scholarly journals Quantitative and population genomics suggest a broad role of stay‐green loci in the drought adaptation of sorghum

2021 ◽  
Author(s):  
Jacques M. Faye ◽  
Eyanawa A. Akata ◽  
Bassirou Sine ◽  
Cyril Diatta ◽  
Ndiaga Cisse ◽  
...  
Keyword(s):  
Population Genomics ◽  
Drought Adaptation ◽  
Stay Green ◽  
Broad Role

scholarly journals Quantitative and population genomics suggest a broad role of staygreen loci in the drought adaptation of sorghum

2021 ◽  
Author(s):  
Jacques M Faye ◽  
Eyanawa A Akata ◽  
Bassirou Sine ◽  
Cyril Diatta ◽  
Daniel Fonceka ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Yield Components ◽  
Population Genomics ◽  
Association Studies ◽  
Tolerance Index ◽  
Genome Wide Association Studies ◽  
Drought Adaptation ◽  
Stay Green ◽  
Broad Role

Drought is a major constraint on plant productivity globally. Sorghum (Sorghum bicolor) landraces have evolved in drought-prone regions, but the genetics of their adaptation is not yet understood. Loci underlying stay-green post-flowering drought tolerance (Stg), have been identified in a temperate breeding line, but their role in drought adaptation of tropical sorghum is to be elucidated. We phenotyped 590 diverse sorghum accessions from West Africa under field-based managed drought stress, pre-flowering (WS1) and post-flowering (WS2) over several years and conducted genome-wide association studies (GWAS). Broad-sense heritability for grain and biomass yield components was high (33-92%) across environments. There was a significant correlation between stress tolerance index (STI) for grain weight across WS1 and WS2. GWAS revealed that SbZfl1 and SbCN12, orthologs of maize flowering genes, likely underlie flowering time variation under these conditions. GWAS further identified associations (n = 134) for STI and drought effects on yield components, including 16 putative pleiotropic associations. Thirty of the associations colocalized with Stg1-4 loci and had large effects. Seven lead associations, including some within Stg1, overlapped with positive selection outliers. Our findings reveal natural genetic variation for drought tolerance-related traits, and suggest a broad role of Stg loci in drought adaptation of sorghum.

scholarly journals The demography and population genomics of evolutionary transitions to self-fertilization in plants

2014 ◽  
Vol 369 (1648) ◽  
pp. 20130344 ◽  
Author(s):  
Spencer C. H. Barrett ◽  
Ramesh Arunkumar ◽  
Stephen I. Wright
Keyword(s):  
Mating System ◽  
Population Genomics ◽  
Molecular Data ◽  
Reproductive Assurance ◽  
Evolutionary Transitions ◽  
Cast Doubt ◽  
Self Fertilization ◽  
Loss Of Diversity ◽  
Linked Selection

The evolution of self-fertilization from outcrossing has occurred on numerous occasions in flowering plants. This shift in mating system profoundly influences the morphology, ecology, genetics and evolution of selfing lineages. As a result, there has been sustained interest in understanding the mechanisms driving the evolution of selfing and its environmental context. Recently, patterns of molecular variation have been used to make inferences about the selective mechanisms associated with mating system transitions. However, these inferences can be complicated by the action of linked selection following the transition. Here, using multilocus simulations and comparative molecular data from related selfers and outcrossers, we demonstrate that there is little evidence for strong bottlenecks associated with initial transitions to selfing, and our simulation results cast doubt on whether it is possible to infer the role of bottlenecks associated with reproductive assurance in the evolution of selfing. They indicate that the effects of background selection on the loss of diversity and efficacy of selection occur rapidly following the shift to high selfing. Future comparative studies that integrate explicit ecological and genomic details are necessary for quantifying the independent and joint effects of selection and demography on transitions to selfing and the loss of genetic diversity.

scholarly journals Cytokinin Sensing in Bacteria

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 186
Author(s):  
Samar Kabbara ◽  
Baptiste Bidon ◽  
Jaafar Kilani ◽  
Marwan Osman ◽  
Monzer Hamze ◽  
...  
Keyword(s):  
Cell Signaling ◽  
Host Plant ◽  
Plant Hormones ◽  
Cellular Signaling ◽  
Phytopathogenic Bacteria ◽  
Signaling Mechanisms ◽  
Plant Chemicals ◽  
First Time ◽  
Broad Role

