Actualités 2019

Axons, the threadlike part of a nerve cell that conducts impulses, are both flexible and strong, which makes them a mystery in the eyes of biologists. Recent studies have shown that under the axonal membrane, rings composed of actin filaments give the structure its flexibility. But those studies had not been able to define the precise architecture of these rings.

Since 2013, a European Union (EU) moratorium has restricted the application of three neonicotinoids to crops that attract bees because of the harmful effects they are deemed to have on these insects. Yet researchers from the CNRS, INRA, and the Institut de l'Abeille (ITSAP) have just demonstrated that residues of these insecticides-and especially of imidacloprid-can still be detected in rape nectar from 48% of the plots of studied fields, their concentrations varying greatly over the years.

In a multicellular organism, gene expression regulation allows cells to live, divide and ensure their proper physiological role. The molecular nature of this process (e.g. low molecule number, Brownian movements..) involves random variations. Indeed, with the same genetic background, two neighbor cells do not express their genes in the same way.

Publication by IGFL on October 22, 2019. Drosophila larvae spend most of their short lives gorging on rotting fruit. In their 'spare time' these intriguing animals also display phases of intense physical exercise. They are capable of an astonishing array of complex locomotor behaviours such as crawling at different speeds, crawling backwards, performing sharp turns, head sweeps and pauses.

Natural transformation (i.e., the uptake of DNA and its stable integration in the chromosome) is a major mechanism of horizontal gene transfer in bacteria. Although the vast majority of bacterial genomes carry the genes involved in natural transformation, close relatives of naturally transformable species often appear not competent for natural transformation.

Publication by Laboratoire de géologie de Lyon in Scientific Reports on October 17, 2019. Communication from CNRS info. Though our understanding of the anatomy of the earliest animals is growing ever more precise, we know next to nothing about their behaviour. Did group behaviour arise recently or is it primeval?

For more than a century, the Nissle 1917 strain of the bacterium Escherichia coli has been used as a probiotic to treat gastrointestinal disorders. However, this bacterium also produces a toxin, colibactin, which has deleterious effects on host DNA and might cause colon cancer. It is therefore crucial to understand the mechanisms at play in the strain if we wish to limit undesirable side effects.

An international team * led by researchers from INRA and CEA managed to assemble the first sequence of the pea genome. This study, published on September 2, 2019 , will, in addition to increasing knowledge of this genome compared to that of other legumes, help to improve traits of interest for peas, such as disease resistance, regularity of yield and nutritional value.

Scientists from INRA, CEA, CNRS, CNES and several international universities 1 have quantified - over the 2010-2017 period ' the time changes in the carbon stocks of aboveground vegetation biomass in the tropics. One main result is that over the studied time period, these stocks are almost constant: gains in biomass carbon stocks in some regions of the tropics are compensated by losses due to deforestation or diebacks linked to climate impacts (in particular the El Niño events).

INRA researchers, in collaboration with the University of Adelaide, Australia, studied the effects that a widely used artificial sweetener blend, i.e. acesulfame K-sucralose, has on metabolism. For the first time, they revealed ' in animals ' an increase in glucose absorption, particularly in the brain and fatty tissues, indicating certain undesirable effects on metabolism and insulin sensitivity.

The demo enables massively parallel, low-power and low-latency computation abd will be demonstrated at Flash Memory Summit 2019, August 6-8. Weebit Nano (ASX: WBT), the Israel-based semiconductor company seeking to develop and commercialize the next generation of memory technology, and CEA-Leti, a global leader in miniaturization technologies enabling smart, energy-efficient and secure solutions for industry, will demonstrate a new neuromorphic demo able to perform precise object recognition tasks in an energy-efficient manner at Flash Memory Summit 2019.

Prebiotics are currently a preferred treatment for certain metabolic disorders, as they can restore the balance of dysfunctional gut microbiota, and improve the body's metabolism. However, these substances have to be used at high doses, which can result in patients experiencing bloating and flatulence.

Which grape varieties were popular for making wine in ancient times' Do they resemble those in use today? An international consortium which included INRA, the CNRS and the University of Montpellier1 has shed new light on viticulture in ancient Rome and the Middle Ages. Researchers sequenced the DNA of 28 grape seeds found on archaeological sites in France and compared their genomes to those of modern grape varieties.

Researchers at INRA, ANSES, and ENVA have discovered that bluetongue virus can enhance its replication by exploiting one of its host's cellular pathways. Published in the Journal of Virology , their results could help the quest to identify effective antiviral compounds for combating the virus. Bluetongue virus (BTV) can infect wild and domestic species of ruminants (ovines, caprines, and bovines).

How do you know if a seed is well suited to a given environment? How can you predict its yield for a particular climate? Farmers need to know the answers to these questions when choosing their seeds because yields depend on complex interactions between seed genotype and environmental conditions. Researchers at INRA and Wageningen University & Research (WUR, Netherlands) have developed a model to predict the yield of any maize hybrid based on its genes and environmental conditions.

One of the crucial stages of gestation is implantation of the embryo in the uterus, in contact with a tissue called the endometrium. However, the mechanisms that enable this implantation remain largely unclear. A Franco-American collaboration co-led by INRA research scientists has revealed that intense and fine-tuned crosstalk is established between the embryo and endometrium, allowing them to adapt to each other.

An international research team that included INRA and CNRS scientists has revealed the key role played by rare plant species in maintaining ecosystem "multifunctionality": both species and evolutionary diversity is important. This work was recently been published in PNAS . Based on data from 123 sampling sites around the world, the results show that taxonomic, functional, and phylogenetic biodiversity matters for ecosystem functioning.

INRA, CIRAD, and CNRS researchers recently made an unprecedented discovery: the different genomic segments of a multipartite 1 virus can occupy distinct cells within their host but still work together to generate infection. This finding challenges a key paradigm in virology, notably that a virus's entire genome must enter a given cell and replicate therein before repeating the process in subsequent cells, thus causing infection.

Researchers from INRA, CIRAD, CEA, the University of Montpellier, and Chicago and Vanderbilt Universities in the United States have developed an innovative method for analysing the genome of the Wolbachia bacterium. This endosymbiotic* bacterium infects more than 70% of insects and is capable of influencing insect transmission of pathogens such as dengue or Zika virus.

Research teams from the Villefranche-sur-Mer Developmental Biology Laboratory (jointly managed by Sorbonne University and CNRS), in collaboration with the Biological Institute Paris-Seine (Sorbonne University), CEA-Genoscope and the University of Vienna have decoded the genome of the jellyfish Clytia.