mandáková ◽  
Karolína Trachtová ◽  
Barış Özüdoğru ◽  
Jianquan Liu ◽  
...  

Abstract Pervasive hybridization and whole genome duplications (WGDs) influenced genome evolution in several eukaryotic lineages. While frequent and recurrent hybridizations may result in reticulate phylogenies, the evolutionary events underlying these reticulations, including detailed structure of the ancestral diploid and polyploid genomes, were only rarely reconstructed. Here, we elucidate the complex genomic history of a monophyletic clade from the mustard family (Brassicaceae), showing contentious relationships to the early-diverging clades of this model plant family. Genome evolution in the crucifer tribe Biscutelleae (c. 60 species, 5 genera) was dominated by pervasive hybridizations and subsequent genome duplications. Diversification of an ancestral diploid genome into several divergent but crossable genomes was followed by hybridizations between these genomes. Whereas a single genus (Megadenia) remained diploid, the four remaining genera originated by allopolyploidy (Biscutella, Lunaria, Ricotia) or autopolyploidy (Heldreichia). The contentious relationships among the Biscutelleae genera, and between the tribe and other early diverged crucifer lineages, are best explained by close genomic relatedness among the recurrently hybridizing ancestral genomes. By using complementary cytogenomics and phylogenomics approaches, we demonstrate that the origin of a monophyletic plant clade can be more complex than a parsimonious assumption of a single WGD spurring post-polyploid cladogenesis. Instead, recurrent hybridization among the same and/or closely related parental genomes may phylogenetically interlink diploid and polyploid genomes despite the incidence of multiple independent WGDs. Our results provide new insights into evolution of early-diverging Brassicaceae lineages and elucidate challenges in resolving the contentious relationships within and between land plant lineages with pervasive hybridization and WGDs.


2020 ◽  
Author(s):  
Thomas Naake ◽  
Hiroshi A. Maeda ◽  
Sebastian Proost ◽  
Takayuki Tohge ◽  
Alisdair R. Fernie

AbstractThe emergence of type III polyketide synthases (PKSs) was a pre-requisite for the conquest of land by the green lineage. To study the deep evolutionary history of this key family, we used phylogenomic synteny network and phylogenetic analyses of whole-genome data from 126 species spanning the green lineage. This study thereby combined study of genomic location and context with changes in gene sequences. We found that two major clades, CHS and LAP5/6 homologs, evolved early by a segmental duplication event prior to the divergence of Bryophytes and Tracheophytes. We propose that the macroevolution of the type III PKS superfamily is governed by whole-genome duplications and triplications. Intriguingly, the combined phylogenetic and synteny analyses in this study shed new insights into changes in the genomic location and context that are retained for a longer time scale with more recent functional divergence captured by gene sequence alterations.


2021 ◽  
Author(s):  
Federico Hoffmann ◽  
Jay Storz ◽  
Shigehiro Kuraku ◽  
Michael Vandewege ◽  
Juan C. Opazo

The globin superfamily of vertebrate genes is a textbook example of how the interplay between local gene duplications, whole-genome duplications, and regulatory changes can facilitate the evolution of novel protein functions. Almost every vertebrate examined possesses copies of hemoglobin and myoglobin in their genomes, and both cytoglobin and neuroglobin are present in the vast majority of vertebrate genomes surveyed as well. The phylogenetic distribution of globin-E, globin-Y and globin-X (GbX), however, is more spotty, suggesting multiple independent gene losses. Globin-X is an enigmatic globin with a wide phyletic distribution that spans protostomes and deuterostomes. Unlike canonical globins such as hemoglobins and myoglobins, functional data suggest that GbX does not have a primary respiratory function. Instead, available evidence suggests that GbX may play a role in protecting cells from oxidative damage and in reducing nitrite and it is predicted to be bound to the cell membrane. Recently released genomes from key vertebrate taxa provide an excellent opportunity to address questions about the early stages of evolution of these genes in vertebrates. In the current study, we integrate bioinformatic, synteny and phylogenetic analyses to characterize the diversity of GbX genes in non-teleost ray-finned fishes, resolve relationships between the GbX genes of cartilaginous fish and the GbX genes of bony vertebrates, and demonstrate that the GbX genes of cyclostomes and gnathostomes have independent duplicative histories. Our study highlights the role that whole genome duplications (WGDs) have played in expanding the repertoire of genes in vertebrate genomes. Our results indicate that GbX paralogs have a remarkably high rate of retention following WGDs in comparison to other globin genes, and also provide an evolutionary framework for interpreting results of experiments that examine functional properties of GbX and patterns of tissue-specific expression. By identifying GbX genes products of different WGDs in the vertebrate tree of life, our results can guide the design of experimental work to explore whether gene duplicates that originate via WGDs have evolved novel functional properties or expression profiles relative to singleton or tandemly duplicated copies of GbX.


