fundoshi TOPICS: Plant biology, cell biology, and more
3.4K views | +0 today
Follow
Your new post is loading...
Your new post is loading...
Rescooped by fundoshi from Transport in plants and fungi
Scoop.it!

Gibberellin Localization and Transport in Plants

Gibberellin Localization and Transport in Plants | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
Distribution patterns and finely-tuned concentration gradients of plant hormones govern plant growth and development. Gibberellin (GA) is a plant hormone regulating key processes in plants; many of them are of significant agricultural importance, such as seed germination, root and shoot elongation, flowering, and fruit patterning. Although studies have demonstrated that GA movement is essential for multiple developmental aspects, how GAs are transported throughout the plant and where exactly they accumulate remain largely unknown. Here, we summarize recent findings from studies of GA movement and localization, and discuss the importance of GA intermediates in long- and short-distance movement. We further review recently identified Arabidopsis GA transporters and highlight their complex specialization and robust functional redundancy in GA transport activity.
 

Via Kevin Garcia
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Mapping local variation in educational attainment across Africa

Nature: Mapping local variation in educational attainment across Africa | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: Educational attainment for women of reproductive age is linked to reduced child and maternal mortality, lower fertility and improved reproductive health. Comparable analyses of attainment exist only at the national level, potentially obscuring patterns in subnational inequality. Evidence suggests that wide disparities between urban and rural populations exist, raising questions about where the majority of progress towards the education targets of the Sustainable Development Goals is occurring in African countries. Here we explore within-country inequalities by predicting years of schooling across five by five kilometre grids, generating estimates of average educational attainment by age and sex at subnational levels. Despite marked progress in attainment from 2000 to 2015 across Africa, substantial differences persist between locations and sexes. These differences have widened in many countries, particularly across the Sahel. These high-resolution, comparable estimates improve the ability of decision-makers to plan the precisely targeted interventions that will be necessary to deliver progress during the era of the Sustainable Development Goals.

more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Global elevational diversity and diversification of birds

Nature: Global elevational diversity and diversification of birds | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
ABSTRACT: Mountain ranges harbour exceptionally high biodiversity, which is now under threat from rapid environmental change. However, despite decades of effort, the limited availability of data and analytical tools has prevented a robust and truly global characterization of elevational biodiversity gradients and their evolutionary origins1,2. This has hampered a general understanding of the processes involved in the assembly and maintenance of montane communities2,3,4. Here we show that a worldwide mid-elevation peak in bird richness is driven by wide-ranging species and disappears when we use a subsampling procedure that ensures even species representation in space and facilitates evolutionary interpretation. Instead, richness corrected for range size declines linearly with increasing elevation. We find that the more depauperate assemblages at higher elevations are characterized by higher rates of diversification across all mountain regions, rejecting the idea that lower recent diversification rates are the general cause of less diverse biota. Across all elevations, assemblages on mountains with high rates of past temperature change exhibit more rapid diversification, highlighting the importance of climatic fluctuations in driving the evolutionary dynamics of mountain biodiversity. While different geomorphological and climatic attributes of mountain regions have been pivotal in determining the remarkable richness gradients observed today, our results underscore the role of ongoing and often very recent diversification processes in maintaining the unique and highly adapted biodiversity of higher elevations.


more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Biomechanics of predator–prey arms race in lion, zebra, cheetah and impala

Nature: Biomechanics of predator–prey arms race in lion, zebra, cheetah and impala | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: The fastest and most manoeuvrable terrestrial animals are found in savannah habitats, where predators chase and capture running prey. Hunt outcome and success rate are critical to survival, so both predator and prey should evolve to be faster and/or more manoeuvrable. Here we compare locomotor characteristics in two pursuit predator–prey pairs, lion–zebra and cheetah–impala, in their natural savannah habitat in Botswana. We show that although cheetahs and impalas were universally more athletic than lions and zebras in terms of speed, acceleration and turning, within each predator–prey pair, the predators had 20% higher muscle fibre power than prey, 37% greater acceleration and 72% greater deceleration capacity than their prey. We simulated hunt dynamics with these data and showed that hunts at lower speeds enable prey to use their maximum manoeuvring capacity and favour prey survival, and that the predator needs to be more athletic than its prey to sustain a viable success rate.

more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature Sustainability: Trade and the equitability of global food nutrient distribution

