Comptes Rendus Biologies最新文献

Roger Guillemin discovered and characterized the hypothalamic factors that control anterior pituitary functions. He consequently demonstrated that these brain peptides regulate a large number of major body activities through neuroendocrine mechanisms. This especially include growth, fertility and reproduction, endocrine gland functions and stress. These seminal works paved the way to major applications in many fields of physiology and medicine for diagnosis, pharmacology and therapy, far beyond the initial discovery and properties of these molecules, including in cancerology, immunology, inflammation, drug addiction and behavior.

A large body of literature highlights the importance of energy metabolism in the response of haematological malignancies to therapy. In this review, we are particularly interested in acute myeloid leukaemia, where mitochondrial metabolism plays a key role in response and resistance to treatment. We describe the new concept of mitohormesis in the response to therapy-induced stress and in the initiation of relapse in this disease.

Fertility is declining worldwide and many couples are turning towards assisted reproductive technologies (ART) to conceive babies. Organisms that propagate via sexual reproduction often come from the fusion between two gametes, an oocyte and a sperm, whose qualities seem to be decreasing in the human species. Interestingly, while the sperm mostly transmits its haploid genome, the oocyte transmits not only its haploid set of chromosomes but also its huge cytoplasm to its progeny. This is what can be defined as the maternal inheritance composed of chromosomes, organelles, lipids, metabolites, proteins and RNAs. To decipher the decline in oocyte quality, it is essential to explore the nature of the maternal inheritance, and therefore study the last stages of murine oogenesis, namely the end of oocyte growth followed by the two meiotic divisions. These divisions are extremely asymmetric in terms of the size of the daughter cells, allowing to preserve the maternal inheritance accumulated during oocyte growth within these huge cells to support early embryo development. Studies performed in Marie-Hélène Verlhac's lab have allowed to discover the unprecedented impact of original acto-myosin based mechanisms in the constitution as well as the preservation of this maternal inheritance and the consequences when these processes go awry.

In nature, plants defend themselves against pathogen attack by activating an arsenal of defense mechanisms. During the last decades, work mainly focused on the understanding of qualitative disease resistance mediated by a few genes conferring an almost complete resistance, while quantitative disease resistance (QDR) remains poorly understood despite the fact that it represents the predominant and more durable form of resistance in natural populations and crops. Here, we review our past and present work on the dissection of the complex mechanisms underlying QDR in Arabidopsis thaliana. The strategies, main steps and challenges of our studies related to one atypical QDR gene, RKS1 (Resistance related KinaSe 1), are presented. First, from genetic analyses by QTL (Quantitative Trait Locus) mapping and GWAs (Genome Wide Association studies), the identification, cloning and functional analysis of this gene have been used as a starting point for the exploration of the multiple and coordinated pathways acting together to mount the QDR response dependent on RKS1. Identification of RKS1 protein interactors and complexes was a first step, systems biology and reconstruction of protein networks were then used to decipher the molecular roadmap to the immune responses controlled by RKS1. Finally, exploration of the potential impact of key components of the RKS1-dependent gene network on leaf microbiota offers interesting and challenging perspectives to decipher how the plant immune systems interact with the microbial communities' systems.

History has remembered Joseph Banks as the explorer-botanist of the first voyage of James Cook. Yet, shortly after his return, he got elected president of the Royal Society and, for over 40 years, he then played in Great Britain an eminent role in reorganizing natural sciences and advocating an "economic botany". He actively intervened in acclimatization and varietal selection of plants and animals in Great Britain as in the future English colonies. Thus he built an intellectual environment which will promote the emergence of Charles Darwin's thoughts.

The fight against antibiotic resistance in the animal sector over the last ten years in France (Ecoantibio plans) has largely focused on reducing the veterinary use of antibiotics. However, antibiotic resistance in an animal is not necessarily due to antibiotic therapy, but can also result from the transmission of resistant bacteria or resistance plasmids. Several examples illustrate the importance of this transmission of antibiotic resistance in the animal world, which are detailed in this communication. Like in human medicine, this nosocomial transmission can be observed in veterinary care institutions, as well as in animal husbandry. It also explains the presence of antibiotic resistance on the surface of foodstuffs, which by definition are not treated with antibiotics. At the international level, countries that are very virtuous in their use of veterinary antibiotics can display high levels of antibiotic resistance through the importation of carrier animals. Finally, the presence of antibiotic resistance in wildlife is likewise explained by contamination and not by antibiotic treatment. All these situations demonstrate that, in addition to paying attention to antibiotic prescription, an equally important facet of the fight against antibiotic resistance is to control the transmission routes of resistant bacteria.