Although it has long been known that bacteria detect and react to plant chemicals to establish an interaction, the cellular signaling mechanisms involved in these perception processes have hitherto remained obscure. Some exciting recent advances in the field have described, for the first time, how some phytopathogenic bacteria sense the host plant hormones, cytokinins. These discoveries not only advance the understanding of cell signaling circuitries engaged in cytokinin sensing in non-plant organisms, but also increase our knowledge of the broad role of these ancient molecules in regulating intra- and interspecific communications.

scholarly journals A Whole Genome Re-Sequencing Based GWA Analysis Reveals Candidate Genes Associated with Ivermectin Resistance in Haemonchus contortus

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 367 ◽  
Author(s):  
Sawar Khan ◽  
Ayesha Nisar ◽  
Jianqi Yuan ◽  
Xiaoping Luo ◽  
Xueqin Dou ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Haemonchus Contortus ◽  
Population Genomics ◽  
Small Ruminants ◽  
Track Record ◽  
Genome Wide ◽  
Signatures Of Selection ◽  
Parasitic Worms ◽  
Important Parasite

The most important and broad-spectrum drug used to control the parasitic worms to date is ivermectin (IVM). Resistance against IVM has emerged in parasites, and preserving its efficacy is now becoming a serious issue. The parasitic nematode Haemonchus contortus (Rudolphi, 1803) is economically an important parasite of small ruminants across the globe, which has a successful track record in IVM resistance. There are growing evidences regarding the multigenic nature of IVM resistance, and although some genes have been proposed as candidates of IVM resistance using lower magnification of genome, the genetic basis of IVM resistance still remains poorly resolved. Using the full magnification of genome, we herein applied a population genomics approach to characterize genome-wide signatures of selection among pooled worms from two susceptible and six ivermectin-resistant isolates of H. contortus, and revealed candidate genes under selection in relation to IVM resistance. These candidates also included a previously known IVM-resistance-associated candidate gene HCON_00148840, glc-3. Finally, an RNA-interference-based functional validation assay revealed the HCON_00143950 as IVM-tolerance-associated gene in H. contortus. The possible role of this gene in IVM resistance could be detoxification of xenobiotic in phase I of xenobiotic metabolism. The results of this study further enhance our understanding on the IVM resistance and continue to provide further evidence in favor of multigenic nature of IVM resistance.

scholarly journals Charge-driven condensation of RNA and proteins suggests broad role of phase separation in cytoplasmic environments

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Bercem Dutagaci ◽  
Grzegorz Nawrocki ◽  
Joyce Goodluck ◽  
Ali Akbar Ashkarran ◽  
Charles G Hoogstraten ◽  
...  
Keyword(s):  
Phase Separation ◽  
Molecular Size ◽  
Biological Macromolecules ◽  
Separation Processes ◽  
Cellular Environment ◽  
Polymer Properties ◽  
Protein Components ◽  
Separation Of Mixtures ◽  
Broad Role

Phase separation processes are increasingly being recognized as important organizing mechanisms of biological macromolecules in cellular environments. Well-established drivers of phase separation are multi-valency and intrinsic disorder. Here, we show that globular macromolecules may condense simply based on electrostatic complementarity. More specifically, phase separation of mixtures between RNA and positively charged proteins is described from a combination of multiscale computer simulations with microscopy and spectroscopy experiments. Phase diagrams were mapped out as a function of molecular concentrations in experiment and as a function of molecular size and temperature via simulations. The resulting condensates were found to retain at least some degree of internal dynamics varying as a function of the molecular composition. The results suggest a more general principle for phase separation that is based primarily on electrostatic complementarity without invoking polymer properties as in most previous studies. Simulation results furthermore suggest that such phase separation may occur widely in heterogenous cellular environment between nucleic acid and protein components.

scholarly journals The broad role of Nkx3.2 in the development of the zebrafish axial skeleton

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255953
Author(s):  
Laura Waldmann ◽  
Jake Leyhr ◽  
Hanqing Zhang ◽  
Caroline Öhman-Mägi ◽  
Amin Allalou ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Morphological Changes ◽  
Skeletal Development ◽  
Axial Skeleton ◽  
Chondrocyte Maturation ◽  
Weberian Apparatus ◽  
Jaw Joint ◽  
Context Specific ◽  
Broad Role

