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Comparative Transcriptome Analysis Shows Conserved Metabolic Regulation during Production of Secondary Metabolites in Filamentous Fungi.
No full textSecondary metabolites are a major source of pharmaceuticals, especially antibiotics. However, the development of efficient processes of production of secondary metabolites has proved troublesome due to a limited understanding of the metabolic regulations governing secondary metabolism. By analyzing the conservation in gene expression across secondary metabolite-producing fungal species, we identified a metabolic signature that links primary and secondary metabolism and that demonstrates that fungal metabolism is tailored for the efficient production of secondary metabolites. The insight that we provide can be used to develop high-yielding fungal cell factories that are optimized for the production of specific secondary metabolites of pharmaceutical interest
Expanding the frontier in education research: Teacher education could help promote activities that affect students' ability to learn in the long-run
No full textThe very name of this journal, Frontiers in Education, begs the questions of where the “frontiers” should be at present in education research, and how we can ensure that breakthroughs at these frontiers be rapidly put into practice. In this context, this short opinion article argues that in order to answer these two questions adequately, we, educators, should stop zeroing in on the content or skills we want students to have acquired right at the end of a cycle of studies, be it elementary, high school, or university. Instead, we should not be afraid to ask people who are many years, even decades, past formal education what they think we should focus on, where our teaching can be most effective. My own experience with two eye-opening events suggests that from this lifelong perspective, teaching activities that are likely to be most influential over the course of a person’s life do not necessarily follow traditional formats. In terms of facilitating implementation of innovative teaching activities, since it seems very arduous to convince schools to add anything to already overloaded curricula, perhaps this is not where we should concentrate our efforts. I argue that the easiest way to implement changemay be to first demonstrate practically to future teachers, enrolled in teacher education programs, that even brief learning activities can have enormous merit
Flower bud proteome reveals modulation of sex-biased proteins potentially associated with sex expression and modification in dioecious Coccinia grandis.
No full textDioecy is an important sexual system wherein, male and female flowers are borne on separate unisexual plants. Knowledge of sex-related differences can enhance our understanding in molecular and developmental processes leading to unisexual flower development. Coccinia grandis is a dioecious species belonging to Cucurbitaceae, a family well-known for diverse sexual forms. Male and female plants have 22A + XY and 22A + XX chromosomes, respectively. Previously, we have reported a gynomonoecious form (22A + XX) of C. grandis bearing morphologically hermaphrodite flowers (GyM-H) and female flowers (GyM-F). Also, we have showed that foliar spray of AgNO3 on female plant induces morphologically hermaphrodite bud development (Ag-H) despite the absence of Y-chromosome
Phytosanitary protocols and constraints relating to apple exports - comparison of three major exporting countries: France, Italy and Chile
No full textThe Sustain'Apple project deals with phytosanitary regulations in international trade and the institutional devices to comply with those regulations. Phytosanitary regulations are issued by new destination countries (mostly in Asia and North and South America) to avoid importing and disseminating quarantine organisms (in particular pests) and limit the economic effects of regulated non-quarantine organisms. Our report focuses on public and private devices which formulate, negotiate and implement the phytosanitary protocols that exporting countries must comply with, to get access to targeted markets. By comparing France with Italy and Chile, we have been able to identify strengths and weaknesses of the French system. The interest for such a comparison arouses from the two following questions : first how can we explain the contrasted market positioning between France and Italy on one hand and Chile on the other hand, Chile having by far the largest market share in destinations with phytosanitary constraints; second, how can we explain low institutional efficacy in preparing and negotiating phytosanitary protocols as revealed by professional leaders who regret lack of information from and weak cooperation with plant protection services. The institutional devices comparison has been conducted after having positioned the markets of the three countries and identified, for each of them, issues of quarantine pests and phytosanitary constraints imposed by main customer countries
A functional biogeography approach to insular bird communities with mixed-origin species
No full textSpecies introductions on islands result into heterogeneous assemblages with short common biogeo-
graphic histories, yet potentially redundant ecological functions. How native and feral species
interact over resource and habitat in the absence of long co-evolutionary histories presides to the
deterministic part of assembly processes in these assemblages, in turn affecting strategies to
preserve indigenous bio- diversity. Critical to this question are the ability of introduced species
to cope with novel environments and their degree of niche separation with native species, which may
or not permit local invasion. These processes can be investigated by studying shifts in alien
species’ ecological trait space between their native and introduction ranges, and its degree of
overlap with co-occuring native species on introduction grounds, accounting for the depth of their
common phylogenetic histories. Previous results suggested that insular assemblages are driven
either by past competitive exclusion, habitat filtering or niche dis- placement associated with
post-introduction lability in species’ trait space. We attempt to disentangle these processes in
New Zealand bird assemblages, which uniquely mix species from multiple biogeo- graphical origin and
range from narrow endemism to colonizing alien birds. New Zealand thus hosts some of the world’s
most peculiar bird assemblages, albeit without obvious conflicts among species with differing local
histories. We use a multispecies hierarchical bayesian model fitted on 501 point counts to
