scholarly journals Mechanisms of ecological divergence with gene flow in a reef-building coral on an isolated atoll in Western Australia

2021 ◽  
Author(s):  
Luke Thomas ◽  
Jim Underwood ◽  
Noah H Rose ◽  
Zach L Fuller ◽  
Laurence Dugal ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Gene Flow ◽  
Western Australia ◽  
Cell Signalling ◽  
Extreme Environments ◽  
Common Garden ◽  
Allele Frequencies ◽  
Its2 Region ◽  
Strong Linkage Disequilibrium

Understanding the mechanisms driving phenotypic variation in traits facing intensified selection from climate change is a crucial step in developing effective conservation and restoration initiatives. This is particularly true for reef-building corals, which are among the most vulnerable to climate change and are in dramatic decline globally. At the Rowley Shoals in Western Australia, the prominent reef flat becomes exposed on low tide and the stagnant water in the shallow atoll lagoons heats up, creating a natural laboratory for characterising the mechanisms that control phenotypic responses to different environments. We combined whole genome re-sequencing, common garden heat stress experiments, transcriptome-wide gene expression analyses, and symbiont metabarcoding to explore the mechanisms that facilitate survival in contrasting habitat conditions. Our data show that, despite high gene flow between habitats, spatially varying selection drives subtle shifts in allele frequencies at hundreds of loci. These changes were concentrated into several islands of divergence spanning hundreds of SNPs that showed strong linkage disequilibrium and were associated with a coordinated increase in minor allele frequencies in corals taken from the lagoon habitat, where the range of environmental conditions is greatest. Common garden heat stress assays showed individuals from the lagoon exhibited higher bleaching resistance than colonies from the reef slope, and RNAseq identified pronounced physiological differences between the corals from the two habitats, primarily associated with molecular pathways including cell signalling, ion transport and metabolism. Despite the pronounced physioloigical and environmental differences between habitats, metabarcoding of the Symbiodiniaceae ITS2 region revealed all colonies to be associated exclusively with the genus Cladocopium, with no detectable differences between habitats. This study contributes to the growing number of studies documenting the complex mechanisms that facilitate coral survival in extreme environments, and showcases the utility of combining multiple sequencing techniques to unravel complex climate-related traits.

scholarly journals Genomic footprints of local adaptation along elevation gradients associate with present phenotypic variation in teosintes

2019 ◽  
Author(s):  
M-A. Fustier ◽  
N.E. Martínez-Ainsworth ◽  
A. Venon ◽  
H. Corti ◽  
A. Rousselet ◽  
...  
Keyword(s):  
Climate Change ◽  
Gene Flow ◽  
Local Adaptation ◽  
Phenotypic Variation ◽  
Allele Frequencies ◽  
Maize Breeding ◽  
Elevation Gradients ◽  
Common Gardens ◽  
Molecular Determinants ◽  
Set Up

AbstractLocal adaptation across species range is widespread. Yet, much has to be discovered on its environmental drivers, the underlying functional traits and their molecular determinants. Because elevation gradients display continuous environmental changes at a short geographical scale, they provide an exceptional opportunity to investigate these questions. Here, we used two common gardens to phenotype 1664 plants from 11 populations of annual teosintes. These populations were sampled across two elevation gradients in Mexico. Our results point to a syndrome of adaptation to altitude with the production of offspring that flowered earlier, produced less tillers, and larger, longer and heavier grains with increasing elevation. We genotyped these plants for 178 outlier single nucleotide polymorphisms (SNPs), which had been chosen because they displayed excess of allele differentiation and/or correlation with environmental variables in six populations with contrasted altitudes. A high proportion of outlier SNPs associated with the phenotypic variation of at least one trait. We tested phenotypic pairwise correlations between traits, and found that the higher the correlation, the greater the number of common associated SNPs. In addition, allele frequencies at 87 of the outlier SNPs correlated with an environmental component best summarized by altitudinal variation on a broad sample of 28 populations. Chromosomal inversions were enriched for both phenotypically-associated and environmentally-correlated SNPs. Altogether, our results are consistent with the set-up of an altitudinal syndrome promoted by local adaptation of teosinte populations in the face of gene flow. We showed that pleiotropy is pervasive and potentially has constrained the evolution of traits. Finally, we recovered variants underlying phenotypic variation at adaptive traits. Because elevation mimics climate change through space, these variants may be relevant for future maize breeding.Author summaryAcross their native range, species encounter a diversity of habitats promoting local adaptation of geographically distributed populations. While local adaptation is widespread, much has yet to be discovered about the conditions of its emergence, the targeted traits, their molecular determinants and the underlying ecological drivers. Here we employed a reverse ecology approach, combining phenotypes and genotypes, to mine the determinants of local adaptation of teosinte populations distributed along two steep altitudinal gradients in Mexico. Evaluation of 11 populations in two common gardens located at mid-elevation pointed to the set-up of an altitudinal syndrome, in spite of gene flow. We scanned genomes to identify loci with allele frequencies shifts along elevation. Interestingly, variation at these loci was commonly associated to variation of phenotypes. Because elevation mimics climate change through space, these variants may be relevant for future maize breeding.

