scholarly journals Evolutionary research on the expansin protein family during the plant transition to land provides new insights into the development of Tartary buckwheat fruit

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wenjun Sun ◽  
Haomiao Yu ◽  
Moyang Liu ◽  
Zhaotang Ma ◽  
Hui Chen

Abstract Background Plant transitions to land require robust cell walls for regulatory adaptations and to resist changing environments. Cell walls provide essential plasticity for plant cell division and defense, which are often conferred by the expansin superfamily with cell wall-loosening functions. However, the evolutionary mechanisms of expansin during plant terrestrialization are unclear. Results Here, we identified 323 expansin proteins in 12 genomes from algae to angiosperms. Phylogenetic evolutionary, structural, motif gain and loss and Ka/Ks analyses indicated that highly conserved expansin proteins were already present in algae and expanded and purified after plant terrestrialization. We found that the expansion of the FtEXPA subfamily was caused by duplication events and that the functions of certain duplicated genes may have differentiated. More importantly, we generated space-time expression profiles and finally identified five differentially expressed FtEXPs in both large and small fruit Tartary buckwheat that may regulate fruit size by responding to indoleacetic acid. Conclusions A total of 323 expansin proteins from 12 representative plants were identified in our study during terrestrialization, and the expansin family that originated from algae expanded rapidly after the plants landed. The EXPA subfamily has more members and conservative evolution in angiosperms. FtEXPA1, FtEXPA11, FtEXPA12, FtEXPA19 and FtEXPA24 can respond to indole-3-acetic acid (IAA) signals and regulate fruit development. Our study provides a blueprint for improving the agronomic traits of Tartary buckwheat and a reference for defining the evolutionary history of the expansin family during plant transitions to land.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kaixuan Zhang ◽  
Ming He ◽  
Yu Fan ◽  
Hui Zhao ◽  
Bin Gao ◽  
...  

Abstract Background Tartary buckwheat (Fagopyrum tataricum) is a nutritionally balanced and flavonoid-rich crop plant that has been in cultivation for 4000 years and is now grown globally. Despite its nutraceutical and agricultural value, the characterization of its genetics and its domestication history is limited. Results Here, we report a comprehensive database of Tartary buckwheat genomic variation based on whole-genome resequencing of 510 germplasms. Our analysis suggests that two independent domestication events occurred in southwestern and northern China, resulting in diverse characteristics of modern Tartary buckwheat varieties. Genome-wide association studies for important agricultural traits identify several candidate genes, including FtUFGT3 and FtAP2YT1 that significantly correlate with flavonoid accumulation and grain weight, respectively. Conclusions We describe the domestication history of Tartary buckwheat and provide a detailed resource of genomic variation to allow for genomic-assisted breeding in the improvement of elite cultivars.


Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 635-645 ◽  
Author(s):  
David A Kirby ◽  
Wolfgang Stephan

Abstract We surveyed sequence variation and divergence for the entire 5972-bp transcriptional unit of the white gene in 15 lines of Drosophila melanogaster and one line of D. simulans. We found a very high degree of haplotypic structuring for the polymorphisms in the 3′ half of the gene, as opposed to the polymorphisms in the 5′ half. To determine the evolutionary mechanisms responsible for this pattern, we sequenced a 1612-bp segment of the white gene from an additional 33 lines of D. melanogaster from a European and a North American population. This 1612-bp segment encompasses an 834bp region of the white gene in which the polymorphisms form high frequency haplotypes that cannot be explained by a neutral equilibrium model of molecular evolution. The small number of recombinants in the 834bp region suggests epistatic selection as the cause of the haplotypic structuring, while an investigation of nucleotide diversity supports a directional selection hypothesis. A multi-locus selection model that combines features from both-hypotheses and takes the recent history of D. melanogaster into account may be the best explanation for these data.


