Welcome To Website IAS

Hot news
Achievement

Independence Award

- First Rank - Second Rank - Third Rank

Labour Award

- First Rank - Second Rank -Third Rank

National Award

 - Study on food stuff for animal(2005)

 - Study on rice breeding for export and domestic consumption(2005)

VIFOTEC Award

- Hybrid Maize by Single Cross V2002 (2003)

- Tomato Grafting to Manage Ralstonia Disease(2005)

- Cassava variety KM140(2010)

Centres
Website links
Vietnamese calendar
Library
Visitors summary
 Curently online :  3
 Total visitors :  4447810

Microbial evolutionary strategies in a dynamic ocean
Monday, 2020/03/23 | 08:33:07

Nathan G. Walworth, Emily J. Zakem,  John P. Dunne,  Sinéad Collins, and Naomi M. Levine

PNAS March 17, 2020 117 (11) 5943-5948

Significance

Robust predictions of future changes in global biogeochemical cycling require an understanding of how microorganisms adapt to stressful and changing environments. In the ocean, rates of adaptation will be a function of both evolutionary timescales and physical dynamics. However, little is known about this interaction. We examined evolutionary dynamics of marine microbes by combining a model of microbial adaptation with varying selection pressures with a high-resolution ocean circulation model. A trade-off emerged between two evolutionary strategies: (i) ability to adapt plastically to short-term environmental fluctuations with delayed genetic adaptation and (ii) more rapid genetic adaptation with limited response to short-term environmental fluctuations. This trade-off determines evolutionary timescales and provides a foundation for understanding distributions of microbial traits and biogeochemistry.

Abstract

Marine microbes form the base of ocean food webs and drive ocean biogeochemical cycling. Yet little is known about the ability of microbial populations to adapt as they are advected through changing conditions. Here, we investigated the interplay between physical and biological timescales using a model of adaptation and an eddy-resolving ocean circulation climate model. Two criteria were identified that relate the timing and nature of adaptation to the ratio of physical to biological timescales. Genetic adaptation was impeded in highly variable regimes by nongenetic modifications but was promoted in more stable environments. An evolutionary trade-off emerged where greater short-term nongenetic transgenerational effects (low-γ strategy) enabled rapid responses to environmental fluctuations but delayed genetic adaptation, while fewer short-term transgenerational effects (high-γ strategy) allowed faster genetic adaptation but inhibited short-term responses. Our results demonstrate that the selective pressures for organisms within a single water mass vary based on differences in generation timescales resulting in different evolutionary strategies being favored. Organisms that experience more variable environments should favor a low-γ strategy. Furthermore, faster cell division rates should be a key factor in genetic adaptation in a changing ocean. Understanding and quantifying the relationship between evolutionary and physical timescales is critical for robust predictions of future microbial dynamics.

 

See https://www.pnas.org/content/117/11/5943

Fig. 1:

Illustrative example of model dynamics for a high-γ (A) and low-γ (B) simulation. Fitness changes (black line) are primarily driven by HT modifications (purple line) in the high-γ simulation and by both HT and LT (blue line) modifications in the low-γ simulation. The time-to-sweep (τsweep) is longer for the low-γ simulation (B) than the high-γ simulation (A). White shading denotes the “new” environment while gray shading denotes the “ancestral” environment.

Back      Print      View: 39

[ Other News ]___________________________________________________
  • Transgenic pig carrying green fluorescent proteasomes
  • Ammonia oxidation pathways and nitrifier denitrification are significant sources of N2O and NO under low oxygen availability
  • Genetic analysis and mapping of genes for resistance to multiple strains of Soybean mosaic virus in a single resistant soybean accession PI 96983
  • Genomic assay reveals tolerance of DNA damage by both translesion DNA synthesis and homology-dependent repair in mammalian cells
  • IRRI Scientists Develop Super Salt-tolerant Rice
  • A dominant major locus in chromosome 9 of rice (Oryza sativa L.) confers tolerance to 48°C high temperature at seedling stage.
  • Source-sink dynamics and proteomic reprogramming under elevated night temperature and their impact on rice yield and grain quality
  • Gene similarity networks provide tools for understanding eukaryote origins and evolution
  • Suppression of Arabidopsis protophloem differentiation and root meristem growth by CLE45 requires the receptor-like kinase BAM3
  • Bacillus subtilis biofilm induction by plant polysaccharides
  • Scientists Re-evaluate Nutrient Uptake of Modern Corn
  • A Dominant Major Locus in Chromosome 9 of Rice (Oryza sativa L.) Confers Tolerance to 48 °C High Temperature at Seedling Stage
  • Scientists Identify Proton Pathway in Photosynthesis
  • Scientists Find Way to Increase Phosphorus Content in Wheat
  • De novo next-generation sequencing, assembling and annotation of Arachis hypogaea L. Spanish botanical type whole plant transcriptome
  • Targeted linkage map densification to improve cell wall related QTL detection and interpretation in maize
  • Fine-mapping and molecular marker development for Pi56(t), a NBS-LRR gene conferring broad-spectrum resistance to Magnaporthe oryzae in rice
  • Genome-wide comparative diversity uncovers multiple targets of selection for improvement in hexaploid wheat landraces and cultivars
  • Smoke-derived karrikin perception by the α/β-hydrolase KAI2 from Arabidopsis
  • USDA Approves Testing of Pink Pineapple
Designed & Powered by WEBSO CO.,LTD