scholarly journals Genomic assessment of local adaptation in dwarf birch to inform assisted gene flow

2019 ◽  
Author(s):  
James S. Borrell ◽  
Jasmin Zohren ◽  
Richard A. Nichols ◽  
Richard J. A. Buggs
Keyword(s):  
Climate Change ◽  
Gene Flow ◽  
Local Adaptation ◽  
Environmental Variables ◽  
Allele Frequencies ◽  
Species Range ◽  
Conservation Action ◽  
Mean Temperature ◽  
Diurnal Range ◽  
Dwarf Birch

AbstractWhen populations of a rare species are small, isolated and declining under climate change, some populations may become locally maladapted. Detecting this maladaptation may allow effective rapid conservation interventions, even if based on incomplete knowledge. Population maladaptation may be estimated by finding genome-environment associations (GEA) between allele frequencies and environmental variables across a local species range, and identifying populations whose allele frequencies do not fit with these trends. We can then design assisted gene flow strategies for maladapted populations, to adjust their allele frequencies, entailing lower levels of intervention than with undirected conservation action. Here, we investigate this strategy in Scottish populations of the montane plant dwarf birch (Betula nana). In genome-wide single nucleotide polymorphism (SNP) data we found 267 significant associations between SNP loci and environmental variables. We ranked populations by maladaptation estimated using allele frequency deviation from the general trends at these loci; this gave a different prioritization for conservation action than the Shapely Index, which seeks to preserve rare neutral variation. Populations estimated to be maladapted in their allele frequencies at loci associated with annual mean temperature were found to have reduced catkin production. Using an environmental niche modelling (ENM) approach, we found annual mean temperature (35%), and mean diurnal range (15%), to be important predictors of the dwarf birch distribution. Intriguingly, there was a significant correlation between the number of loci associated with each environmental variable in the GEA, and the importance of that variable in the ENM. Together, these results suggest that the same environmental variables determine both adaptive genetic variation and species range in Scottish dwarf birch. We suggest an assisted gene flow strategy that aims to maximize the local adaptation of dwarf birch populations under climate change by matching allele frequencies to current and future environments.

scholarly journals Isolation of Metrosideros (ʻOhiʻa) Taxa on Oʻahu Increases with Elevation and Extreme Environments

2019 ◽  
Vol 111 (1) ◽  
pp. 103-118 ◽  
Author(s):  
Elizabeth A Stacy ◽  
Tomoko Sakishima ◽  
Heaven Tharp ◽  
Neil Snow
Keyword(s):  
Gene Flow ◽  
Isolation By Distance ◽  
Extreme Environments ◽  
Common Garden ◽  
Metrosideros Polymorpha ◽  
Elevation Gradients ◽  
Principal Role ◽  
Generation Times ◽  
Limited Dispersal ◽  
Limited Gene Flow