Hemoglobin ◽  
2018 ◽  
pp. 94-123
Author(s):  
Jay F. Storz

Chapter 5 provides an overview of the evolutionary history of the globin gene superfamily and places the evolution of vertebrate-specific globins in phylogenetic context. The duplication and functional divergence of globin genes has promoted key physiological innovations in respiratory gas transport and other physiological functions during animal evolution. A combination of both tandem gene duplication and whole-genome duplication contributed to the diversification of vertebrate globins. Phylogenetic reconstructions arrange vertebrate globins into those that derive from vertebrate-specific duplications (cytoglobin, globin E, globin Y, and the independently derived myoglobin-like and hemoglobin-like genes of jawed vertebrates and jawless fishes [lampreys and hagfish]) and those that derive from far more ancient duplication events that predate the divergence between deuterostomes and protostomes (androglobin, globin X, and neuroglobin). Tracing the evolutionary history of deuterostome globins reveals evidence for the repeated culling of ancestral diversity, followed by lineage-specific diversification of surviving gene lineages via repeated rounds of duplication and divergence.


2019 ◽  
Vol 286 (1897) ◽  
pp. 20182929 ◽  
Author(s):  
Elena A. Ritschard ◽  
Robert R. Fitak ◽  
Oleg Simakov ◽  
Sönke Johnsen

Coleoid cephalopods show unique morphological and neural novelties, such as arms with tactile and chemosensory suckers and a large complex nervous system. The evolution of such cephalopod novelties has been attributed at a genomic level to independent gene family expansions, yet the exact association and the evolutionary timing remain unclear. In the octopus genome, one such expansion occurred in the G-protein-coupled receptors (GPCRs) repertoire, a superfamily of proteins that mediate signal transduction. Here, we assessed the evolutionary history of this expansion and its relationship with cephalopod novelties. Using phylogenetic analyses, at least two cephalopod- and two octopus-specific GPCR expansions were identified. Signatures of positive selection were analysed within the four groups, and the locations of these sequences in the Octopus bimaculoides genome were inspected. Additionally, the expression profiles of cephalopod GPCRs across various tissues were extracted from available transcriptomic data. Our results reveal the evolutionary history of cephalopod GPCRs. Unexpanded cephalopod GPCRs shared with other bilaterians were found to be mainly nervous tissue specific. By contrast, duplications that are shared between octopus and the bobtail squid or specific to the octopus' lineage generated copies with divergent expression patterns devoted to tissues outside of the brain. The acquisition of novel expression domains was accompanied by gene order rearrangement through either translocation or duplication and gene loss. Lastly, expansions showed signs of positive selection and some were found to form tandem clusters with shared conserved expression profiles in cephalopod innovations such as the axial nerve cord. Altogether, our results contribute to the understanding of the molecular and evolutionary history of signal transduction and provide insights into the role of this expansion during the emergence of cephalopod novelties and/or adaptations.


2018 ◽  
Author(s):  
Juan C. Opazo ◽  
Kattina Zavala

AbstractGrowth differentiation factors 1 (GDF1) and 3 (GDF3) are members of the transforming growth factor superfamily (TGF-β) that is involved in fundamental early-developmental processes that are conserved across vertebrates. The evolutionary history of these genes is still under debate due to ambiguous definitions of homologous relationships among vertebrates. Thus, the goal of this study was to unravel the evolution of the GDF1 and GDF3 genes of vertebrates, emphasizing the understanding of homologous relationships and their evolutionary origin. Surprisingly, our results revealed that the GDF1 and GDF3 genes found in amphibians and mammals are the products of independent duplication events of an ancestral gene in the ancestor of each of these lineages. The main implication of this result is that the GDF1 and GDF3 genes of amphibians and mammals are not 1:1 orthologs. In other words, genes that participate in fundamental processes during early development have been reinvented two independent times during the evolutionary history of tetrapods.


