Colchicine technique of chromosome doubling for soybean (Glycine max) and its wild relatives. First observations on agronomic characteristics on 'G. max' tetraploid plants

Colchicine technique of chromosome doubling for soybean (Glycine max) and its wild relatives. First observations on agronomic characteristics on 'G. max' tetraploid plant

Genotyping Durum Wheat using specific allelic capture: an application to detect QTL for WSSMV resistance

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Phylogenomics unravels the complex reticulated history and shifts in mating systems in wheat relatives (Aegilops/Triticum genus)

International audienceEvolution from outcrossing to selfing recurrently occurred in many groups of organisms, especially in plants. Although it could be advantageous on the short term, selfing is though to be a dead-end strategy because (i) selfing is expected to reduce the efficacy of selection and (ii) back transitions towards outcrossing are assumed to be unlikely. Genomic approaches allow both to reconstruct species and mating system histories and to investigate the genomic consequences of mating system transitions. The Aegilops/Triticum genus (wheat relatives) contains both self-incompatible and selfcompatible species with different degree of selfing. For all 13 diploid species of the genus and four outgroups we better characterized their mating systems by a combinations of morphological measures on several reproductive traits. For each species we also sequenced the transcriptome of at least two individuals (up to 10 or 20 individuals for some focal outcrossing and selfing species, respectively). First, we reconstructed the complex history of the genus. We confirmed one recently proposed event of genomic material exchange either through hybridization or intensive gene flow, and we pointed to at least a new, more recent, one. Mapping traits on this historical background reveals that self-incompatibility was ancestral and lost only once, followed by several independent evolution events towards more or less high selfing rates. Across species we found a strong negative association between the level of selfing and both polymorphism levels and selection efficacy. However, we did not find any evidence of relaxed selection efficacy on ancestral lineages leading to the extent selfing species, suggesting that high selfing habit is of recent origin. In addition to support the dead-end hypothesis, these results also provide a time-scale for the dynamics of selfing evolution

Pervasive hybridizations in the history of wheat relatives

Cultivated wheats are derived from an intricate history of three genomes, A, B, and D, present in both diploid and polyploid species. It was recently proposed that the D genome originated from an ancient hybridization between the A and B lineages. However, this result has been questioned, and a robust phylogeny of wheat relatives is still lacking. Using transcriptome data from all diploid species and a new methodological approach, our comprehensive phylogenomic analysis revealed that more than half of the species descend from an ancient hybridization event but with a more complex scenario involving a different parent than previously thought-Aegilops mutica, an overlooked wild species-instead of the B genome. We also detected other extensive gene flow events that could explain long-standing controversies in the classification of wheat relatives.De två första författarna delar förstaförfattarskapet.</p

Epistatic determinism of durum wheat resistance to the wheat spindle streak mosaic virus

UMR AGAP : équipe GE2popUMR BGPI : équipe 6KEY MESSAGE: The resistance of durum wheat to the Wheat spindle streak mosaic virus (WSSMV) is controlled by two main QTLs on chromosomes 7A and 7B, with a huge epistatic effect. Wheat spindle streak mosaic virus (WSSMV) is a major disease of durum wheat in Europe and North America. Breeding WSSMV-resistant cultivars is currently the only way to control the virus since no treatment is available. This paper reports studies of the inheritance of WSSMV resistance using two related durum wheat populations obtained by crossing two elite cultivars with a WSSMV-resistant emmer cultivar. In 2012 and 2015, 354 recombinant inbred lines (RIL) were phenotyped using visual notations, ELISA and qPCR and genotyped using locus targeted capture and sequencing. This allowed us to build a consensus genetic map of 8568 markers and identify three chromosomal regions involved in WSSMV resistance. Two major regions (located on chromosomes 7A and 7B) jointly explain, on the basis of epistatic interactions, up to 43% of the phenotypic variation. Flanking sequences of our genetic markers are provided to facilitate future marker-assisted selection of WSSMV-resistant cultivars

Effect of familial clustering in the genetic screening of 235 French ALS families

International audienceObjectives To determine whether the familial clustering of amyotrophic lateral sclerosis (ALS) cases and the phenotype of the disease may help identify the pathogenic genes involved. Methods We conducted a targeted next-generation sequencing analysis on 235 French familial ALS (FALS), unrelated probands to identify mutations in 30 genes linked to the disease. The genealogy, that is, number of cases and generations with ALS, gender, age, site of onset and the duration of the disease were analysed. Results Regarding the number of generations, 49 pedigrees had only one affected generation, 152 had two affected generations and 34 had at least three affected generations. Among the 149 pedigrees (63.4%) for which a deleterious variant was found, an abnormal G4C2 expansion in C9orf72 was found in 98 cases as well as SOD1 , TARBP or FUS mutations in 30, 9 and 7 cases, respectively. Considering pedigrees from the number of generations, abnormal G4C2 expansion in C9orf72 was more frequent in pedigrees with pairs of affected ALS cases, which represented 65.2% of our cohort. SOD1 mutation involved all types of pedigrees. No TARDBP nor FUS mutation was present in monogenerational pedigrees. TARDBP mutation predominated in bigenerational pedigrees with at least three cases and FUS mutation in multigenerational pedigrees with more than seven cases, on average, and with an age of onset younger than 45 years. Conclusion Our results suggest that familial clustering, phenotypes and genotypes are interconnected in FALS, and thus it might be possible to target the genetic screening from the familial architecture and the phenotype of ALS cases

Cerebral Venous Thrombosis: Clinical, Radiological, Biological, and Etiological Characteristics of a French Prospective Cohort (FPCCVT)-Comparison With ISCVT Cohort

International audienceIntroduction: Cerebral venous thrombosis (CVT) is a rare disease with highly variable clinical presentation and outcome. Etiological assessment may be negative. The clinical and radiological presentation and evolution can be highly variable. The mechanisms involved in this variability remain unknown.Objective: The aim of this multicenter French study registered on ClinicalTrials.gov (NCT02013635) was therefore to prospectively recruit a cohort of patients with cerebral venous thrombosis (FPCCVT) in order to study thrombin generation and clot degradation, and to evaluate their influence on clinical radiological characteristics. The first part of the study was to compare our cohort with a reference cohort.Methods: This prospective, multicenter, French study was conducted from July 2011 to September 2016. Consecutive patients (aged >15 years) referred to the stroke units of 21 French centers and who had a diagnosis of symptomatic CVT were included. All patients gave their written informed consent. The diagnosis of CVT had to be confirmed by imaging. Clinical, radiological, biological, and etiological characteristics were recorded at baseline, at acute phase, at 3 months and at last follow-up visit. Thrombophilia screening and the choice of treatment were performed by the attending physician. All data were compared with data from the International Study on CVT published by Ferro et al.Results: Two hundred thirty-one patients were included: 117 (50.6%) had isolated intracranial hypertension, 96 (41.5%) had focal syndrome. During hospitalization, 229 (99.1%) patients received anticoagulant treatment. Median length of hospital stay was 10 days. Five patients died during hospitalization (2.2%). At 3 months, 216 patients (97.0%) had follow-up with neurological data based on an outpatient visit. The mean duration of antithrombotic treatment was 9 months, and the mean time to last follow-up was 10.5 months. At the end of follow-up, eight patients had died, and 26 patients were lost to follow-up. At least one risk factor was identified in 200 patients.Conclusions: We demonstrated that the FPCCVT cohort had radiological, biological, and etiological characteristics similar to the historical ISCVT cohort. Nevertheless, the initial clinical presentation was less severe in our study probably due to an improvement in diagnostic methods between the two studies