Association genetics to identify genes involved in aggressiveness traits in the plant pathogenic fungus Mycosphaerellafijiensis

National audienceThe fungal pathogen Mycosphaerellafijiensis causing black leaf streak disease of banana may be able to adapt to quantitatively resistant cultivars through changes in its aggressiveness. To understand this adaptation, it is necessary to determine the genetic basis of the aggressiveness traits involved. This study aims to identify genes of aggressiveness traits using a genome wide association study (GWAS) approach. About 130 M. fijiensis isolates were collected on susceptible and quantitatively resistant banana trees in three different locations in Cuba. The genome of these isolates was then sequenced and SNP (single nucleotide polymorphism)calling was performed. There was low genetic structure between the three Cuban populations (Fst=0.055). Linkage disequilibrium (LD) declined o 50% within about 6kb. The population mutation rate theta first estimate was 0.06%.A phenotype study was conducted to assess some aggressiveness traits using inoculations under controlled conditions : the number of symptoms and their total surface. Based on our variance analysis, we decided to use a simplified linear model taking only the cultivar and isolate effects into account, to calculate least-square means. These preliminary analyses showed that the samples analyzed satisfy conditions to conduct a GWAS analysis (reasonable LD, limited population structure and phenotypic variability for the quantitative traits considered). Such a study is currently being performed using the GAP-IT R package association genetics variant calling aggressiveness GWAS fungal pathoge

Transient modifications of the olfactory bulb on MR follow-up of COVID-19 patients with related olfactory dysfunction

International audienceBackground: : Olfactory dysfunction (OD) has been reported with a high prevalence on mild to moderate COVID-19 patients. Previous reports suggest that volume and signal intensity of olfactory bulbs (OB) have been reported as abnormal on acute phase of COVID-19 anosmia, but a prospective MRI and clinical follow-up study of COVID-19 patients presenting with OD was missing, aiming at understanding the modification of OB during patients'follow-up. Methods: : A prospective multicenter study was conducted including 11 COVID-19 patients with OD. Patients underwent MRI and psychophysical olfactory assessments at baseline and 6-month post-COVID-19. T2 FLAIR-Signal intensity ratio (SIR) was measured between the average signal of the OB and the average signal of white matter. OB volumes and obstruction of olfactory clefts (OC) were evaluated at both evaluation times. Results: : The psychophysical evaluations demonstrated a 6-month recovery in 10/11 patients (90.9%). The mean values of OB-SIR significantly decreased from baseline (1.66±0.24) to 6-month follow-up (1.35±0.27), reporting a mean variation of -17.82±15.20 % (p<0.001). The mean values of OB volumes significantly decreased from baseline (49.22±10.46 mm3) to 6-month follow-up (43.70±9.88 mm3), (p=0.006). Conclusion: : Patients with demonstrated anosmia reported abnormalities in OB imaging that may be objectively evaluated with the measurement of SIR and OB volumes. SIR and OB volumes significantly normalized when patient recovered smell. This supports the underlying mechanism of a transient inflammation of the OB as a cause of Olfactory Dysfunction in COVID-19 patients

French lacquers of the 18th century and vernis Martin

International audienceThe Martin family created a taste for Parisian lacquers , painted and varnished objects. The purpose of the work presented here was to gather new data on the construction materials, and to detail the varnishing and painting techniques used on these types of objects during the 18th century in France. A large body of French lacquers was studied using a comprehensive approach combining examinations, physico-chemical analyses and a reconstruction of the manufacturing steps used to create the artworks. Parisian lacquers are complex objects, consisting of a succession of five or six levels with specific functions, themselves made up of several layers, and detailed in successive phases during the creation process

Potential selection of genetically balanced spermatozoa based on the hypo-osmotic swelling test in chromosomal rearrangement carriers