The transcription factor Nkx3.2 (Bapx1) is an important chondrocyte maturation inhibitor. Previous Nkx3.2 knockdown and overexpression studies in non-mammalian gnathostomes have focused on its role in primary jaw joint development, while the function of this gene in broader skeletal development is not fully described. We generated a mutant allele of nkx3.2 in zebrafish with CRISPR/Cas9 and applied a range of techniques to characterize skeletal phenotypes at developmental stages from larva to adult, revealing loss of the jaw joint, fusions in bones of the occiput, morphological changes in the Weberian apparatus, and the loss or deformation of bony elements derived from basiventral cartilages of the vertebrae. Axial phenotypes are reminiscent of Nkx3.2 knockout in mammals, suggesting that the function of this gene in axial skeletal development is ancestral to osteichthyans. Our results highlight the broad role of nkx3.2 in zebrafish skeletal development and its context-specific functions in different skeletal elements.

scholarly journals A review of COVID-19 vaccines strategies and anti-vaxxers theories

2021 ◽  
Vol 22 (2) ◽  
pp. 117-123
Author(s):  
A. Adesokan ◽  
M.A. Obeid
Keyword(s):  
Nous Avons ◽  
Scientific Basis ◽  
Viral Transmission ◽  
Mots Clés ◽  
Conspiracy Theories ◽  
The Public ◽  
Record Time ◽  
The World ◽  
Broad Role

In what is a global record time of getting the COVID-19 vaccines available within 11 months, the world has equally been faced with several myths and conspiracy theories dissuading the public from accepting vaccination as an important measure in the response to the pandemic. We reviewed the leading conspiracy theories and balanced these with the scientific basis of viral transmission and replication and the broad role of vaccination in tackling this challenge. We briefly examined the design of the leading vaccines, and provided recommendations for worldwide COVID-19 distribution, acceptance and use. Keywords: COVID-19, vaccine, anti-vaxxer, review   French Title: Un examen des stratégies de vaccins COVID-19 et des théories anti-vaxxers Dans ce qui est un temps record mondial pour obtenir les vaccins COVID-19 disponibles en 11 mois, le monde a également été confronté à plusieurs mythes et théories du complot dissuadant le public d'accepter la vaccination comme une mesure importante dans la réponse à la pandémie. Nous avons passé en revue les principales théories du complot et les avons équilibrées avec la base scientifique de la transmission et de la réplication virales et le rôle général de la vaccination dans la lutte contre ce défi. Nous avons brièvement examiné la conception des principaux vaccins et formulé des recommandations pour la distribution, l'acceptation et l'utilisation du COVID19 dans le monde. Mots clés: COVID-19, vaccin, anti-vaxxer, revue

scholarly journals Gene flow mediates the role of sex chromosome meiotic drive during complex speciation

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Colin D Meiklejohn ◽  
Emily L Landeen ◽  
Kathleen E Gordon ◽  
Thomas Rzatkiewicz ◽  
Sarah B Kingan ◽  
...  
Keyword(s):  
Gene Flow ◽  
Sex Chromosomes ◽  
Population Genomics ◽  
Sex Chromosome ◽  
Hybrid Sterility ◽  
Sequence Divergence ◽  
Meiotic Drive ◽  
Hybrid Male ◽  
Local Sequence

During speciation, sex chromosomes often accumulate interspecific genetic incompatibilities faster than the rest of the genome. The drive theory posits that sex chromosomes are susceptible to recurrent bouts of meiotic drive and suppression, causing the evolutionary build-up of divergent cryptic sex-linked drive systems and, incidentally, genetic incompatibilities. To assess the role of drive during speciation, we combine high-resolution genetic mapping of X-linked hybrid male sterility with population genomics analyses of divergence and recent gene flow between the fruitfly species, Drosophila mauritiana and D. simulans. Our findings reveal a high density of genetic incompatibilities and a corresponding dearth of gene flow on the X chromosome. Surprisingly, we find that a known drive element recently migrated between species and, rather than contributing to interspecific divergence, caused a strong reduction in local sequence divergence, undermining the evolution of hybrid sterility. Gene flow can therefore mediate the effects of selfish genetic elements during speciation.

Sign in / Sign up

Export Citation Format

Share Document