The CADM1 tumor suppressor gene is a major candidate gene in MDS with deletion of the long arm of chromosome 11.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis leading to peripheral cytopenias and in a substantial proportion of cases to acute myeloid leukemia. The deletion of the long arm of chromosome 11, del(11q), is a rare but recurrent clonal event in MDS. Here, we detail the largest series of 113 cases of MDS and myelodysplastic syndromes/myeloproliferative neoplasms (MDS/MPN) harboring a del(11q) analyzed at clinical, cytological, cytogenetic, and molecular levels. Female predominance, a survival prognosis similar to other MDS, a low monocyte count, and dysmegakaryopoiesis were the specific clinical and cytological features of del(11q) MDS. In most cases, del(11q) was isolated, primary and interstitial encompassing the 11q22-23 region containing ATM, KMT2A, and CBL genes. The common deleted region at 11q23.2 is centered on an intergenic region between CADM1 (also known as Tumor Suppressor in Lung Cancer 1) and NXPE2. CADM1 was expressed in all myeloid cells analyzed in contrast to NXPE2. At the functional level, the deletion of Cadm1 in murine Lineage-Sca1+Kit+ cells modifies the lymphoid-to-myeloid ratio in bone marrow, although not altering their multilineage hematopoietic reconstitution potential after syngenic transplantation. Together with the frequent simultaneous deletions of KMT2A, ATM, and CBL and mutations of ASXL1, SF3B1, and CBL, we show that CADM1 may be important in the physiopathology of the del(11q) MDS, extending its role as tumor-suppressor gene from solid tumors to hematopoietic malignancies

A high-throughput spectrophotometric assay of adult size in Drosophila that facilitates microbial and biochemical content analysis

International audienceLarge-scale laboratory experiments often necessitate the processing of numerous samples in little time, their long-time storage and the joint analysis of morphological, biochemical, and microbiological features. Combining different types of assays is often not compatible with classical methods to estimate size in adult Drosophila flies. We therefore designed a new spectrophotometric assay for the high-throughput estimation of adult size in Drosophila that facilitates microbial and biochemical content analysis. The new method uses optical density at 202 nm of single fly homogeneates as size proxy. We tested the method in a variety of Drosophila populations -including wild caught flies- and compared its explanatory power with two classical size estimates: wet-weight and wing-length. It was also used to control for size when comparing the fat content of different fly populations. Results show fly homogenate optical density is an powerful size proxy that may be used for both male and female flies

Influence of bacteria on the maintenance of a yeast during Drosophila melanogaster metamorphosis

International audienceInteractions between microorganisms associated with metazoan hosts are emerging as key features of symbiotic systems. Little is known about the role of such interactions on the maintenance of host-microorganism association throughout the host’s life cycle. We studied the influence of extracellular bacteria on the maintenance of a wild isolate of the yeast Saccharomyces cerevisiae through metamorphosis of the fly Drosophila melanogaster reared in fruit. Yeasts maintained through metamorphosis only when larvae were associated with extracellular bacteria isolated from D. melanogaster faeces. One of these isolates, an Enterobacteriaceae, favoured yeast maintenance during metamorphosis. Such bacterial influence on host-yeast association may have consequences for the ecology and evolution of insect-yeast-bacteria symbioses in the wild

Environmental specificity in Drosophila-bacteria symbiosis affects host developmental plasticity

Environmentally acquired microbial symbionts could contribute to host adaptation to local conditions like vertically transmitted symbionts do. This scenario necessitates symbionts to have different effects in different environments. We investigated this idea in Drosophila melanogaster, a species which communities of bacterial symbionts vary greatly among environments.We isolatedfour bacterial strains isolated from the feces of a D. melanogasterlaboratory strain and tested their effects in two conditions:the ancestral environment (i.e. the laboratory medium) and a new environment (i.e. fresh fruit with live yeast). All bacterial effects on larval and adult traits differed among environments, ranging from very beneficial to marginally deleterious. The joint analysis of larval development speed and adult size further shows bacteria affected developmental plasticity more than resource acquisition. This effect was largely driven by the contrasted effects of the bacteria in each environment. Our study illustrates that understanding D. melanogastersymbiotic interactions in the wild will necessitate working in ecologically realistic conditions. Besides, context-dependent effects of symbionts, and their influence on host developmental plasticity, shed light on howenvironmentally acquired symbionts may contribute to host evolution.Keywords:symbiosis; extracellular bacteria; Drosophila melanogaster; life history traits; developmentalplasticity; resource acquisitio

