scholarly journals Genome-wide signatures of plastid-nuclear coevolution point to repeated perturbations of plastid proteostasis systems across angiosperms

2020 ◽  
Author(s):  
Evan S. Forsythe ◽  
Alissa M. Williams ◽  
Daniel B. Sloan
Keyword(s):  
Nuclear Genome ◽  
Protein Translation ◽  
Nuclear Genes ◽  
Sequence Evolution ◽  
Cellular Functions ◽  
Transmission Modes ◽  
Chloroplast Genomes ◽  
Genome Wide ◽  
Phylogenomic Analyses ◽  
Post Transcriptional Regulation

AbstractNuclear and plastid (chloroplast) genomes experience different mutation rates, levels of selection, and transmission modes, yet key cellular functions depend on coordinated interactions between proteins encoded in both genomes. Functionally related proteins often show correlated changes in rates of sequence evolution across a phylogeny (evolutionary rate covariation or ERC), offering a means to detect previously unidentified suites of coevolving and cofunctional genes. We performed phylogenomic analyses across angiosperm diversity, scanning the nuclear genome for genes that exhibit ERC with plastid genes. As expected, the strongest hits are highly enriched for plastid-targeted proteins, providing evidence that cytonuclear interactions affect rates of molecular evolution at genome-wide scales. Many identified nuclear genes function in post-transcriptional regulation and the maintenance of protein homeostasis (proteostasis), including protein translation (in both the plastid and cytosol), import, quality control and turnover. We also identified nuclear genes that exhibit strong signatures of coevolution with the plastid genome but lack organellar-targeting annotations, making them candidates for having previously undescribed roles in plastids. In sum, our genome-wide analyses reveal that plastid- nuclear coevolution extends beyond the intimate molecular interactions within chloroplast enzyme complexes and may be driven by frequent rewiring of the machinery responsible for maintenance of plastid proteostasis in angiosperms.

scholarly journals Genome-wide signatures of plastid-nuclear coevolution point to repeated perturbations of plastid proteostasis systems across angiosperms

2021 ◽  
Author(s):  
Evan S Forsythe ◽  
Alissa M Williams ◽  
Daniel B Sloan
Keyword(s):  
Nuclear Genome ◽  
Protein Translation ◽  
Nuclear Genes ◽  
Sequence Evolution ◽  
Cellular Functions ◽  
Transmission Modes ◽  
Chloroplast Genomes ◽  
Genome Wide ◽  
Genes Encoding ◽  
Phylogenomic Analyses

Abstract Nuclear and plastid (chloroplast) genomes experience different mutation rates, levels of selection, and transmission modes, yet key cellular functions depend on their coordinated interactions. Functionally related proteins often show correlated changes in rates of sequence evolution across a phylogeny (evolutionary rate covariation or ERC), offering a means to detect previously unidentified suites of coevolving and cofunctional genes. We performed phylogenomic analyses across angiosperm diversity, scanning the nuclear genome for genes that exhibit ERC with plastid genes. As expected, the strongest hits were highly enriched for genes encoding plastid-targeted proteins, providing evidence that cytonuclear interactions affect rates of molecular evolution at genome-wide scales. Many identified nuclear genes functioned in post-transcriptional regulation and the maintenance of protein homeostasis (proteostasis), including protein translation (in both the plastid and cytosol), import, quality control and turnover. We also identified nuclear genes that exhibit strong signatures of coevolution with the plastid genome, but their encoded proteins lack organellar-targeting annotations, making them candidates for having previously undescribed roles in plastids. In sum, our genome-wide analyses reveal that plastid-nuclear coevolution extends beyond the intimate molecular interactions within chloroplast enzyme complexes and may be driven by frequent rewiring of the machinery responsible for maintenance of plastid proteostasis in angiosperms.

scholarly journals Transcriptional and Post-transcriptional Regulation of Organellar Gene Expression (OGE) and Its Roles in Plant Salt Tolerance

