scholarly journals Patterns of selection reveal shared molecular targets over short and long evolutionary timescales

2017 ◽  
Author(s):  
Jing Li ◽  
Ignacio Vázquez-García ◽  
Karl Persson ◽  
Asier González ◽  
Jia-Xing Yue ◽  
...  

AbstractStanding and de novo genetic variants can both drive adaptation to environmental changes, but their relative contributions and interplay remain poorly understood. Here we investigated the dynamics of drug adaptation in yeast populations with different levels of standing variation by experimental evolution coupled with time-resolved sequencing and phenotyping. We found a doubling of standing variation alone boost the adaptation by 64.1% and 51.5% in hydroxyuea and rapamycin respectively. The causative standing and de novo variants were selected on shared targets of RNR4 in hydroxyurea and TOR1, TOR2 in rapamycin. The standing and de novo TOR variants map to different functional domains and act via distinct mechanisms. Interestingly, standing TOR variants from two domesticated strains exhibited opposite resistance effects, reflecting lineage-specific functional divergence. This study provides a dynamic view on how standing and de novo variants interactively drive adaptation and deepens our understanding of clonally evolving diseases.

Author(s):  
Emilie J. Richards ◽  
Joseph A. McGirr ◽  
Jeremy R. Wang ◽  
Michelle E. St. John ◽  
Jelmer W. Poelstra ◽  
...  

AbstractTo investigate the origins and stages of vertebrate adaptive radiation, we reconstructed the spatial and temporal histories of genetic variants underlying major phenotypic axes of diversification from the genomes of 202 Caribbean pupfishes. Ancient standing variation from disparate spatial sources was reassembled into new combinations which are under strong selection for adaptation to novel trophic niches on only a single island throughout the Caribbean. This occurred in three stages: first, standing variation associated with feeding behavior swept, then standing variation regulating craniofacial development and pigmentation, and finally de novo variation for craniofacial development. Our results provide clear support for two longstanding hypotheses about adaptive radiation and demonstrate how ancient alleles maintained for millennia in distinct environmental refugia can be assembled into new adaptive combinations.One Sentence SummaryAncient origins of adaptive radiation


2021 ◽  
Vol 2 (1) ◽  
pp. 100383
Author(s):  
Nicholas S. Diab ◽  
Spencer King ◽  
Weilai Dong ◽  
Garrett Allington ◽  
Amar Sheth ◽  
...  

2017 ◽  
Vol 312 (6) ◽  
pp. G606-G614 ◽  
Author(s):  
Anna Zsófia Tóth ◽  
András Szabó ◽  
Eszter Hegyi ◽  
Péter Hegyi ◽  
Miklós Sahin-Tóth

Determination of fecal pancreatic elastase content by ELISA is a reliable, noninvasive clinical test for assessing exocrine pancreatic function. Despite the widespread use of commercial tests, their exact molecular targets remain poorly characterized. This study was undertaken to clarify which human pancreatic elastase isoforms are detected by the ScheBo Pancreatic Elastase 1 Stool Test and whether naturally occurring genetic variants influence the performance of this test. Using recombinantly expressed and purified human pancreatic proteinases, we found that the test specifically measured chymotrypsin-like elastases (CELA) 3A and 3B (CELA3A and CELA3B), while CELA2A was not detected. Inactive proelastases, active elastases, and autolyzed forms were detected with identical efficiency. CELA3B elicited approximately four times higher ELISA signal than CELA3A, and we identified Glu154in CELA3B as the critical determinant of detection. Common genetic variants of CELA3A and CELA3B had no effect on test performance, with the exception of the CELA3B variant W79R, which increased detection by 1.4-fold. Finally, none of the human trypsin and chymotrypsin isoforms were detected. We conclude that the ScheBo Pancreatic Elastase 1 Stool Test is specific for human CELA3A and CELA3B, with most of the ELISA signal attributable to CELA3B.NEW & NOTEWORTHY The ScheBo Pancreatic Elastase 1 Stool Test is widely used to assess pancreatic exocrine function, yet its molecular targets have been poorly defined. We demonstrate that, among the human pancreatic proteinases, the test measures the elastase isoform CELA3B and, to a lesser extent, CELA3A. Genetic variants of the human CELA3 isoforms have no significant effect on test performance.


2017 ◽  
Vol 64 (1) ◽  
pp. 62-74
Author(s):  
Marco Calabrò ◽  
Stefano Porcelli ◽  
Concetta Crisafulli ◽  
Sheng-Min Wang ◽  
Soo-Jung Lee ◽  
...  