2019 ◽  
Author(s):  
Amanda Coward Black ◽  
Mary Clay Bailey ◽  
Marisa Ruane-Foster ◽  
Juan C. Opazo ◽  
Federico G. Hoffmann

ABSTRACTThe Rapidly Accelerated Fibrosarcoma (RAF) kinases are part of large group of serine/threonine-specific protein kinases that play important roles in cell differentiation and organism development. Animal RAF kinases are key connectors in the signaling cascade that links the small G protein RAS and the Mitogen-activated protein kinase phosphorylation pathway. Mutations in the RAF genes have been linked to a number of cancers including melanoma, lung cancer, colorectal cancer, thyroid cancer, and ovarian cancer. Most animals possess a single RAF gene, but vertebrates have three RAF genes in their genomes, named as A-, B-, and C-RAF, the latter also known as RAF-1. The emergence of the multiple copies of vertebrate RAFs is not well resolved, on the one hand, because of sequence and functional similarities, some authors speculate that vertebrate B-Raf is most closely related to the RAF genes of the fruit fly and Caenorhabditis elegans, whereas a competing hypothesis is that the A-, B- and C-RAF paralogs emerged from the two rounds of whole genome duplications that occurred early in the evolution of vertebrates. We applied a comparative approach grounded in synteny and phylogenetic analyses to evaluate these two scenarios. Our results are consistent with the hypothesis that the RAF genes of vertebrates are paralogs generated by whole genome duplications. Thus, the functional similarities between vertebrate B-RAF and invertebrate RAF probably reflect the retention of ancestral characters. Interestingly, data from the literature indicate that B-RAF is the paralog that associated with cancer more strongly, and also yields the most severe phenotypes when knocked out.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1017
Author(s):  
Hirohisa Mekata ◽  
Tomohiro Okagawa ◽  
Satoru Konnai ◽  
Takayuki Miyazawa

Bovine foamy virus (BFV) is a member of the foamy virus family in cattle. Information on the epidemiology, transmission routes, and whole-genome sequences of BFV is still limited. To understand the characteristics of BFV, this study included a molecular survey in Japan and the determination of the whole-genome sequences of 30 BFV isolates. A total of 30 (3.4%, 30/884) cattle were infected with BFV according to PCR analysis. Cattle less than 48 months old were scarcely infected with this virus, and older animals had a significantly higher rate of infection. To reveal the possibility of vertical transmission, we additionally surveyed 77 pairs of dams and 3-month-old calves in a farm already confirmed to have BFV. We confirmed that one of the calves born from a dam with BFV was infected. Phylogenetic analyses revealed that a novel genotype was spread in Japan. In conclusion, the prevalence of BFV in Japan is relatively low and three genotypes, including a novel genotype, are spread in Japan.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gareth B. Gillard ◽  
Lars Grønvold ◽  
Line L. Røsæg ◽  
Matilde Mengkrog Holen ◽  
Øystein Monsen ◽  
...  

Abstract Background Whole genome duplication (WGD) events have played a major role in eukaryotic genome evolution, but the consequence of these extreme events in adaptive genome evolution is still not well understood. To address this knowledge gap, we used a comparative phylogenetic model and transcriptomic data from seven species to infer selection on gene expression in duplicated genes (ohnologs) following the salmonid WGD 80–100 million years ago. Results We find rare cases of tissue-specific expression evolution but pervasive expression evolution affecting many tissues, reflecting strong selection on maintenance of genome stability following genome doubling. Ohnolog expression levels have evolved mostly asymmetrically, by diverting one ohnolog copy down a path towards lower expression and possible pseudogenization. Loss of expression in one ohnolog is significantly associated with transposable element insertions in promoters and likely driven by selection on gene dosage including selection on stoichiometric balance. We also find symmetric expression shifts, and these are associated with genes under strong evolutionary constraints such as ribosome subunit genes. This possibly reflects selection operating to achieve a gene dose reduction while avoiding accumulation of “toxic mutations”. Mechanistically, ohnolog regulatory divergence is dictated by the number of bound transcription factors in promoters, with transposable elements being one likely source of novel binding sites driving tissue-specific gains in expression. Conclusions Our results imply pervasive adaptive expression evolution following WGD to overcome the immediate challenges posed by genome doubling and to exploit the long-term genetic opportunities for novel phenotype evolution.


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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shingo Nishiki ◽  
Kenichi Lee ◽  
Mizue Kanai ◽  
Shu-ichi Nakayama ◽  
Makoto Ohnishi

AbstractJapan has had a substantial increase in syphilis cases since 2013. However, research on the genomic features of the Treponema pallidum subspecies pallidum (TPA) strains from these cases has been limited. Here, we elucidated the genetic variations and relationships between TPA strains in Japan (detected between 2014 and 2018) and other countries by whole-genome sequencing and phylogenetic analyses, including syphilis epidemiological surveillance data and information on patient sexual orientation. Seventeen of the 20 strains in Japan were SS14- and the remaining 3 were Nichols-lineage. Sixteen of the 17 SS14-lineage strains were classified into previously reported Sub-lineage 1B. Sub-lineage 1B strains in Japan have formed distinct sub-clusters of strains from heterosexuals and strains from men who have sex with men. These strains were closely related to reported TPA strains in China, forming an East-Asian cluster. However, those strains in these countries evolved independently after diverging from their most recent common ancestor and expanded their genetic diversity during the time of syphilis outbreak in each country. The genetic difference between the TPA strains in these countries was characterized by single-nucleotide-polymorphism analyses of their penicillin binding protein genes. Taken together, our results elucidated the detailed phylogenetic features and transmission networks of syphilis.


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