investigate niche separation between 21 alien and native species through their responses in abun-
dance to habitat composition at landscape (proportion of native and man-modified habitats) and
local scales (forest composition and vertical structure). Complementarily, we investigate the roles
of species’ ecological trait space and biogeographical origins in these responses through an
ordination framework constructed with literature data. Our results support habitat filtering
operating simultaneously at multiple scales, associated with trait-based separation between native
and alien species. We further present preliminary results on the contributions of biogeographic
origin and phylogenetic relatedness to habitat-trait associations in New-Zealand bird assemblages,
and eventually propose avenues to refine these results through novel curve analysis methods. Our
framework aims to integrates functional and biogeographic perspectives on novel insular communities
to the benefit of a better understanding and conservation of island biodiversity
The Needs for Developing Experiments on Reservoirs in Hantavirus Research: Accomplishments, Challenges and Promises for the Future
No full textDue to their large geographic distribution and potential high mortality rates in human infections, hantaviruses constitute a worldwide threat to public health. As such, they have been the subject of a large array of clinical, virological and eco-evolutionary studies. Many experiments have been conducted in vitro or on animal models to identify the mechanisms leading to pathogenesis in humans and to develop treatments of hantavirus diseases. Experimental research has also been dedicated to the understanding of the relationship between hantaviruses and their reservoirs. However, these studies remain too scarce considering the diversity of hantavirus/reservoir pairs identified, and the wide range of issues that need to be addressed. In this review, we present a synthesis of the experimental studies that have been conducted on hantaviruses and their reservoirs. We aim at summarizing the knowledge gathered from this research, and to emphasize the gaps that need to be filled. Despite the many di_culties encountered to carry hantavirus experiments, we advocate for the need of such studies in the future, at the interface of evolutionary ecology and virology. They are critical to address emerging areas of research, including hantavirus evolution and the epidemiological consequences of individual variation in infection outcomes
Microbial genes for a circular and sustainable Bio-PET Economy.
No full textPlastics have become an important environmental concern due to their durability and resistance to degradation. Out of all plastic materials, polyesters such as polyethylene terephthalate (PET) are amenable to biological degradation due to the action of microbial polyester hydrolases. The hydrolysis products obtained from PET can thereby be used for the synthesis of novel PET as well as become a potential carbon source for microorganisms. In addition, microorganisms and biomass can be used for the synthesis of the constituent monomers of PET from renewable sources. The combination of both biodegradation and biosynthesis would enable a completely circular bio-PET economy beyond the conventional recycling processes. Circular strategies like this could contribute to significantly decreasing the environmental impact of our dependence on this polymer. Here we review the efforts made towards turning PET into a viable feedstock for microbial transformations. We highlight current bottlenecks in degradation of the polymer and metabolism of the monomers, and we showcase fully biological or semisynthetic processes leading to the synthesis of PET from sustainable substrates
Active thrombin produced by the intestinal epithelium controls mucosal biofilms
No full textProteolytic homeostasis is important at mucosal surfaces, but its actors and their precise role in physiology are poorly understood. Here we report that healthy human and mouse colon epithelia are a major source of active thrombin. We show that mucosal thrombin is directly regulated by the presence of commensal microbiota. Specific inhibition of luminal thrombin activity causes macroscopic and microscopic damage as well as transcriptomic alterations of genes involved in host-microbiota interactions. Further, luminal thrombin inhibition impairs the spatial segregation of microbiota biofilms, allowing bacteria to invade the mucus layer and to translocate across the epithelium. Thrombin cleaves the biofilm matrix of reconstituted mucosa-associated human microbiota. Our results indicate that thrombin constrains biofilms at the intestinal mucosa. Further work is needed to test whether thrombin plays similar roles in other mucosal surfaces, given that lung, bladder and skin epithelia also express thrombin
Classification of Crops, Pastures, and Tree Plantations along the Season with Multi-Sensor Image Time Series in a Subtropical Agricultural Region
No full textTimely and efficient land-cover mapping is of high interest, especially in agricultural landscapes. Classification based on satellite images over the season, while important for cropland monitoring, remains challenging in subtropical agricultural areas due to the high diversity of management systems and seasonal cloud cover variations. This work presents supervised object-based classifications over the year at 2-month time-steps in a heterogeneous region of 12,000 km(2) in the Sao Paulo region of Brazil. Different methods and remote-sensing datasets were tested with the random forest algorithm, including optical and radar data, time series of images, and cloud gap-filling methods. The final selected method demonstrated an overall accuracy of approximately 0.84, which was stable throughout the year, at the more detailed level of classification; confusion mainly occurred among annual crop classes and soil classes. We showed in this study that the use of time series was useful in this context, mainly by including a small number of highly discriminant images. Such important images were eventually distant in time from the prediction date, and they corresponded to a high-quality image with low cloud cover. Consequently, the final classification accuracy was not sensitive to the cloud gap-filling method, and simple median gap-filling or linear interpolations with time were sufficient. Sentinel-1 images did not improve the classification results in this context. For within-season dynamic classes, such as annual crops, which were more difficult to classify, field measurement efforts should be densified and planned during the most discriminant window, which may not occur during the crop vegetation peak