2019 ◽  
Vol 20 (5) ◽  
pp. 1056 ◽  
Author(s):  
Pedro Robles ◽  
Víctor Quesada
Keyword(s):  
Gene Expression ◽  
Salt Tolerance ◽  
Nuclear Genome ◽  
Nuclear Genes ◽  
Plant Tolerance ◽  
Adverse Conditions ◽  
Transport Chain ◽  
Genes Encoding ◽  
Plant Salt Tolerance ◽  
Post Transcriptional Regulation

Given their endosymbiotic origin, chloroplasts and mitochondria genomes harbor only between 100 and 200 genes that encode the proteins involved in organellar gene expression (OGE), photosynthesis, and the electron transport chain. However, as the activity of these organelles also needs a few thousand proteins encoded by the nuclear genome, a close coordination of the gene expression between the nucleus and organelles must exist. In line with this, OGE regulation is crucial for plant growth and development, and is achieved mainly through post-transcriptional mechanisms performed by nuclear genes. In this way, the nucleus controls the activity of organelles and these, in turn, transmit information about their functional state to the nucleus by modulating nuclear expression according to the organelles’ physiological requirements. This adjusts organelle function to plant physiological, developmental, or growth demands. Therefore, OGE must appropriately respond to both the endogenous signals and exogenous environmental cues that can jeopardize plant survival. As sessile organisms, plants have to respond to adverse conditions to acclimate and adapt to them. Salinity is a major abiotic stress that negatively affects plant development and growth, disrupts chloroplast and mitochondria function, and leads to reduced yields. Information on the effects that the disturbance of the OGE function has on plant tolerance to salinity is still quite fragmented. Nonetheless, many plant mutants which display altered responses to salinity have been characterized in recent years, and interestingly, several are affected in nuclear genes encoding organelle-localized proteins that regulate the expression of organelle genes. These results strongly support a link between OGE and plant salt tolerance, likely through retrograde signaling. Our review analyzes recent findings on the OGE functions required by plants to respond and tolerate salinity, and highlights the fundamental role that chloroplast and mitochondrion homeostasis plays in plant adaptation to salt stress.

scholarly journals RNA-seq highlights parallel and contrasting patterns in the evolution of the nuclear genome of holo-mycoheterotrophic plants

2017 ◽  
Author(s):  
M.I. Schelkunov ◽  
A.A. Penin ◽  
M.D. Logacheva
Keyword(s):  
Protein Import ◽  
Nuclear Genome ◽  
Nuclear Gene ◽  
Nuclear Genes ◽  
Rna Seq ◽  
Nucleotide Substitutions ◽  
Plastid Genomes ◽  
Genome Wide ◽  
Genes Encoding ◽  
Mycoheterotrophic Plants

Summary• While photosynthesis is the most notable trait of plants, several lineages of plants (so-called holo-heterotrophs) have adapted to obtain organic compounds from other sources. The switch to heterotrophy leads to profound changes at the morphological, physiological and genomic levels.• Here, we characterize the transcriptomes of three species representing two lineages of mycoheterotrophic plants: orchids (Epipogium aphyllum and Epipogium roseum) and Ericaceae (Hypopitys monotropa). Comparative analysis is used to highlight the parallelism between distantly related holo-heterotrophic plants.• In both lineages, we observed genome-wide elimination of nuclear genes that encode proteins related to photosynthesis, while systems associated with protein import to plastids as well as plastid transcription and translation remain active. Genes encoding components of plastid ribosomes that have been lost from the plastid genomes have not been transferred to the nuclear genomes; instead, some of the encoded proteins have been substituted by homologs. The nuclear genes of both Epipogium species accumulated mutations twice as rapidly as their photosynthetic relatives; in contrast, no increase in the substitution rate was observed in H.monotropa.• Holo-heterotrophy leads to profound changes in nuclear gene content. The observed increase in the rate of nucleotide substitutions is lineage specific, rather than a universal phenomenon among non-photosynthetic plants.