Nature Sustainability: Trade and the equitability of global food nutrient distribution | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
ABSTRACT: Access to sufficient, nutritious food is a basic human right and is necessary to achieving the United Nations’ Sustainable Development Goals. We demonstrate that international food trade, in the current global system, is essential to nutrient access and enables some poorer countries to be able to nourish up to hundreds of millions of people. Protectionist trade policies could therefore have serious negative consequences for food security.

more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: The lost art of looking at plants

Nature: The lost art of looking at plants | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
Advances in genomics and imaging are reviving a fading discipline.
fundoshi's insight:
来世はずっと顕微鏡みてる人生にしたい
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature News: Homing in on a key factor of climate change

Nature News: Homing in on a key factor of climate change | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

The quantity known as equilibrium climate sensitivity is crucial for understanding Earth’s future temperature1, and ongoing uncertainty about its value makes it harder to adequately prepare for the long-term effects of climate change2. This key parameter enumerates the increase in Earth’s average surface temperature that would occur if atmospheric carbon dioxide concentrations were doubled and the climate system was given enough time to reach an equilibrium state. More than 150 estimates of equilibrium climate sensitivity (ECS) have been published3, many of which suggest that worryingly high sensitivities are possible — including one that was published in Nature just a few weeks ago4. On page 319, Cox et al.5 use an ingenious approach to rule out high estimates. If correct, this would improve the chances of achieving internationally agreed targets for minimizing global warming.

more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs

Nature: Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: Maniraptora includes birds and their closest relatives among theropod dinosaurs. During the Cretaceous period, several maniraptoran lineages diverged from the ancestral coelurosaurian bauplan and evolved novel ecomorphologies, including active flight2, gigantism, cursoriality and herbivory. Propagation X-ray phase-contrast synchrotron microtomography of a well-preserved maniraptoran from Mongolia, still partially embedded in the rock matrix, revealed a mosaic of features, most of them absent among non-avian maniraptorans but shared by reptilian and avian groups with aquatic or semiaquatic ecologies. This new theropod, Halszkaraptor escuilliei gen. et sp. nov., is related to other enigmatic Late Cretaceous maniraptorans from Mongolia in a novel clade at the root of Dromaeosauridae. This lineage adds an amphibious ecomorphology to those evolved by maniraptorans: it acquired a predatory mode that relied mainly on neck hyperelongation for food procurement, it coupled the obligatory bipedalism of theropods with forelimb proportions that may support a swimming function, and it developed postural adaptations convergent with short-tailed birds.

fundoshi's insight:
かもかわいい
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Genetic diversity of the African malaria vector Anopheles gambiae

ABSTRACT: The sustainability of malaria control in Africa is threatened by the rise of insecticide resistance in Anopheles mosquitoes, which transmit the disease1. To gain a deeper understanding of how mosquito populations are evolving, here we sequenced the genomes of 765 specimens of Anopheles gambiae and Anopheles coluzzii sampled from 15 locations across Africa, and identified over 50 million single nucleotide polymorphisms within the accessible genome. These data revealed complex population structure and patterns of gene flow, with evidence of ancient expansions, recent bottlenecks, and local variation in effective population size. Strong signals of recent selection were observed in insecticide-resistance genes, with several sweeps spreading over large geographical distances and between species. The design of new tools for mosquito control using gene-drive systems will need to take account of high levels of genetic diversity in natural mosquito populations.

more...
No comment yet.
Rescooped by fundoshi from Adaptive Evolution and Speciation
Scoop.it!

Synima: a Synteny imaging tool for annotated genome assemblies - BMC Bioinformatics

Synima: a Synteny imaging tool for annotated genome assemblies - BMC Bioinformatics | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

Background
Ortholog prediction and synteny visualization across whole genomes are valuable methods for detecting and representing a range of evolutionary processes such as genome expansion, chromosomal rearrangement, and chromosomal translocation. Few standalone methods are currently available to visualize synteny across any number of annotated genomes.

Results
Here, I present a Synteny Imaging tool (Synima) written in Perl, which uses the graphical features of R. Synima takes orthologues computed from reciprocal best BLAST hits or OrthoMCL, and DAGchainer, and outputs an overview of genome-wide synteny in PDF. Each of these programs are included with the Synima package, and a pipeline for their use. Synima has a range of graphical parameters including size, colours, order, and labels, which are specified in a config file generated by the first run of Synima – and can be subsequently edited. Synima runs quickly on a command line to generate informative and publication quality figures. Synima is open source and freely available from https://github.com/rhysf/Synima under the MIT License.

Conclusions
Synima should be a valuable tool for visualizing synteny between two or more annotated genome assemblies.


