Role of the Nodule Inception promoter in the evolutionary gain of the nitrogen-fixing root nodule symbiosis

To overcome nutrient limitations, plants engage in two main types of root endosymbioses with beneficial microbes. Arbuscular mycorrhiza (AM) is an ancient symbiosis formed by about 70-90 % of land plants and phosphate-acquiring fungi of the phylum Glomeromycota. By contrast, root nodule symbiosis (RNS) with nitrogen-fixing bacteria is evolutionary much younger and is phylogenetically restricted to a single clade of flowering plants comprising only four orders, the Fabales, Fagales, Cucurbitales and Rosales (FaFaCuRo). AM and RNS require a common set of plant genes – the common symbiosis genes – and it is believed that genes that evolved for AM development have been recruited during the evolution of RNS to enable intracellular uptake and accommodation of bacteria. Moreover, RNS is characterised by the formation of a novel organ, the root nodule, and it was hypothesised that part of the lateral root (LR) developmental program was co-opted for nodule formation. The restricted occurrence of RNS calls for yet unidentified trait acquisitions and genetic changes in the last common ancestor of the FaFaCuRo clade. Using a phylogenomic approach, a cis-regulatory element (PACE) was discovered to be exclusively present in the promoter of the transcription factor gene Nodule Inception (NIN) of FaFaCuRo member species. NIN is positioned at the top of a RNS-specific transcriptional regulatory cascade and is indispensable for RNS. We found that PACE is essential for restoring infection threads (ITs) in Lotus japonicus nin mutants. PACE sequence variants from RNS-competent species appear functionally equivalent. Evolutionary loss or mutation of PACE is associated with loss of this symbiosis. PACE dictates gene expression in cortical cells forming IT and PACE-driven NIN expression restores the formation of cortical ITs, also when engineered into the NIN promoter of tomato. Our data pinpoint PACE as a key evolutionary invention that connected NIN to a pre-existing signal transduction cascade that governs the intracellular accommodation of AM fungi. This connection enabled bacterial uptake into plant cells via ITs, a unique and unifying feature of this symbiosis. Symbiosis signalling and LR development are tightly interconnected and treatment with lipochito-oligosaccharide molecules produced by AM fungi and rhizobia induce LR formation. To gain insight into the molecular players that connect these two distinct signalling programs, we studied the role of three common symbiosis genes Symbiosis Receptor Kinase (SymRK), Calcium Calmodulin-dependent kinase (CCaMK) and Cyclops, and of NIN in the formation of LRs. We reported that deregulated versions of SymRK, CCaMK, and Cyclops significantly increase the number of LRs in L. japonicus in a NIN-dependent manner and that ectopic expression of NIN likewise results in a significant increase in LR numbers. Additionally, NIN is necessary for LR induction mediated by both AM fungi and rhizobia bacteria. Our data reveal NIN as a key ranscriptional regulator that does not only employ parts of the LR evelopmental program for nodule organogenesis but also directly activates the development of LRs in a symbiotic context. Taken together, our data underpin the essential role of NIN in the evolutionary gain of RNS

Réalisation d'un capteur d'images matriciel avec sortie numérique

Cet article présente un prototype de capteur d'images conçu au laboratoire LE2I du Creusot. Il est réalisé sous la forme d'un ASIC en technologie Cmos 1.0mm. Il est destiné à être utilisé en contrôle qualité par vision artificielle pour des scènes présentant de forts contrastes lumineux. Un procédé original de numérisation du niveau de gris permet de contourner la notion classique de temps d'exposition variable et de traiter aisément les problèmes d'éblouissement local. Il permet également d'ouvrir de larges perspectives dans le domaine des capteurs intelligents, en effet la numérisation de l'information au niveau même du photosite permet, à terme d'envisager l'intégration d'un classifieur dans le voisinage immédiat du pixel, et de fournir une décision binaire en sortie du capteur

An unusual cause of granulomatous disease

BACKGROUND: Chronic granulomatous disease (CGD) is an inherited disorder of phagocytic cells caused by an inability to generate active microbicidal oxygen species required kill certain types of fungi and bacteria. This leads to recurrent life-threatening bacterial and fungal infections with tissue granuloma formation. CASE PRESENTATION: We describe a case of X-linked Chronic granulomatous disease (CGD) diagnosed in an 18-year-old male. He initially presented with granulomatous disease mimicking sarcoidosis and was treated with corticosteroids. He subsequently developed Burkholderia cepacia complex pneumonia and further investigation confirmed a diagnosis of CGD. CONCLUSION: Milder phenotypes of CGD are now being recognised. CGD should be considered in patients of any age with granulomatous diseases, especially if there is a history of recurrent or atypical infection

A novel point mutation in the CYBB gene promoter leading to a rare X minus chronic granulomatous disease variant — Impact on the microbicidal activity of neutrophils

AbstractThis article reports an atypical and extremely rare case of X-linked CGD in an Italian family characterized by a low expression of gp91phox (X91− CGD). A novel point mutation in the CYBB gene's promoter (insertion of a T at position −54T to −56T) appeared to prevent the full expression of this gene in the patient's neutrophils and correlated with a residual oxidase activity in the whole cells population. The expression and functional activity of the oxidase in eosinophils appeared to be almost normal. Gel shift assays indicated that the mutation led to decreased interactions with DNA-binding proteins. The total O2− production in the patient's granulocytes (5–7% of normal) supported no microbicidal power after 45 min and 60 min of contact with S. aureus and C. albicans, respectively. Despite this residual oxidase activity, the patients suffered from severe and life-threatening infections. It was concluded that in these X91− CGD neutrophils, the O2− production per se was not sufficient to protect the patient against severe infections

The impact of HIV and antiretroviral therapy on TB risk in children: a systematic review and meta-analysis.