The Role of microRNAs in the Viral Infections

2019 ◽  
Vol 24 (39) ◽  
pp. 4659-4667 ◽  
Author(s):  
Mona Fani ◽  
Milad Zandi ◽  
Majid Rezayi ◽  
Nastaran Khodadad ◽  
Hadis Langari ◽  
...  
Keyword(s):  
Viral Infections ◽  
Rna Viruses ◽  
Regulation Of Gene Expression ◽  
Molecular Structures ◽  
Main Function ◽  
Cellular Functions ◽  
Viral Genes ◽  
Non Coding Rnas ◽  
Post Transcriptional Regulation

MicroRNAs (miRNAs) are non-coding RNAs with 19 to 24 nucleotides which are evolutionally conserved. MicroRNAs play a regulatory role in many cellular functions such as immune mechanisms, apoptosis, and tumorigenesis. The main function of miRNAs is the post-transcriptional regulation of gene expression via mRNA degradation or inhibition of translation. In fact, many of them act as an oncogene or tumor suppressor. These molecular structures participate in many physiological and pathological processes of the cell. The virus can also produce them for developing its pathogenic processes. It was initially thought that viruses without nuclear replication cycle such as Poxviridae and RNA viruses can not code miRNA, but recently, it has been proven that RNA viruses can also produce miRNA. The aim of this articles is to describe viral miRNAs biogenesis and their effects on cellular and viral genes.

scholarly journals Nuclear genome-wide associations with mitochondrial heteroplasmy

2021 ◽  
Vol 7 (12) ◽  
pp. eabe7520
Author(s):  
Priyanka Nandakumar ◽  
Chao Tian ◽  
Jared O’Connell ◽  
David Hinds ◽  
Andrew D. Paterson ◽  
...  
Keyword(s):  
Nuclear Genome ◽  
Multiple Roles ◽  
European Ancestry ◽  
Mitochondrial Transcription Factor ◽  
Genome Wide ◽  
Mtdna Sequence ◽  
Nuclear Component ◽  
Mitochondrial Transcription Factor A ◽  
Mitochondrial Heteroplasmy ◽  
The Stability

The role of the nuclear genome in maintaining the stability of the mitochondrial genome (mtDNA) is incompletely known. mtDNA sequence variants can exist in a state of heteroplasmy, which denotes the coexistence of organellar genomes with different sequences. Heteroplasmic variants that impair mitochondrial capacity cause disease, and the state of heteroplasmy itself is deleterious. However, mitochondrial heteroplasmy may provide an intermediate state in the emergence of novel mitochondrial haplogroups. We used genome-wide genotyping data from 982,072 European ancestry individuals to evaluate variation in mitochondrial heteroplasmy and to identify the regions of the nuclear genome that affect it. Age, sex, and mitochondrial haplogroup were associated with the extent of heteroplasmy. GWAS identified 20 loci for heteroplasmy that exceeded genome-wide significance. This included a region overlapping mitochondrial transcription factor A (TFAM), which has multiple roles in mtDNA packaging, replication, and transcription. These results show that mitochondrial heteroplasmy has a heritable nuclear component.

scholarly journals Chloroplast genomes in Populus (Salicaceae): comparisons from an intensively sampled genus reveal dynamic patterns of evolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiawei Zhou ◽  
Shuo Zhang ◽  
Jie Wang ◽  
Hongmei Shen ◽  
Bin Ai ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Population Level ◽  
Gene Content ◽  
Sequencing Data ◽  
Cellular Functions ◽  
Chloroplast Evolution ◽  
Chloroplast Genomes ◽  
Genome Features ◽  
Genome Annotations ◽  
Genome Analyses

AbstractThe chloroplast is one of two organelles containing a separate genome that codes for essential and distinct cellular functions such as photosynthesis. Given the importance of chloroplasts in plant metabolism, the genomic architecture and gene content have been strongly conserved through long periods of time and as such are useful molecular tools for evolutionary inferences. At present, complete chloroplast genomes from over 4000 species have been deposited into publicly accessible databases. Despite the large number of complete chloroplast genomes, comprehensive analyses regarding genome architecture and gene content have not been conducted for many lineages with complete species sampling. In this study, we employed the genus Populus to assess how more comprehensively sampled chloroplast genome analyses can be used in understanding chloroplast evolution in a broadly studied lineage of angiosperms. We conducted comparative analyses across Populus in order to elucidate variation in key genome features such as genome size, gene number, gene content, repeat type and number, SSR (Simple Sequence Repeat) abundance, and boundary positioning between the four main units of the genome. We found that some genome annotations were variable across the genus owing in part from errors in assembly or data checking and from this provided corrected annotations. We also employed complete chloroplast genomes for phylogenetic analyses including the dating of divergence times throughout the genus. Lastly, we utilized re-sequencing data to describe the variations of pan-chloroplast genomes at the population level for P. euphratica. The analyses used in this paper provide a blueprint for the types of analyses that can be conducted with publicly available chloroplast genomes as well as methods for building upon existing datasets to improve evolutionary inference.