1987 ◽  
Vol 65 (4) ◽  
pp. 779-785 ◽  
Author(s):  
Joseph S. Nelson

Systematics, defined here as the study of the evolutionary history of life, plays a vital role in biology. Together with studies of evolutionary mechanisms, it gives special meaning to biology; it is the unifying force in biology. As a result of recent developments in techniques useful to systematics and in philosophical approaches to systematics, it will be possible for vertebrate systematics to make major advances. Comparative morphological studies of extant and extinct species will play the dominant role in our understanding of the overall pattern of vertebrate phylogeny. For extant species, data from immunological, electrophoretic, and amino acid sequence studies will be important, but the major advances will come from studies of mitochondrial DNA and DNA–DNA hybridization. Examples of phylogenetic controversies that should be resolved in the next 25 years concern the following: the ancestral group of jawed vertebrates, the relationships of Latimeria, the ancestral group of tetrapods, the interrelationships of birds and mammals to each other, and the closest living relatives of man. Both cladistic and synthetic classifications will survive; each serves a useful purpose in translating phylogenetic ideas. Systematics, together with evolution, is a fundamental aspect of biology and should be included in the undergraduate program of all biology students; all biology departments should have a research program in systematics involving graduate students and staff. In addition, museums are a vital part of biology departments, in both their teaching and research functions, and their existence within universities must be nourished.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 9010-9010
Author(s):  
E. Hiyama ◽  
H. Yamaoka ◽  
A. Kamimatsuse ◽  
M. Onitake ◽  
T. Sueda ◽  
...  

9010 Background: Neuroblastoma is a biologically and genetically heterogeneous tumor and demonstrates favorable or unfavorable outcomes. However, the number of subgroups in neuroblastoma and natural history of each subgroup remain unclear. In Japan, nation-wide neuroblasotma mass-screening (MS) project had been performed on 6-month-old babies for 20 years that might have detected almost all neuroblastomas including regressing/ maturing tumors developed in this period. We surveyed more than 3,600 neuroblasotma cases including approximately 2,000 MS detecting cases. In this study, we examined genetic alterations in the representative cases using genome-wide SNP array and compared with the clinical courses. Methods: Genomic DNA was extracted from 198 neuroblastoma samples. SNP array (Affimetrix GeneChip Human mapping Array100K) was used to determine genome-wide aberrations. Chromosome aberrations were confirmed by BAC array and FISH examination. Expression profiles of these tumors were also examined using whole genome microarray (Codelink and Affimetrix Array U133 plus2). Results: SNP arrays could frequently identify chromosomal aberrations and allelic imbalances including 1p and 11q loss and MYCN amplification in unfavorable tumors. Then, we broadly classified the chromosome aberrations in neuroblastoma into four types: whole gain/loss type, partial gain/loss type, MYCN amplified type, and silent type with no large alterations. Almost all tumors with whole gain/loss type showed favorable prognosis, while MYCN amplified type and partial gain/loss type showed unfavorable outcome. In 32 tumors with silent type, 18 unfavorable tumors had small deletions and/or gains in 1p, 2p, 3p, 11q, and/or 17q but the remaining 16 favorable cases did not. The expression analysis of the unfavorable tumors showed high expression of several genes (DDX1, NAG, NME1, MAC30) in these loci. Conclusions: Genome-wide genetic analysis classified neuroblastoma into four types, which are useful to predict the outcome of patients. In the silent type, unfavorable tumors revealed several genes to predict the outcome of the patients. These data provided important candidates of indicators for risk assessment and of therapeutic targets for unfavorable neuroblastoma. No significant financial relationships to disclose.


2012 ◽  
Vol 2012 ◽  
pp. 1-24 ◽  
Author(s):  
Vaishali Katju

The gene duplication process has exhibited far greater promiscuity in the creation of paralogs with novel exon-intron structures than anticipated even by Ohno. In this paper I explore the history of the field, from the neo-Darwinian synthesis through Ohno’s formulation of the canonical model for the evolution of gene duplicates and culminating in the present genomic era. I delineate the major tenets of Ohno’s model and discuss its failure to encapsulate the full complexity of the duplication process as revealed in the era of genomics. I discuss the diverse classes of paralogs originating from both DNA- and RNA-mediated duplication events and their evolutionary potential for assuming radically altered functions, as well as the degree to which they can function unconstrained from the pressure of gene conversion. Lastly, I explore theoretical population-genetic considerations of how the effective population size (Ne) of a species may influence the probability of emergence of genes with radically altered functions.


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