International audienceChromosomal translocations and other balanced rearrangements, although usually associated with a normal phenotype, can lead to the transmission of an abnormal unbalanced genome to the offspring. Balanced and unbalanced spermatozoa, being indistinguishable, cannot be selected or deselected for prior to IVF and pre-implantation genetic diagnosis. Spermatozoa from 16 chromosomal rearrangement carriers were studied. After incubation in a hypo-osmotic solution (hypo-osmotic swelling test, or HOST), spermatozoa were fixed on microscope slides. The chromosomally balanced or unbalanced status corresponding to each observed class of flagellar conformation was evaluated through fluorescent in-situ hybridization (FISH). We show here a specific type of spermatozoa, with a distinct flagellar conformation that was associated with a balanced genetic content. HOST is a simple, low-cost and time-honoured procedure initially developed to distinguish immotile viable from non-viable spermatozoa. We demonstrate that it can also be used to identify genetically balanced spermatozoa in chromosomal rearrangement carriers, with a 96% decrease in the proportion of unbalanced spermatozoa after selection. This may potentially improve reproductive prognosis in affected couples if used prior to pre-implantation genetic diagnosis (PGD), and clinical utility and efficacy should be evaluated in further studies

Association of Maternal First Trimester Serum Levels of Free Beta Human Chorionic Gonadotropin and Hypospadias: A Population Based Study

Purpose:Human chorionic gonadotropin stimulates fetal testosterone production and contributes to normal development of male genitalia. Using population based data we hypothesized that differences in maternal free beta human chorionic gonadotropin may be associated with hypospadias.Materials and Methods:Data were obtained from the Paris Registry of Congenital Malformations (REMAPAR) (2011 to 2016). The initial study population included 3,172 pregnant women who gave birth to a singleton live born male infant with a congenital malformation. After exclusion of cases with unknown beta human chorionic gonadotropin and those with chromosomal or genetic abnormalities, the study population included 194 boys with isolated hypospadias and 1,075 controls. For cases with operative notes (125) we obtained data on type (proximal/distal) of hypospadias. Using quantile regression we compared median values of multiple of median beta human chorionic gonadotropin measured for first trimester Down syndrome screening (10th to 13th gestational weeks) for overall as well as by type of hypospadias vs controls. We also considered possible effects of placental dysfunction (maternal age, intrauterine growth retardation and preterm births) as potential confounding factors.Results:Overall the median beta human chorionic gonadotropin multiple of median was comparable for women who had an infant with hypospadias vs controls (0.99 vs 0.95, p=0.3). However, proximal hypospadias was associated with a statistically significant higher median multiple of median than distal hypospadias or unspecified (1.49 vs 0.92 vs 1.05, p=0.02). The estimates were comparable after adjustment for placental dysfunction.Conclusions:Our findings support the hypothesis that an alteration in maternal beta human chorionic gonadotropin levels is associated with hypospadias. However, this association appears to be limited to proximal hypospadias

Impact of the COVID-19 pandemic on disease stage and treatment for patients with pancreatic adenocarcinoma: A French comprehensive multicentre ambispective observational cohort study (CAPANCOVID)

International audienceBackground: The COVID-19 pandemic caused major oncology care pathway disruption. The CAPANCOVID study aimed to evaluate the impact on pancreatic adenocarcinoma (PA) - from diagnosis to treatment - of the reorganisation of the health care system during the first lockdown.Methods: This multicentre ambispective observational study included 833 patients diagnosed with PA between September 1, 2019 and October 31, 2020 from 13 French centres. Data were compared over three periods defined as before the outbreak of COVID-19, during the first lockdown (March 1 to May 11, 2020) and after lockdown.Results: During the lockdown, mean weekly number of new cases decreased compared with that of pre-pandemic levels (13.2 vs. 10.8, -18.2%; p = 0.63) without rebound in the post-lockdown period (13.2 vs. 12.9, -1.7%; p = 0.97). The number of borderline tumours increased (13.6%-21.7%), whereas the rate of metastatic diseases rate dropped (47.1%-40.3%) (p = 0.046). Time-to-diagnosis and -treatment were not different over periods. Waiting neoadjuvant chemotherapy in resectable tumours was significantly favoured (24.7%-32.6%) compared with upfront surgery (13%-7.8%) (p = 0.013). The use of mFOLFIRINOX preoperative chemotherapy regimen decreased (84.9%-69%; p = 0.044). After lockdown, the number of borderline tumours decreased (21.7%-9.6%) and advanced diseases increased (59.7%-69.8%) (p = 0.046). SARS-CoV-2 infected 39 patients (4.7%) causing 5 deaths (12.8%).Conclusion: This cohort study suggests the existence of missing diagnoses and of a shift in disease stage at diagnosis from resectable to advanced diseases with related therapeutic modifications whose prognostic consequences will be known after the planned follow-up.Trial registration: Clinicaltrials.gov NCT04406571