Via Ronny Kellner
more...
Scooped by fundoshi
Scoop.it!

Nature: A semi-synthetic organism that stores and retrieves increased genetic information

Nature: A semi-synthetic organism that stores and retrieves increased genetic information | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: Since at least the last common ancestor of all life on Earth, genetic information has been stored in a four-letter alphabet that is propagated and retrieved by the formation of two base pairs. The central goal of synthetic biology is to create new life forms and functions1, and the most general route to this goal is the creation of semi-synthetic organisms whose DNA harbours two additional letters that form a third, unnatural base pair. Previous efforts to generate such semi-synthetic organisms2 culminated in the creation of a strain of Escherichia coli that, by virtue of a nucleoside triphosphate transporter from Phaeodactylum tricornutum, imports the requisite unnatural triphosphates from its medium and then uses them to replicate a plasmid containing the unnatural base pair dNaM–dTPT3. Although the semi-synthetic organism stores increased information when compared to natural organisms, retrieval of the information requires in vivo transcription of the unnatural base pair into mRNA and tRNA, aminoacylation of the tRNA with a non-canonical amino acid, and efficient participation of the unnatural base pair in decoding at the ribosome. Here we report the in vivo transcription of DNA containing dNaM and dTPT3 into mRNAs with two different unnatural codons and tRNAs with cognate unnatural anticodons, and their efficient decoding at the ribosome to direct the site-specific incorporation of natural or non-canonical amino acids into superfolder green fluorescent protein. The results demonstrate that interactions other than hydrogen bonding can contribute to every step of information storage and retrieval. The resulting semi-synthetic organism both encodes and retrieves increased information and should serve as a platform for the creation of new life forms and functions.r

fundoshi's insight:
わくわく
more...
No comment yet.
Rescooped by fundoshi from Plant-Microbe Symbiosis
Scoop.it!

Diverse peptide hormones affecting root growth identified in the Medicago truncatula secreted peptidome

Multigene families encoding diverse secreted peptide hormones play important roles in plant development. A need exists to efficiently elucidate the structures and post-translational modifications of these difficult-to-isolate peptide hormones in planta so that their biological functions can be determined. A mass spectrometry and bioinformatics approach was developed to comprehensively analyse the secreted peptidome of Medicago hairy root cultures and xylem sap. We identified 759 spectra corresponding to the secreted products of twelve peptide hormones including four CEP (C-TERMINALLY ENCODED PEPTIDE), two CLE (CLV3/ENDOSPERM SURROUNDING REGION RELATED) and six XAP (XYLEM SAP ASSOCIATED PEPTIDE) peptides. The MtCEP1, MtCEP2, MtCEP5 and MtCEP8 peptides identified differed in post-translational-modifications. Most were hydroxylated at conserved proline residues but some MtCEP1 derivatives were triarabinosylated. In addition, many CEP peptides possessed unexpected N- and C-terminal extensions. The pattern of these extensions suggested roles for endo- and exoproteases in CEP peptide maturation. Longer than expected, hydroxylated and homogeneously modified mono- and tri-arabinosylated CEP peptides corresponding to their in vivo structures were chemically synthesised to probe the effect of these post-translational-modifications on function. The ability of CEP peptides to elevate root nodule number was increased by hydroxylation at key positions. MtCEP1 peptides with N-terminal extensions or with triarabinosylation modification, however, were unable to impart increased nodulation. The MtCLE5 and MtCLE17 peptides identified were of precise size, and inhibited main root growth and increased lateral root number. Six XAP peptides, each beginning with a conserved DY sulfation motif, were identified including MtXAP1a, MtXAP1b, MtXAP1c, MtXAP3, MtXAP5 and MtXAP7. MtXAP1a and MtXAP5 inhibited lateral root emergence. Transcriptional analyses demonstrated peptide hormone gene expression in the root vasculature and tip. Since hairy roots can be induced on many plants, their corresponding root cultures may represent ideal source materials to efficiently identify diverse peptide hormones in vivo in a broad range of species.