Reproduction ◽  
2021 ◽  
Vol 162 (3) ◽  
pp. 181-191
Author(s):  
Jessica Ispada ◽  
Aldcejam Martins da Fonseca Junior ◽  
Otávio Luiz Ramos Santos ◽  
Camila Bruna de Lima ◽  
Erika Cristina dos Santos ◽  
...  

Metabolic and molecular profiles were reported as different for bovine embryos with distinct kinetics during the first cleavages. In this study, we used this same developmental model (fast vs slow) to determine if the relationship between metabolism and developmental kinetics affects the levels of acetylation or tri-methylation at histone H3 lysine 9 (H3K9ac and H3K9me3, respectively). Fast and slow developing embryos presented different levels of H3K9ac and H3K9me3 from the earliest stages of development (40 and 96 hpi) and up to the blastocyst stage. For H3K9me3, both groups of embryos presented a wave of demethylation and de novo methylation, although it was more pronounced in fast than slow embryos, resulting in blastocysts with higher levels of this mark. The H3K9ac reprogramming profile was distinct between kinetics groups. While slow embryos presented a wave of deacetylation, followed by an increase in this mark at the blastocyst stage, fast embryos reduced this mark throughout all the developmental stages studied. H3K9me3 differences corresponded to writer and eraser transcript levels, while H3K9ac patterns were explained by metabolism-related gene expression. To verify if metabolic differences could alter levels of H3K9ac, embryos were cultured with sodium-iodoacetate (IA) or dichloroacetate (DCA) to disrupt the glycolytic pathway or increase acetyl-CoA production, respectively. IA reduced H3K9ac while DCA increased H3K9ac in blastocysts. Concluding, H3K9me3 and H3K9ac patterns differ between embryos with different kinetics, the second one explained by metabolic pathways involved in acetyl-CoA production. So far, this is the first study demonstrating a relationship between metabolic differences and histone post-translational modifications in bovine embryos.


2018 ◽  
Vol 28 (1) ◽  
pp. 4-34 ◽  
Author(s):  
Maheshkumar P. Joshi ◽  
Ravi Kathuria ◽  
Sidhartha Das

This study examines a firm’s response to perceived changes in the environment, such as the growth of the digital era, at different levels of a firm—beginning with the adoption of corporate entrepreneurship (CE) down to process renewal (PR). We further explore if the technological intensity of a firm, high-tech or low-tech intensity, influences its choice of mode for organisational renewal (OR)—use of internal competence or outside acquisition—to exploit the opportunities created by the digital era. Using survey data from 170 firms, we test a sequential relationship among environmental changes (growth of the digital era), CE, OR and finally PR that involves operating procedures at the functional level. We conclude by identifying the study’s interdisciplinary contributions, which open new research avenues in the field of CE.


2021 ◽  
Author(s):  
Julia M. Kreiner ◽  
Amalia Caballero ◽  
Stephen I. Wright ◽  
John R. Stinchcombe

The relative role of hybridization, de novo evolution, and standing variation in weed adaptation to agricultural environments is largely unknown. In Amaranthus tuberculatus, a widespread North American agricultural weed, adaptation is likely influenced by recent secondary contact and admixture of two previously isolated subspecies. We characterized the extent of adaptation and phenotypic differentiation accompanying the spread of A. tuberculatus into agricultural environments and the contribution of subspecies divergence. We generated phenotypic and whole-genome sequence data from a manipulative common garden experiment, using paired samples from natural and agricultural populations. We found strong latitudinal, longitudinal, and sex differentiation in phenotypes, and subtle differences among agricultural and natural environments that were further resolved with ancestry-based inference. The transition into agricultural environments has favoured southwestern var. rudis ancestry that leads to higher biomass and environment-specific phenotypes: increased biomass and earlier flowering under reduced water availability, and reduced plasticity in fitness-related traits. We also detected de novo adaptation to agricultural habitats independent of ancestry effects, including marginally higher biomass and later flowering in agricultural populations, and a time to germination home advantage. Therefore, the invasion of A. tuberculatus into agricultural environments has drawn on adaptive variation across multiple timescales—through both preadaptation via the preferential sorting of var. rudis ancestry and de novo local adaptation.