scholarly journals Mitonuclear Coevolution, but Not Nuclear Compensation, Drives Evolution of OXPHOS Complexes in Bivalves

2021 ◽  
Author(s):  
Giovanni Piccinini ◽  
Mariangela Iannello ◽  
Guglielmo Puccio ◽  
Federico Plazzi ◽  
Justin C Havird ◽  
...  
Keyword(s):  
Specific Form ◽  
Nuclear Genes ◽  
Sequence Evolution ◽  
Bivalve Species ◽  
Mitochondrial Mutations ◽  
Site Specific ◽  
Mtdna Inheritance ◽  
Highly Correlated ◽  
Compensation Hypothesis ◽  
Mtdna Variability

Abstract In Metazoa, 4 out of 5 complexes involved in oxidative phosphorylation (OXPHOS) are formed by subunits encoded by both the mitochondrial (mtDNA) and nuclear (nuDNA) genomes, leading to the expectation of mito-nuclear coevolution. Previous studies have supported co-adaptation of mitochondria-encoded (mtOXPHOS) and nuclear-encoded OXPHOS (nuOXPHOS) subunits, often specifically interpreted with regard to the “nuclear compensation hypothesis”, a specific form of mitonuclear coevolution where nuclear genes compensate for deleterious mitochondrial mutations owing to less efficient mitochondrial selection. In this study we analysed patterns of sequence evolution of 79 OXPHOS subunits in 31 bivalve species, a taxon showing extraordinary mtDNA variability and including species with “doubly uniparental” mtDNA inheritance. Our data showed strong and clear signals of mitonuclear coevolution. NuOXPHOS subunits had concordant topologies with mtOXPHOS subunits, contrary to previous phylogenies based on nuclear genes lacking mt interactions. Evolutionary rates between mt and nuOXPHOS subunits were also highly correlated compared to non-OXPHOS-interacting nuclear genes. Nuclear subunits of chimeric OXPHOS complexes (I, III, IV, and V) also had higher dN/dS ratios than Complex II, which is formed exclusively by nuDNA-encoded subunits. However, we did not find evidence of nuclear compensation: mitochondria-encoded subunits showed similar dN/dS ratios compared to nuclear-encoded subunits, contrary to most previously studied bilaterian animals. Moreover, no site-specific signals of compensatory positive selection were detected in nuOXPHOS genes. Our analyses extend the evidence for mitonuclear coevolution to a new taxonomic group, but we propose a reconsideration of the nuclear compensation hypothesis.

scholarly journals Comparative analysis of chloroplast genomes of cultivars and wild species of sweetpotato (Ipomoea batatas [L.] Lam)

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shizhuo Xiao ◽  
Pan Xu ◽  
Yitong Deng ◽  
Xibin Dai ◽  
Lukuan Zhao ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Genetic Structure ◽  
Chloroplast Genome ◽  
Wild Species ◽  
Ipomoea Batatas ◽  
Nuclear Genome ◽  
Ipomoea Trifida ◽  
Chloroplast Markers ◽  
Chloroplast Genomes ◽  
Chloroplast Dna Markers

Abstract Background Sweetpotato (Ipomoea batatas [L.] Lam.) is an important food crop. However, the genetic information of the nuclear genome of this species is difficult to determine accurately because of its large genome and complex genetic background. This drawback has limited studies on the origin, evolution, genetic diversity and other relevant studies on sweetpotato. Results The chloroplast genomes of 107 sweetpotato cultivars were sequenced, assembled and annotated. The resulting chloroplast genomes were comparatively analysed with the published chloroplast genomes of wild species of sweetpotato. High similarity and certain specificity were found among the chloroplast genomes of Ipomoea spp. Phylogenetic analysis could clearly distinguish wild species from cultivars. Ipomoea trifida and Ipomoea tabascana showed the closest relationship with the cultivars, and different haplotypes of ycf1 could be used to distinguish the cultivars from their wild relatives. The genetic structure was analyzed using variations in the chloroplast genome. Compared with traditional nuclear markers, the chloroplast markers designed based on the InDels on the chloroplast genome showed significant advantages. Conclusions Comparative analysis of chloroplast genomes of 107 cultivars and several wild species of sweetpotato was performed to help analyze the evolution, genetic structure and the development of chloroplast DNA markers of sweetpotato.

