scholarly journals Genomic basis of parallel adaptation varies with divergence in Arabidopsis and its relatives

2021 ◽  
Vol 118 (21) ◽  
pp. e2022713118
Author(s):  
Magdalena Bohutínská ◽  
Jakub Vlček ◽  
Sivan Yair ◽  
Benjamin Laenen ◽  
Veronika Konečná ◽  
...  

Parallel adaptation provides valuable insight into the predictability of evolutionary change through replicated natural experiments. A steadily increasing number of studies have demonstrated genomic parallelism, yet the magnitude of this parallelism varies depending on whether populations, species, or genera are compared. This led us to hypothesize that the magnitude of genomic parallelism scales with genetic divergence between lineages, but whether this is the case and the underlying evolutionary processes remain unknown. Here, we resequenced seven parallel lineages of two Arabidopsis species, which repeatedly adapted to challenging alpine environments. By combining genome-wide divergence scans with model-based approaches, we detected a suite of 151 genes that show parallel signatures of positive selection associated with alpine colonization, involved in response to cold, high radiation, short season, herbivores, and pathogens. We complemented these parallel candidates with published gene lists from five additional alpine Brassicaceae and tested our hypothesis on a broad scale spanning ∼0.02 to 18 My of divergence. Indeed, we found quantitatively variable genomic parallelism whose extent significantly decreased with increasing divergence between the compared lineages. We further modeled parallel evolution over the Arabidopsis candidate genes and showed that a decreasing probability of repeated selection on the same standing or introgressed alleles drives the observed pattern of divergence-dependent parallelism. We therefore conclude that genetic divergence between populations, species, and genera, affecting the pool of shared variants, is an important factor in the predictability of genome evolution.

Author(s):  
Magdalena Bohutínská ◽  
Jakub Vlček ◽  
Sivan Yair ◽  
Benjamin Laenen ◽  
Veronika Konečná ◽  
...  

AbstractParallel adaptation provides valuable insight into the predictability of evolutionary change through replicated natural experiments. A steadily increasing number of studies have demonstrated genomic parallelism, yet the magnitude of this parallelism varies depending on whether populations, species or genera are compared. This led us to hypothesize that the magnitude of genomic parallelism scales with genetic divergence between lineages, but whether this is the case and the underlying evolutionary processes remain unknown. Here, we resequenced seven parallel lineages of two Arabidopsis species which repeatedly adapted to challenging alpine environments. By combining genome-wide divergence scans with model-based approaches we detected a suite of 151 genes that show parallel signatures of positive selection associated with alpine colonization, involved in response to cold, high radiation, short season, herbivores and pathogens. We complemented these parallel candidates with published gene lists from five additional alpine Brassicaceae and tested our hypothesis on a broad scale spanning ~ 0.02 to 18 million years of divergence. Indeed, we found quantitatively variable genomic parallelism whose extent significantly decreased with increasing divergence between the compared lineages. We further modeled parallel evolution over the Arabidopsis candidate genes and showed that a decreasing probability of repeated selection of the same standing or introgressed alleles drives the observed pattern of divergence-dependent parallelism. We therefore conclude that genetic divergence between populations, species and genera, affecting the pool of shared variants, is an important factor in the predictability of genome evolution.Significance statementRepeated evolution tends to be more predictable. The impressive spectrum of recent reports on genomic parallelism, however, revealed that the fraction of the genome that evolves in parallel largely varies, possibly reflecting different evolutionary scales investigated. Here, we demonstrate divergence-dependent parallelism using a comprehensive genome-wide dataset comprising 12 cases of parallel alpine adaptation and identify decreasing probability of adaptive re-use of genetic variation as the major underlying cause. This finding empirically demonstrates that evolutionary predictability is scale dependent and suggests that availability of pre-existing variation drives parallelism within and among populations and species. Altogether, our results inform the ongoing discussion about the (un)predictability of evolution, relevant for applications in pest control, nature conservation, or the evolution of pathogen resistance.


2020 ◽  
Vol 11 ◽  
Author(s):  
Adam Knotek ◽  
Veronika Konečná ◽  
Guillaume Wos ◽  
Doubravka Požárová ◽  
Gabriela Šrámková ◽  
...  

Parallel evolution provides powerful natural experiments for studying repeatability of evolution and genomic basis of adaptation. Well-documented examples from plants are, however, still rare, as are inquiries of mechanisms driving convergence in some traits while divergence in others. Arabidopsis arenosa, a predominantly foothill species with scattered morphologically distinct alpine occurrences is a promising candidate. Yet, the hypothesis of parallelism remained untested. We sampled foothill and alpine populations in all regions known to harbor the alpine ecotype and used SNP genotyping to test for repeated alpine colonization. Then, we combined field surveys and a common garden experiment to quantify phenotypic parallelism. Genetic clustering by region but not elevation and coalescent simulations demonstrated parallel origin of alpine ecotype in four mountain regions. Alpine populations exhibited parallelism in height and floral traits which persisted after two generations in cultivation. In contrast, leaf traits were distinctive only in certain region(s), reflecting a mixture of plasticity and genetically determined non-parallelism. We demonstrate varying degrees and causes of parallelism and non-parallelism across populations and traits within a plant species. Parallel divergence along a sharp elevation gradient makes A. arenosa a promising candidate for studying genomic basis of adaptation.


Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
J. S. Park ◽  
B. N. Juterbock

The electric and thermal properties of the resistor material in an automotive spark plug should be stable during its service lifetime. Containing many elements and many phases, this material has a very complex microstructure. Elemental mapping with an electron microprobe can reveal the distribution of all relevant elements throughout the sample. In this work, it is demonstrated that the charge-up effect, which would distort an electron image and, therefore, is normally to be avoided in an electron imaging work, could be used to advantage to reveal conductive and resistive zones in a sample. Its combination with elemental mapping can provide valuable insight into the underlying conductivity mechanism of the resistor.This work was performed in a CAMECA SX-50 microprobe. The spark plug used in the present report was a commercial product taken from the shelf. It was sectioned to expose the cross section of the resistor. The resistor was known not to contain the precious metal Au as checked on the carbon coated sample. The sample was then stripped of carbon coating and re-coated with Au.


2018 ◽  
Author(s):  
Qi Li ◽  
Adam J. Zaczek ◽  
Timothy M. Korter ◽  
J. Axel Zeitler ◽  
Michael T. Ruggiero

<div>Understanding the nature of the interatomic interactions present within the pores of metal-organic frameworks</div><div>is critical in order to design and utilize advanced materials</div><div>with desirable applications. In ZIF-8 and its cobalt analogue</div><div>ZIF-67, the imidazolate methyl-groups, which point directly</div><div>into the void space, have been shown to freely rotate - even</div><div>down to cryogenic temperatures. Using a combination of ex-</div><div>perimental terahertz time-domain spectroscopy, low-frequency</div><div>Raman spectroscopy, and state-of-the-art ab initio simulations,</div><div>the methyl-rotor dynamics in ZIF-8 and ZIF-67 are fully charac-</div><div>terized within the context of a quantum-mechanical hindered-</div><div>rotor model. The results lend insight into the fundamental</div><div>origins of the experimentally observed methyl-rotor dynamics,</div><div>and provide valuable insight into the nature of the weak inter-</div><div>actions present within this important class of materials.</div>


2020 ◽  
Vol 16 (5) ◽  
pp. 557-567
Author(s):  
Aparoop Das ◽  
Anshul Shakya ◽  
Surajit Kumar Ghosh ◽  
Udaya P. Singh ◽  
Hans R. Bhat

Background: Plants of the genus Inula are perennial herbs of the family Asteraceae. This genus includes more than 100 species, widely distributed throughout Europe, Africa and Asia including India. Many of them are indicated in traditional medicine, e.g., in Ayurveda. This review explores chemical constituents, medicinal uses and pharmacological actions of Inula species. Methods: Major databases and research and review articles retrieved through Scopus, Web of Science, and Medline were consulted to obtain information on the pharmacological activities of the genus Inula published from 1994 to 2017. Results: Inula species are used either alone or as an important ingredient of various formulations to cure dysfunctions of the cardiovascular system, respiratory system, urinary system, central nervous system and digestive system, and for the treatment of asthma, diabetes, cancers, skin disorders, hepatic disease, fungal and bacterial infections. A range of phytochemicals including alkaloids, essential and volatile oils, flavonoids, terpenes, and lactones has been isolated from herbs of the genus Inula, which might possibly explain traditional uses of these plants. Conclusion: The present review is focused on chemical constituents, medicinal uses and pharmacological actions of Inula species and provides valuable insight into its medicinal potential.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Evan S. Littleton ◽  
Madison L. Childress ◽  
Michaela L. Gosting ◽  
Ayana N. Jackson ◽  
Shihoko Kojima

AbstractCell-autonomous circadian system, consisting of core clock genes, generates near 24-h rhythms and regulates the downstream rhythmic gene expression. While it has become clear that the percentage of rhythmic genes varies among mouse tissues, it remains unclear how this variation can be generated, particularly when the clock machinery is nearly identical in all tissues. In this study, we sought to characterize circadian transcriptome datasets that are publicly available and identify the critical component(s) involved in creating this variation. We found that the relative amplitude of 13 genes and the average level of 197 genes correlated with the percentage of cycling genes. Of those, the correlation of Rorc in both relative amplitude and the average level was one of the strongest. In addition, the level of Per2AS, a novel non-coding transcript that is expressed at the Period 2 locus, was also linearly correlated, although with a much lesser degree compared to Rorc. Overall, our study provides insight into how the variation in the percentage of clock-controlled genes can be generated in mouse tissues and suggests that Rorc and potentially Per2AS are involved in regulating the amplitude of circadian transcriptome output.