Via Jean-Michel Ané
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nat Comm: Evolution of drift robustness in small populations

Nat Comm: Evolution of drift robustness in small populations | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
ABSTRACT: Most mutations are deleterious and cause a reduction in population fitness known as the mutational load. In small populations, weakened selection against slightly-deleterious mutations results in an additional fitness reduction. Many studies have established that populations can evolve a reduced mutational load by evolving mutational robustness, but it is uncertain whether small populations can evolve a reduced susceptibility to drift-related fitness declines. Here, using mathematical modeling and digital experimental evolution, we show that small populations do evolve a reduced vulnerability to drift, or ‘drift robustness’. We find that, compared to genotypes from large populations, genotypes from small populations have a decreased likelihood of small-effect deleterious mutations, thus causing small-population genotypes to be drift-robust. We further show that drift robustness is not adaptive, but instead arises because small populations can only maintain fitness on drift-robust fitness peaks. These results have implications for genome evolution in organisms with small effective population sizes.
more...
No comment yet.
Rescooped by fundoshi from Transport in plants and fungi
Scoop.it!

Gibberellin Localization and Transport in Plants

Gibberellin Localization and Transport in Plants | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
Distribution patterns and finely-tuned concentration gradients of plant hormones govern plant growth and development. Gibberellin (GA) is a plant hormone regulating key processes in plants; many of them are of significant agricultural importance, such as seed germination, root and shoot elongation, flowering, and fruit patterning. Although studies have demonstrated that GA movement is essential for multiple developmental aspects, how GAs are transported throughout the plant and where exactly they accumulate remain largely unknown. Here, we summarize recent findings from studies of GA movement and localization, and discuss the importance of GA intermediates in long- and short-distance movement. We further review recently identified Arabidopsis GA transporters and highlight their complex specialization and robust functional redundancy in GA transport activity.
 

Via Kevin Garcia
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Tailed giant Tupanvirus possesses the most complete translational apparatus of the known virosphere

Nature: Tailed giant Tupanvirus possesses the most complete translational apparatus of the known virosphere | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
Empty description
fundoshi's insight:
きもかわいい類
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature news: Debate blooms over anatomy of the world’s first flower

Nature news: Debate blooms over anatomy of the world’s first flower | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
 An ambitious effort to reconstruct the world’s first flower has seeded a debate over what forms a blossom can and cannot take. The project, called eFLOWER, combined an unparalleled database of plant traits, reams of molecular data on evolutionary relationships, and complex statistical models to determine what the ancestor of all modern flowering plants might have looked like. When its results were published last August1, they drew intense interest from academics and the media. But since then, researchers have raised questions about some of eFLOWER’s predictions. On 31 January, plant morphologist Dmitry Sokoloff of Moscow State University and his colleagues published a reanalysis of the data that suggests a different arrangement of key female reproductive structures in the first flower.


more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Evolutionary history of the angiosperm flora of China

Nature: Evolutionary history of the angiosperm flora of China | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: High species diversity may result from recent rapid speciation in a ‘cradle’ and/or the gradual accumulation and preservation of species over time in a ‘museum’1,2. China harbours nearly 10% of angiosperm species worldwide and has long been considered as both a museum, owing to the presence of many species with hypothesized ancient origins3,4, and a cradle, as many lineages have originated as recent topographic changes and climatic shifts—such as the formation of the Qinghai–Tibetan Plateau and the development of the monsoon—provided new habitats that promoted remarkable radiation5. However, no detailed phylogenetic study has addressed when and how the major components of the Chinese angiosperm flora assembled to form the present-day vegetation. Here we investigate the spatio-temporal divergence patterns of the Chinese flora using a dated phylogeny of 92% of the angiosperm genera for the region, a nearly complete species-level tree comprising 26,978 species and detailed spatial distribution data. We found that 66% of the angiosperm genera in China did not originate until early in the Miocene epoch (23 million years ago (Mya)). The flora of eastern China bears a signature of older divergence (mean divergence times of 22.04–25.39 Mya), phylogenetic overdispersion (spatial co-occurrence of distant relatives) and higher phylogenetic diversity. In western China, the flora shows more recent divergence (mean divergence times of 15.29–18.86 Mya), pronounced phylogenetic clustering (co-occurrence of close relatives) and lower phylogenetic diversity. Analyses of species-level phylogenetic diversity using simulated branch lengths yielded results similar to genus-level patterns. Our analyses indicate that eastern China represents a floristic museum, and western China an evolutionary cradle, for herbaceous genera; eastern China has served as both a museum and a cradle for woody genera. These results identify areas of high species richness and phylogenetic diversity, and provide a foundation on which to build conservation efforts in China.

fundoshi's insight:
中国2300万年の歴史。
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nat Plants: Speed breeding is a powerful tool to accelerate crop research and breeding