Abstract Species radiations should be facilitated by short generation times and limited dispersal among discontinuous populations. Hawaii’s hyper-diverse, landscape-dominant tree, Metrosideros, is unique among the islands’ radiations for its massive populations that occur continuously over space and time within islands, its exceptional capacity for gene flow by both pollen and seed, and its extended life span (ca. >650 years). Metrosideros shows the greatest phenotypic and microsatellite DNA diversity on Oʻahu, where taxa occur in tight sympatry or parapatry in mesic and montane wet forest on 2 volcanoes. We document the nonrandom distributions of 12 taxa (including unnamed morphotypes) along elevation gradients, measure phenotypes of ~6-year-old common-garden plants of 8 taxa to verify heritability of phenotypes, and examine genotypes of 476 wild adults at 9 microsatellite loci to compare the strengths of isolation across taxa, volcanoes, and distance. All 8 taxa retained their diagnostic phenotypes in the common garden. Populations were isolated by taxon to a range of degrees (pairwise FST between taxa: 0.004–0.267), and there was no pattern of isolation by distance or by elevation; however, significant isolation between volcanoes was observed within monotypic species, suggesting limited gene flow between volcanoes. Among the infraspecific taxa of Metrosideros polymorpha, genetic diversity and isolation significantly decreased and increased, respectively, with elevation. Overall, 5 of the 6 most isolated taxa were associated with highest elevations or otherwise extreme environments. These findings suggest a principal role for selection in the origin and maintenance of the exceptional diversity that occurs within continuous Metrosideros stands on Oʻahu.

scholarly journals Urban Geometry Optimization to Mitigate Climate Change: Towards Energy-Efficient Buildings

2020 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Hatem Mahmoud ◽  
Ayman Ragab
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Efficiency ◽  
Energy Demand ◽  
Building Blocks ◽  
Climate Projections ◽  
Climate Change Scenarios ◽  
Urban Geometry ◽  
Outdoor Spaces ◽  
The Impact

The density of building blocks and insufficient greenery in cities tend to contribute dramatically not only to increased heat stress in the built environment but also to higher energy demand for cooling. Urban planners should, therefore, be conscious of their responsibility to reduce energy usage of buildings along with improving outdoor thermal efficiency. This study examines the impact of numerous proposed urban geometry cases on the thermal efficiency of outer spaces as well as the energy consumption of adjacent buildings under various climate change scenarios as representative concentration pathways (RCP) 4.5 and 8.5 climate projections for New Aswan city in 2035. The investigation was performed at one of the most underutilized outdoor spaces on the new campus of Aswan University in New Aswan city. The potential reduction of heat stress was investigated so as to improve the thermal comfort of the investigated outdoor spaces, as well as energy savings based on the proposed strategies. Accordingly, the most appropriate scenario to be adopted to cope with the inevitable climate change was identified. The proposed scenarios were divided into four categories of parameters. In the first category, shelters partially (25–50% and 75%) covering the streets were used. The second category proposed dividing the space parallel or perpendicular to the existing buildings. The third category was a hybrid scenario of the first and second categories. In the fourth category, a green cover of grass was added. A coupling evaluation was applied utilizing ENVI-met v4.2 and Design-Builder v4.5 to measure and improve the thermal efficiency of the outdoor space and reduce the cooling energy. The results demonstrated that it is better to cover outdoor spaces with 50% of the overall area than transform outdoor spaces into canyons.

scholarly journals Safety verification of genetically modified rice morphology, hereditary nature, and quality

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dong Won Jeon ◽  
Jae-Ryoung Park ◽  
Yoon-Hee Jang ◽  
Eun-Gyeong Kim ◽  
Taehun Ryu ◽  
...  
Keyword(s):  
Climate Change ◽  
Gene Flow ◽  
Negative Impact ◽  
Genetically Modified ◽  
Germination Rate ◽  
Future Climate Change ◽  
Yield Reduction ◽  
Drought Tolerant ◽  
Gm Plants ◽  
Gm Rice

Abstract Background The drought environment occurs frequently due to the unpredictable future climate change, and drought has a direct negative impact on crops, such as yield reduction. Drought events are random, frequent, and persistent. Molecular breeding can be used to create drought-tolerant food crops, but the safety of genetically modified (GM) plants must be demonstrated before they can be adopted. In this research, the environmental risk of drought-tolerant GM rice was explored by assessing phenotype and gene flow. Drought resistance genes CaMsrB2 inserted HV8 and HV23 were used as GM rice to analyze the possibility of various agricultural traits and gene flow along with non-GM rice. Results When the traits 1000-grain weight, grain length/width, and yield, were compared with GM rice and non-GM rice, all agricultural traits of GM rice and non-GM rice were the same. In addition, when the germination rate, viviparous germination rate, pulling strength, and bending strength were compared to analyze the possibility of weediness, all characteristic values of GM rice and non-GM rice were the same. Protein, amylose, and moisture, the major nutritional elements of rice, were also the same. Conclusions The results of this research are that GM rice and non-GM rice were the same in all major agricultural traits except for the newly assigned characteristics, and no gene mobility occurred. Therefore, GM rice can be used as a means to solve the food problem in response to the unpredictable era of climate change in the future.