2021 ◽  
Author(s):  
Guojie Zhong ◽  
Priyanka Ahimaz ◽  
Nicole A. Edwards ◽  
Jacob J. Hagen ◽  
Christophe Faure ◽  
...  

Esophageal atresias/tracheoesophageal fistulas (EA/TEF) are rare congenital anomalies caused by aberrant development of the foregut. Previous studies indicate that rare or de novo genetic variants significantly contribute to EA/TEF risk, and most individuals with EA/TEF do not have pathogenic genetic variants in established risk genes. To identify novel genetic contributions to EA/TEF, we performed whole genome sequencing of 185 trios (probands and parents) with EA/TEF, including 59 isolated and 126 complex cases with additional congenital anomalies and/or neurodevelopmental disorders. There was a significant burden of protein altering de novo coding variants in complex cases (p=3.3e-4), especially in genes that are intolerant of loss of function variants in the population. We performed simulation analysis of pathway enrichment based on background mutation rate and identified a number of pathways related to endocytosis and intracellular trafficking that as a group have a significant burden of protein altering de novo variants. We assessed 18 variants for disease causality using CRISPR-Cas9 mutagenesis in Xenopus and confirmed 13 with tracheoesophageal phenotypes. Our results implicate disruption of endosome-mediated epithelial remodeling as a potential mechanism of foregut developmental defects. This research may have implications for the mechanisms of other rare congenital anomalies.


2020 ◽  
Author(s):  
Eva L. Koch ◽  
Sonja H. Sbilordo ◽  
Frédéric Guillaume

AbstractIn presence of rapid environmental changes, it is of particular importance to assess the adaptive potential of populations, which is mostly determined by the additive genetic variation (VA) in fitness. In this study we used Tribolium castaneum (red flour beetles) to investigate its adaptive potential in three new environmental conditions (Dry, Hot, Hot-Dry). We tested for potential constraints that might limit adaptation, including negative genetic covariance between female and male fitness. Based on VA estimates for fitness, we expected the highest relative fitness increase in the most stressful condition Hot-Dry and similar increases in single stress conditions Dry and Hot. High adaptive potential in females in Hot was reduced by a negative covariance with male fitness. We tested adaptation to the three conditions after 20 generations of experimental evolution and found that observed adaptation mainly matched our predictions. Given that body size is commonly used as a proxy for fitness, we also tested how this trait and its genetic variance (including non-additive genetic variance) were impacted by environmental stress. In both traits, variances were sex and condition dependent, but they differed in their variance composition, cross-sex and cross-environment genetic covariances, as well as in the environmental impact on VA.


2021 ◽  
Vol 12 ◽  
Author(s):  
Valeria Longo ◽  
Alessandra Longo ◽  
Giorgia Adamo ◽  
Antonino Fiannaca ◽  
Sabrina Picciotto ◽  
...  

The 2,2’4,4’-tetrabromodiphenyl ether (PBDE-47) is one of the most prominent PBDE congeners detected in the environment and in animal and human tissues. Animal model experiments suggested the occurrence of PBDE-induced immunotoxicity leading to different outcomes and recently we demonstrated that this substance can impair macrophage and basophil activities. In this manuscript, we decided to further examine the effects induced by PBDE-47 treatment on innate immune response by looking at the intracellular expression profile of miRNAs as well as the biogenesis, cargo content and activity of human M(LPS) macrophage cell-derived small extracellular vesicles (sEVs). Microarray and in silico analysis demonstrated that PBDE-47 can induce some epigenetic effects in M(LPS) THP-1 cells modulating the expression of a set of intracellular miRNAs involved in biological pathways regulating the expression of estrogen-mediated signaling and immune responses with particular reference to M1/M2 differentiation. In addition to the cell-intrinsic modulation of intracellular miRNAs, we demonstrated that PBDE-47 could also interfere with the biogenesis of sEVs increasing their number and selecting a de novo population of sEVs. Moreover, PBDE-47 induced the overload of specific immune related miRNAs in PBDE-47 derived sEVs. Finally, culture experiments with naïve M(LPS) macrophages demonstrated that purified PBDE-47 derived sEVs can modulate macrophage immune response exacerbating the LPS-induced pro-inflammatory response inducing the overexpression of the IL-6 and the MMP9 genes. Data from this study demonstrated that PBDE-47 can perturb the innate immune response at different levels modulating the intracellular expression of miRNAs but also interfering with the biogenesis, cargo content and functional activity of M(LPS) macrophage cell-derived sEVs.


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