Author(s):  
Le Wang ◽  
Fei Sun ◽  
Zi Yi Wan ◽  
Baoqing Ye ◽  
Yanfei Wen ◽  
...  

Abstract Resolving the genomic basis underlying phenotypic variations is a question of great importance in evolutionary biology. However, understanding how genotypes determine the phenotypes is still challenging. Centuries of artificial selective breeding for beauty and aggression resulted in a plethora of colors, long fin varieties, and hyper-aggressive behavior in the air-breathing Siamese fighting fish (Betta splendens), supplying an excellent system for studying the genomic basis of phenotypic variations. Combining whole genome sequencing, QTL mapping, genome-wide association studies and genome editing, we investigated the genomic basis of huge morphological variation in fins and striking differences in coloration in the fighting fish. Results revealed that the double tail, elephant ear, albino and fin spot mutants each were determined by single major-effect loci. The elephant ear phenotype was likely related to differential expression of a potassium ion channel gene, kcnh8. The albinotic phenotype was likely linked to a cis-regulatory element acting on the mitfa gene and the double tail mutant was suggested to be caused by a deletion in a zic1/zic4 co-enhancer. Our data highlight that major loci and cis-regulatory elements play important roles in bringing about phenotypic innovations and establish Bettas as new powerful model to study the genomic basis of evolved changes.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Carla De Angelis ◽  
Alicia B. Byrne ◽  
Rebecca Morrow ◽  
Jinghua Feng ◽  
Thuong Ha ◽  
...  

Abstract Background Periventricular nodular heterotopia (PNH) is a malformation of cortical development characterized by nodules of abnormally migrated neurons. The cause of posteriorly placed PNH is not well characterised and we present a case that provides insights into the cause of posterior PNH. Case presentation We report a fetus with extensive posterior PNH in association with biallelic variants in LAMC3. LAMC3 mutations have previously been shown to cause polymicrogyria and pachygyria in the occipital cortex, but not PNH. The occipital location of PNH in our case and the proposed function of LAMC3 in cortical development suggest that the identified LAMC3 variants may be causal of PNH in this fetus. Conclusion We hypothesise that this finding extends the cortical phenotype associated with LAMC3 and provides valuable insight into genetic cause of posterior PNH.


Economies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 42
Author(s):  
Maria Adamakou ◽  
Dimitris Kallioras ◽  
George Petrakos

Universities are emerging growth determinants. This is so as, in addition to the fulfillment of their traditional role in teaching and (basic) research, universities, as aptly described within the helix framework, are expected to engage in regional development processes. The paper aims to detect trends of convergence among EU universities in terms of performance. To the best of our knowledge, this topic has not hitherto been examined. The empirical analysis of the paper covers the period 2014–2021, utilizes data obtained from URAP (University Ranking by Academic Performance), and employs the methodological approach of convergence clubs. The findings of the paper provide valuable insight into both theory and policy-making. We conclude that despite the unification of EU educational space, trends of divergence among EU universities are still present, and notable divisions still remain. Consequently, this indicates that the impact of EU universities on the formation of spatial disparities across EU space is not neutral.


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 737
Author(s):  
Ji-Eun Jeong ◽  
Binna Seol ◽  
Han-Seop Kim ◽  
Jae-Yun Kim ◽  
Yee-Sook Cho

Although comparative genome-wide transcriptomic analysis has provided insight into the biology of human induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs), the distinct alternative splicing (AS) signatures of iMSCs remain elusive. Here, we performed Illumina RNA sequencing analysis to characterize AS events in iMSCs compared with tissue-derived MSCs. A total of 4586 differentially expressed genes (|FC| > 2) were identified between iMSCs and umbilical cord blood-derived MSCs (UCB-MSCs), including 2169 upregulated and 2417 downregulated genes. Of these, 164 differentially spliced events (BF > 20) in 112 genes were identified between iMSCs and UCB-MSCs. The predominant type of AS found in iMSCs was skipped exons (43.3%), followed by retained introns (19.5%), alternative 3′ (15.2%) and 5′ (12.8%) splice sites, and mutually exclusive exons (9.1%). Functional enrichment analysis showed that the differentially spliced genes (|FC| > 2 and BF > 20) were mainly enriched in functions associated with focal adhesion, extracellular exosomes, extracellular matrix organization, cell adhesion, and actin binding. Splice isoforms of selected genes including TRPT1, CNN2, and AP1G2, identified in sashimi plots, were further validated by RT-PCR analysis. This study provides valuable insight into the biology of iMSCs and the translation of mechanistic understanding of iMSCs into therapeutic applications.


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