University of Rennes

About: University of Rennes is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Catalysis. The organization has 18404 authors who have published 40374 publications receiving 995327 citations.

Genotype-phenotype relationships in Berardinelli-Seip congenital lipodystrophy

Abstract: Generalised lipodystrophy of the Berardinelli-Seip type (BSCL) is a rare autosomal recessive human disorder with severe adverse metabolic consequences. A gene on chromosome 9 (BSCL1) has recently been identified, predominantly in African-American families. More recently, mutations in a previously undescribed gene of unknown function (BSCL2) on chromosome 11, termed seipin, have been found to be responsible for this disorder in a number of European and Middle Eastern families. We have studied the genotype/phenotype relationships in 70 affected subjects from 44 apparently unrelated pedigrees of diverse ethnic origin. In all subjects, hepatic dysfunction, hyperlipidaemia, diabetes mellitus, and hypertrophic cardiomyopathy were significant contributors to morbidity with no clear differences in their prevalence between subjects with BSCL1 or BSCL2 and those with evidence against cosegregation with either chromosome 9 or 11 (designated BSCLX). BSCL2 appears to be a more severe disorder than BSCL1 with a higher incidence of premature death and a lower prevalence of partial and/or delayed onset of lipodystrophy. Notably, subjects with BSCL2 had a significantly higher prevalence of intellectual impairment than those with BSCL1 or BSCLX (p<0.0001, OR 17.0, CI 3.6 to 79.0). The higher prevalence of intellectual impairment and the increased risk of premature death in BSCL2 compared to BSCL1 emphasise the importance of molecular diagnosis of this syndrome and have clear implications for genetic counselling.

Environmental DNA surveillance for invertebrate species: advantages and technical limitations to detect invasive crayfish Procambarus clarkii in freshwater ponds.

Abstract: 1. The introduction of non-native species is a major threat to biodiversity. While eradication programs of well-established invaders are costly and hazardous for non-target species, the early detection of a non-native species at low density is critical for preventing biological invasions in recipient ecosystems. Recent studies reveal that environmental DNA (eDNA) is a powerful tool for detecting target species in aquatic ecosystems, but these studies focus mostly on fish and amphibians.2. We examine the reliability of using eDNA to detect the presence of an invasive freshwater crustacean species, the red swamp crayfish Procambarus clarkii. Species-specific primers and probes were designed; their specificity was tested using in silico PCR simulations and against tissues of other crayfish species. Limits of detection and quantification were specified for the target DNA sequence by means of quantitative PCR amplifications on dilution series of known amount of P. clarkii DNA.3. The method was applied to water samples collected in 158 ponds in a French Nature Park, and results were compared to a traditional method using food-baited funnel traps. Environmental DNA had a better detection efficiency but predominantly led to divergent results compared with the trapping method. While habitat features partly explained the failure of crayfish detection by trapping, detection by eDNA was problematic at low crayfish abundances. When P. clarkii was detected, the estimated concentrations of crayfish DNA in water samples were always below the limit of quantification for the target DNA sequence.4. Synthesis and applications. The combination of environmental DNA (eDNA) and conventional trapping methods is recommended to monitor the invasion by P. clarkii in small waterbodies such as ponds. However, the risk of mortality for non-target species, notably amphibians, has to be carefully evaluated before large-scale deployment of traps. Contrary to fish and amphibians, a low amount of extracellular DNA in water is suspected to be the major limitation for crayfish detection by molecular approaches. Current advancements in PCR technology, together with optimization of the water sampling method, promise upcoming developments of eDNA detection for aquatic invertebrate species.

Photomanipulation of a droplet by the chromocapillary effect.

Abstract: Liquid droplets can be manipulated in a controlled fashion along trajectories of any desired shape (such as a heart, see picture) by using light to create a wavelength-dependent interfacial tension gradient at a liquid/liquid interface. In this new phenomenon, the "chromocapillary effect", an interfacial flow generates droplet motion in the direction opposite to the gradient.