Climate change impacts on water yields and demands in south-western Australia

2012 ◽  
Vol 475 ◽  
pp. 488-498 ◽  
Author(s):  
Don McFarlane ◽  
Roy Stone ◽  
Sasha Martens ◽  
Jonathan Thomas ◽  
Richard Silberstein ◽  
...  
Keyword(s):  
Climate Change ◽  
Western Australia ◽  
Climate Change Impacts

Influence of occupational heat stress on labour productivity – a case study from Chennai, India

2016 ◽  
Vol 65 (2) ◽  
pp. 245-255 ◽  
Author(s):  
Jeremiah Chinnadurai ◽  
Vidhya Venugopal ◽  
Kumaravel P ◽  
Paramesh R
Keyword(s):  
Climate Change ◽  
Heart Rate ◽  
Heat Stress ◽  
Pearson Correlation ◽  
Labour Productivity ◽  
Productivity Loss ◽  
Threshold Limit Value ◽  
Control Measures ◽  
Economic Losses ◽  
Content Type

Purpose – Raise in temperatures due to climate change is likely to increase the heat stress in occupations that are physically exerting and performed outdoors which might potentially have adverse health and productivity consequences. The purpose of this paper is to estimate the productivities in construction work under the influence of heat stress using the predicted mean vote (PMV) index. Design/methodology/approach – Field studies were conducted during May 2014 which is summer time in Chennai. Continuous heart rate of workers and wet bulb globe temperature measurements are conducted for workers engaged in different jobs in construction. Metabolic rates and the workload of the workers from heart rate were calculated using the ISO method 8996 and the PMV values are calculated using the tool developed by Malchaire based on the method ISO 7730. Direct observations and personal interviews were conducted to substantiate the productivity estimations. Findings – The results showed that workers working outdoors with moderate and heavy workload exceeded the threshold limit value of 28°C and had adverse productivity impacts (18-35 per cent productivity loss), whereas the workers engaged in light indoor work was not affected by heat stress and consequent productivity losses. The productivity estimations using the PMV index is found to be statistically significant for three types of construction works (Pearson correlation coefficient value of −0.78) and also correlated well with the observations and self-reported productivities of the workers. Originality/value – The method used in this paper provides a scientific and reliable estimation of the productivities which may benefit the industry to set realistic project completion goals in hot weather and also implement interventions and policies to protect workers’ health. Developing adaptive strategies and implementing control measures are the need of the hour to protect worker’s health and economic losses in the face of climate change.

Bedeutung des Innenraumklimas und Hitzestress im Zuge des Klimawandels/Importance of indoor climate and heat stress in the era of climate change

Gefahrstoffe ◽  
2021 ◽  
Vol 81 (07-08) ◽  
pp. 279-282
Author(s):  
Thomas Ackermann ◽  
Andreas Matzarakis
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Indoor Climate ◽  
Gesetzliche Vorgaben

Hitzewellen, die in Folge des Klimawandels häufiger, intensiver und länger auftreten werden, führen zu einer Belastung des Menschen, insbesondere in Städten. Die dort befindlichen Gebäude und Flächen heizen sich durch die Sonneneinstrahlung tagsüber auf, kühlen aber im Vergleich zum weniger verdichteten Umland während der Nachtphase geringfügiger ab. Die sich daraus ergebenden langanhaltend hohen Temperaturen wirken sich besonders belastend auf den menschlichen Körper aus und verursachen negative Folgen, wie den Anstieg der Mortalität. Um mit den künftig intensiveren Hitzewellen besser umgehen zu können und um Gesundheitsrisiken zu vermeiden, sollten für städtische Räume und dort vor allem für Innenräume Anpassungsmaßnahmen entwickelt werden. Darüber hinaus sollten Regelungen getroffen werden, die sowohl im Zusammenhang mit dem Energieverbrauch bzw. Wärmeschutz stehen, als auch gesetzliche Vorgaben bezüglich Grenz- und Schwellenwerten berücksichtigen und dabei nicht nur auf der Lufttemperatur beruhen, sondern thermische Indizes, die auf den Wärmeaustausch des Menschen und die thermischen Auswirkungen besser quantitativ beschreiben können.

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