Microbial warfare between competing Drosophila species shapes niche partition

National audienceDeciphering the mechanisms of niche separation between species is a central question in ecology. However, the influence of symbiotic microbes on competitive interactions remains seldom studied. Microbe-mediated niche partitioning may be particularly important in Drosophilid flies, which larvae rely on exo-symbiotic microbes for fruit consumption. We previously demonstrated how the invasive pest Drosophila suzukii facilitates fruit infestation by D. melanogaster through the wounding of fruits by ovipositing females, and the subsequent cultivation of bacteria and yeast by offspring larvae. We now demonstrate that ovipositing D. suzukii females avoid fruits previously exposed to D. melanogaster. Using axenic strains, we further show that microbes carried by D. melanogaster are responsible for this repellency. Additional experiments reveal that the avoidance of D. melanogaster by D. suzukii relies on short-scale taste perception. Comparison among D. suzukii populations indicates the behavior is present in populations from both the native and invasive ranges but depends on previous fly experience. On-going experiments test the hypothesis that D. suzukii females avoid fruits infested by D. melanogaster because its symbionts would create conditions unfavorable for D. suzukii progeny. Our study highlights how symbiotic microbes may determine interspecific interactions and niche partitioning through facilitation and competition; the results further suggest natural repellents may provide innovative and sustainable biocontrol solutions against agricultural pest

Bacterial influence on the maintenance of symbiotic yeast through Drosophila metamorphosis

Interactions between microbial symbionts of metazoan hosts are emerging as key features of symbiotic systems. Little is known about the role of such interactions on the maintenance of symbiosis through host’s life cycle. We studied the influence of symbiotic bacteria on the maintenance of symbiotic yeast through metamorphosis of the fly Drosophila melanogaster . To this end we mimicked the development of larvae in natural fruit. In absence of bacteria yeast was never found in young adults. However, yeast could maintain through metamorphosis when larvae were inoculated with symbiotic bacteria isolated from D. melanogaster faeces. Furthermore, an Enterobacteriaceae favoured yeast transstadial maintenance. Because yeast is a critical symbiont of D. melanogaster flies, bacterial influence on host-yeast association may have consequences for the evolution of insect-yeast-bacteria tripartite symbiosis and their cooperation

Comparison between Pressurized Liquid Extraction and Conventional Soxhlet Extraction for Rosemary Antioxidants, Yield, Composition, and Environmental Footprint

Nowadays, “green analytical chemistry” challenges are to develop techniques which reduce the environmental impact not only in term of analysis but also in the sample preparation step. Within this objective, pressurized liquid extraction (PLE) was investigated to determine the initial composition of key antioxidants contained in rosemary leaves: Rosmarinic acid (RA), carnosic acid (CA), and carnosol (CO). An experimental design was applied to identify an optimized PLE set of extraction parameters: A temperature of 183 °C, a pressure of 130 bar, and an extraction duration of 3 min enabled recovering rosemary antioxidants. PLE was further compared to conventional Soxhlet extraction (CSE) in term of global processing time, energy used, solvent recovery, raw material used, accuracy, reproducibility, and robustness to extract quantitatively RA, CA, and CO from rosemary leaves. A statistical comparison of the two extraction procedure (PLE and CSE) was achieved and showed no significant difference between the two procedures in terms of RA, CA, and CO extraction. To complete the study showing that the use of PLE is an advantageous alternative to CSE, the eco-footprint of the PLE process was evaluated. Results demonstrate that it is a rapid, clean, and environmentally friendly extraction technique