scholarly journals TFEB Signalling-Related MicroRNAs and Autophagy

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 985
Author(s):  
Davide Corà ◽  
Federico Bussolino ◽  
Gabriella Doronzo
Keyword(s):  
Transcriptional Regulation ◽  
Stress Factors ◽  
Cellular Functions ◽  
Post Translational Modifications ◽  
Cellular Processes ◽  
Factor Deficiency ◽  
Transcription Factor Eb ◽  
Important Regulator ◽  
Response To Stress ◽  
Post Transcriptional Regulation

The oncogenic Transcription Factor EB (TFEB), a member of MITF-TFE family, is known to be the most important regulator of the transcription of genes responsible for the control of lysosomal biogenesis and functions, autophagy, and vesicles flux. TFEB activation occurs in response to stress factors such as nutrient and growth factor deficiency, hypoxia, lysosomal stress, and mitochondrial damage. To reach the final functional status, TFEB is regulated in multimodal ways, including transcriptional rate, post-transcriptional regulation, and post-translational modifications. Post-transcriptional regulation is in part mediated by miRNAs. miRNAs have been linked to many cellular processes involved both in physiology and pathology, such as cell migration, proliferation, differentiation, and apoptosis. miRNAs also play a significant role in autophagy, which exerts a crucial role in cell behaviour during stress or survival responses. In particular, several miRNAs directly recognise TFEB transcript or indirectly regulate its function by targeting accessory molecules or enzymes involved in its post-translational modifications. Moreover, the transcriptional programs triggered by TFEB may be influenced by the miRNA-mediated regulation of TFEB targets. Finally, recent important studies indicate that the transcription of many miRNAs is regulated by TFEB itself. In this review, we describe the interplay between miRNAs with TFEB and focus on how these types of crosstalk affect TFEB activation and cellular functions.

Evolution of the chloroplast genome and polymorphic ITS regions in Allium subg. Melanocrommyum

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 237-247 ◽  
Author(s):  
Ted HM Mes ◽  
Reinhard M Fritsch ◽  
Sven Pollner ◽  
Konrad Bachmann
Keyword(s):  
Concerted Evolution ◽  
Morphological Evolution ◽  
Restriction Analysis ◽  
Nuclear Genome ◽  
Restriction Enzymes ◽  
Border Region ◽  
Chloroplast Genomes ◽  
Central Asian ◽  
Its Regions ◽  
Chloroplast Haplotypes

Relationships based on PCR-RFLPs of non-coding regions of cpDNA indicate that some of the largest subgenera of the genus Allium and five of the largest sections of the Central Asian subg. Melanocrommyum are artificial. Internested synapomorphic mutations without homoplasy were found only in the chloroplast genomes of plants of subg. Melanocrommyum that occur in the border region of Tajikistan, Uzbekistan, Afghanistan, and Kyrgyzstan. Eighteen of 49 plants surveyed were polymorphic for their ITS regions. Even plants that had identical chloroplast genomes were polymorphic for nuclear ribosomal regions. These individuals had markedly different frequencies of ITS variants that were detected with various restriction enzymes. The geographic partitioning of chloroplast haplotypes and the fact that the ITS variants could not be ordered hierarchically can readily be envisioned to result from gene flow. Processes such as concerted evolution and parallel morphological evolution may also be partly responsible for the disconcordance of mutations in the chloroplast and nuclear genome. However, the chimeric nature of the nuclear ribosomal regions indicates that concerted evolution is not the dominating process in Allium subg. Melanocrommyum.Key words: polymorphic, phylogeny, restriction analysis.

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