Nat Plants: Speed breeding is a powerful tool to accelerate crop research and breeding | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: The growing human population and a changing environment have raised significant concern for global food security, with the current improvement rate of several important crops inadequate to meet future demand1. This slow improvement rate is attributed partly to the long generation times of crop plants. Here, we present a method called ‘speed breeding’, which greatly shortens generation time and accelerates breeding and research programmes. Speed breeding can be used to achieve up to 6 generations per year for spring wheat (Triticum aestivum), durum wheat (T. durum), barley (Hordeum vulgare), chickpea (Cicer arietinum) and pea (Pisum sativum), and 4 generations for canola (Brassica napus), instead of 2–3 under normal glasshouse conditions. We demonstrate that speed breeding in fully enclosed, controlled-environment growth chambers can accelerate plant development for research purposes, including phenotyping of adult plant traits, mutant studies and transformation. The use of supplemental lighting in a glasshouse environment allows rapid generation cycling through single seed descent (SSD) and potential for adaptation to larger-scale crop improvement programs. Cost saving through light-emitting diode (LED) supplemental lighting is also outlined. We envisage great potential for integrating speed breeding with other modern crop breeding technologies, including high-throughput genotyping, genome editing and genomic selection, accelerating the rate of crop improvement.

fundoshi's insight:
Fig1bが難解ですがおもしろいです
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Pathogens boosted by food additive

Nature: Pathogens boosted by food additive | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
Between 2001 and 2006, epidemic strains of the bacterium Clostridium difficile, which can inhabit the bowel and cause dangerous diarrhoea, unexpectedly emerged in the United States, Canada and several European countries1,2. Most of these strains originated from a single lineage of C. difficile known as ribotype 027 (RT0272), which has now spread around the world3. Of particular concern has been the correlation between RT027 and a dramatic increase in deaths related to C. difficile4. The mystery of why this ribotype and a second one, RT078, became so prevalent apparently out of thin air has remained largely unsolved5. On page 291, Collins et al.6 raise the possibility that the seemingly harmless addition of a sugar called trehalose to the food supply contributed to this disease epidemic.
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nat Human Behavior: Population structured by witchcraft beliefs

Nat Human Behavior: Population structured by witchcraft beliefs | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: Anthropologists have long argued that fear of victimization through witchcraft accusations promotes cooperation in small-scale societies1. Others have argued that witchcraft beliefs undermine trust and therefore reduce social cohesion2. However, there are very few, if any, quantified empirical examples demonstrating how witchcraft labels can structure cooperation in real human communities. Here we show a case from a farming community in China where people labelled zhu were thought capable of supernatural activity, particularly poisoning food. The label was usually applied to adult women heads of household and often inherited down the female line. We found that those in zhu households were less likely to give or receive gifts or farm help to or from non-zhu households; nor did they have sexual partnerships or children with those in non-zhu households. However, those in zhu households did preferentially help and reproduce with each other. Although the tag is common knowledge to other villagers and used in cooperative and reproductive partner choice, we found no evidence that this assortment was based on cooperativeness or quality. We favour the explanation that stigmatization originally arose as a mechanism to harm female competitors. Once established, fear that the trait is transmissible may help explain the persistence of this deep-rooted cultural belief.

more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Sci Rep: Self-righting potential and the evolution of shell shape in Galápagos tortoises

Sci Rep: Self-righting potential and the evolution of shell shape in Galápagos tortoises | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT: Self-righting, the capacity of an animal to self-turn after falling on its back, is a fitness-related trait. Delayed self-righting can result in loss of mating opportunities or death. Traits involved in self-righting may therefore be under selection. Galápagos giant tortoises have two main shell morphologies - saddleback and domed – that have been proposed to be adaptive. The more sloped shape on the sides of the shell and the longer extension of neck and legs of the saddlebacks could have evolved to optimize self-righting. The drier environments with more uneven surfaces where the saddleback tortoises occur increases their risk to fall on their back while walking. The ability to fast overturn could reduce the danger of dying. To test this hypothesis, we used 3D shell reconstructions of 89 Galápagos giant tortoises from three domed and two saddleback species to compare self-righting potential of the two shell morphotypes. Our results indicate that saddleback shells require higher energy input to self-right than domed ones. This suggests that several traits associated with the saddleback shell morphology could have evolved to facilitate self-righting. Studying the functional performances of fitness-related traits, as in this work, could provide important insight into the adaptive value of traits.

fundoshi's insight:
来世でこういうことやりたい
more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Nature: Reconciling taxon senescence with the Red Queen’s hypothesis

Nature: Reconciling taxon senescence with the Red Queen’s hypothesis | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it