BACKGROUND: Children (<15 years) are vulnerable to TB disease following infection, but no systematic review or meta-analysis has quantified the effects of HIV-related immunosuppression or antiretroviral therapy (ART) on their TB incidence. OBJECTIVES: Determine the impact of HIV infection and ART on risk of incident TB disease in children. METHODS: We searched MEDLINE and Embase for studies measuring HIV prevalence in paediatric TB cases ('TB cohorts') and paediatric HIV cohorts reporting TB incidence ('HIV cohorts'). Study quality was assessed using the Newcastle-Ottawa tool. TB cohorts with controls were meta-analysed to determine the incidence rate ratio (IRR) for TB given HIV. HIV cohort data were meta-analysed to estimate the trend in log-IRR versus CD4%, relative incidence by immunological stage and ART-associated protection from TB. RESULTS: 42 TB cohorts and 22 HIV cohorts were included. In the eight TB cohorts with controls, the IRR for TB was 7.9 (95% CI 4.5 to 13.7). HIV-infected children exhibited a reduction in IRR of 0.94 (95% credible interval: 0.83-1.07) per percentage point increase in CD4%. TB incidence was 5.0 (95% CI 4.0 to 6.0) times higher in children with severe compared with non-significant immunosuppression. TB incidence was lower in HIV-infected children on ART (HR: 0.30; 95% CI 0.21 to 0.39). Following initiation of ART, TB incidence declined rapidly over 12 months towards a HR of 0.10 (95% CI 0.04 to 0.25). CONCLUSIONS: HIV is a potent risk factor for paediatric TB, and ART is strongly protective. In HIV-infected children, early diagnosis and ART initiation reduces TB risk. TRIAL REGISTRATION NUMBER: CRD42014014276

The Clinical Variability of Maternally Inherited Diabetes and Deafness Is Associated with the Degree of Heteroplasmy in Blood Leukocytes

Context: Maternally inherited diabetes and deafness (MIDD) is a rare form of diabetes with a matrilineal transmission, sensorineural hearing loss, and macular pattern dystrophy due to an A to G transition at position 3243 of mitochondrial DNA (mtDNA) (m.3243A&gt;G). The phenotypic heterogeneity of MIDD may be the consequence of different levels of mutated mtDNA among mitochondria in a given tissue. Objective: The aim of the present study was thus to ascertain the correlation between the severity of the phenotype in patients with MIDD and the level of heteroplasmy in the blood leukocytes. Participants: The GEDIAM prospective multicenter register was initiated in 1995. Eighty-nine Europid patients from this register, with MIDD and the mtDNA 3243A&gt;G mutation, were included. Patients with MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) or with mitochondrial diabetes related to other mutations or to deletions of mtDNA were excluded. Results: A significant negative correlation was found between levels of heteroplasmy and age of the patients at the time of sampling for molecular analysis, age at the diagnosis of diabetes, and body mass index. After adjustment for age at sampling for molecular study and gender, the correlation between heteroplasmy levels and age at the diagnosis of diabetes was no more significant. The two other correlations remained significant. A significant positive correlation between levels of heteroplasmy and HbA1c was also found and remained significant after adjustment for age at molecular sampling and gender. Conclusions: These results support the hypothesis that heteroplasmy levels are at least one of the determinants of the severity of the phenotype in MIDD. Heteroplasmy levels are at least one of the determinants of the severity of the phenotype of maternally inherited diabetes and deafness

"Velhos são os Trapos": do positivismo clássico à nova era

Para que o ser humano consiga concretizar o direito à vida plena e digna, para que se justifique completamente a procura pela longevidade, deve socialmente permitir-se que essa vida maior seja igualmente melhor. Para que isso aconteça algo tem que mudar nas representações da velhice, no respeito pelas particularidades que a envolvem e pela oferta de estruturas específicas. A velhice é uma fase da vida que tem sido socialmente desvalorizada, negativamente representada, o que se reflete na qualidade de vida dos idosos. Esse ensaio reflexivo pretende desvelar os principais debates culturais sobre a velhice, ao analisar duas estruturas ideológicas dicotômicas sobre o envelhecimento e a velhice. Os resultados são defensores da necessidade de construção de imagens positivas sobre o envelhecimento, para combater os tradicionais modelos de declínio e de despessoalização. Realça-se a complexidade e a heterogeneidade dos fenômenos em análise sublinhando a aplicação de novas estratégias destinadas à construção de uma nova era sobre a velhice, ancorada nos paradigmas de cidadania e pluralidade sociais.For human beings to fulfil their right to live a full and dignified life, to completely justify the quest for longevity, it must be socially possible for that greater life to be also a better one. For this to occur, something needs to change in the representations of old age, in the respect for its particularities, and in the supply of specific structures. Old age is a stage of life that has been socially devalued, being represented in a negative way. This reflects on the quality of life of older people. This reflexive essay shall explore the main cultural debates regarding old age by analysing two dichotomic ideological structures on aging and old age. The results defend the need to build positive images regarding aging in order to fight the traditional models of decline and depersonalization. Noteworthy is the complexity and heterogeneity of the phenomena being analysed, highlighting the application of new strategies in order to build a new era for old age anchored on the social paradigms of citizenship and plurality