ABSTRACT:In the fossil record, taxa exhibit a regular pattern of waxing and waning of occupancy, range or diversity between their origin and extinction. This pattern appears to contradict the law of constant extinction1, which states that the probability of extinction in a given taxon is independent of that taxon’s age. It is nevertheless well established for species, genera and higher taxa of terrestrial mammals2,3,4, marine invertebrates5,6,7, marine microorganisms8, and recent Hawaiian clades of animals and plants9. Here we show that the apparent contradiction between a stochastically constant extinction rate and the seemingly deterministic waxing and waning pattern of taxa disappears when we consider their peak of expansion rather than their final extinction. To a first approximation, we find that biotic drivers of evolution pertain mainly to the peak of taxon expansion, whereas abiotic drivers mainly apply to taxon extinction. The Red Queen’s hypothesis1, which emphasizes biotic interactions, was originally proposed as an explanation of the law of constant extinction. Much effort has since been devoted to determining how this hypothesis, emphasizing competition for resources, relates to the effects of environmental change. One proposed resolution is that biotic and abiotic processes operate at different scales10. By focusing attention on taxon expansion rather than survival, we resolve an apparent contradiction between the seemingly deterministic waxing and waning patterns over time and the randomness of extinction that the Red Queen’s hypothesis implies.

fundoshi's insight:
more...
No comment yet.
Rescooped by fundoshi from Plant Immunity And Microbial Effectors
Scoop.it!

Exchanging missives and missiles: the roles of extracellular vesicles in plant–pathogen interactions | Journal of Experimental Botany | Oxford Academic

Exchanging missives and missiles: the roles of extracellular vesicles in plant–pathogen interactions | Journal of Experimental Botany | Oxford Academic | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
This article comments on:Regente M, Pinedo M, San Clemente H, Balliau T, Jamet E, de la Canal L. 2017. Plant extracellular vesicles are incorporated by a fungal

Via IPM Lab
more...
Bridget Barker's curator insight, November 30, 2017 11:12 AM
Curious about EVs in human fungal pathogens...
Scooped by fundoshi
Scoop.it!

Sci Rep: Radiographic assessment of the skeletons of Dolly and other clones finds no abnormal osteoarthritis

ABSTRACT: Our recent report detailing the health status of cloned sheep concluded that the animals had aged normally. This is in stark contrast to reports on Dolly (first animal cloned from adult cells) whose diagnoses of osteoarthritis (OA) at 5½ years of age led to considerable scientific concern and media debate over the possibility of early-onset age-related diseases in cloned animals. Our study included four 8-year old ewes derived from the cell line that gave rise to Dolly, yet none of our aged sheep showed clinical signs of OA, and they had radiographic evidence of only mild or, in one case, moderate OA. Given that the only formal record of OA in Dolly is a brief mention of a single joint in a conference abstract, this led us to question whether the original concerns about Dolly’s OA were justified. As none of the original clinical or radiographic records were preserved, we undertook radiographic examination of the skeletons of Dolly and her contemporary clones. We report a prevalence and distribution of radiographic-OA similar to that observed in naturally conceived sheep, and our healthy aged cloned sheep. We conclude that the original concerns that cloning had caused early-onset OA in Dolly were unfounded.

more...
No comment yet.
Scooped by fundoshi
Scoop.it!

Genetic Components of Root Architecture Remodeling in Response to Salt Stress

Genetic Components of Root Architecture Remodeling in Response to Salt Stress | fundoshi TOPICS: Plant biology, cell biology, and more | Scoop.it
Salinity of the soil is highly detrimental to plant growth. Plants respond by a redistribution of root mass between main and lateral roots, yet the genetic machinery underlying this process is still largely unknown. Here, we describe the natural variation among 347 Arabidopsis thaliana accessions in root system architecture (RSA) and identify the traits with highest natural variation in their response to salt. Salt-induced changes in RSA were associated with 100 genetic loci using genome-wide association studies (GWAS). Two candidate loci associated with lateral root development were validated and further investigated. Changes in CYP79B2 expression in salt stress positively correlated with lateral root development in accessions, and cyp79b2 cyp79b3 double mutants developed fewer and shorter lateral roots under salt stress, but not in control conditions. By contrast, high HKT1 expression in the root repressed lateral root development, which could be partially rescued by addition of potassium. The collected data and Multi-Variate analysis of multiple RSA traits, available through the Salt\_NV\_Root App, capture root responses to salinity. Together, our results provide a better understanding of effective RSA remodeling responses, and the genetic components involved, for plant performance in stress conditions.
more...
No comment yet.