Quantitative morphometric analysis of adult teleost fish by X-ray computed tomography

Vertebrate models provide indispensable paradigms to study development and disease. Their analysis requires a quantitative morphometric study of the body, organs and tissues. This is often impeded by pigmentation and sample size. X-ray micro-computed tomography (micro-CT) allows high-resolution volumetric tissue analysis, largely independent of sample size and transparency to visual light. Importantly, micro-CT data are inherently quantitative. We report a complete pipeline of high-throughput 3D data acquisition and image analysis, including tissue preparation and contrast enhancement for micro-CT imaging down to cellular resolution, automated data processing and organ or tissue segmentation that is applicable to comparative 3D morphometrics of small vertebrates. Applied to medaka fish, we first create an annotated anatomical atlas of the entire body, including inner organs as a quantitative morphological description of an adult individual. This atlas serves as a reference model for comparative studies. Using isogenic medaka strains we show that comparative 3D morphometrics of individuals permits identification of quantitative strain-specific traits. Thus, our pipeline enables high resolution morphological analysis as a basis for genotype-phenotype association studies of complex genetic traits in vertebrates

Prospective Environmental Life Cycle Assessment of Nanosilver T-Shirts

A cradle-to-grave life cycle assessment (LCA) is performed to compare nanosilver T-shirts with conventional T-shirts with and without biocidal treatment. For nanosilver production and textile incorporation, we investigate two processes: flame spray pyrolysis (FSP) and plasma polymerization with silver co-sputtering (PlaSpu). Prospective environmental impacts due to increased nanosilver T-shirt commercialization are estimated with six scenarios. Results show significant differences in environmental burdens between nanoparticle production technologies: The "cradle-to-gate" climate footprint of the production of a nanosilver T-shirt is 2.70 kg of CO2-equiv (FSP) and 7.67-166 kg of CO2-equiv (PlaSpu, varying maturity stages). Production of conventional T-shirts with and without the biocide triclosan has emissions of 2.55 kg of CO2-equiv (contribution from triclosan insignificant). Consumer behavior considerably affects the environmental impacts during the use phase. Lower washing frequencies can compensate for the increased climate footprint of FSP nanosilver T-shirt production. The toxic releases from washing and disposal in the life cycle of T-shirts appear to be of minor relevance. By contrast, the production phase may be rather significant due to toxic silver emissions at the mining site if high silver quantities are require

Probing the Hofmeister Effect with Ultrafast Core Hole Spectroscopy

In the current work, X-ray emission spectra of aqueous solutions of different inorganic salts within the Hofmeister series are presented. The results reflect the direct interaction of the ions with the water molecules and therefore, reveal general properties of the salt-water interactions. Within the experimental precision a significant effect of the ions on the water structure has been observed but no ordering according to the structure maker/structure breaker concept could be mirrored in the results indicating that the Hofmeister effect-if existent-may be caused by more complex interactions

Quantitative morphometric analysis of adult teleost fish by X-ray computed tomography

Abstract Vertebrate models provide indispensable paradigms to study development and disease. Their analysis requires a quantitative morphometric study of the body, organs and tissues. This is often impeded by pigmentation and sample size. X-ray micro-computed tomography (micro-CT) allows high-resolution volumetric tissue analysis, largely independent of sample size and transparency to visual light. Importantly, micro-CT data are inherently quantitative. We report a complete pipeline of high-throughput 3D data acquisition and image analysis, including tissue preparation and contrast enhancement for micro-CT imaging down to cellular resolution, automated data processing and organ or tissue segmentation that is applicable to comparative 3D morphometrics of small vertebrates. Applied to medaka fish, we first create an annotated anatomical atlas of the entire body, including inner organs as a quantitative morphological description of an adult individual. This atlas serves as a reference model for comparative studies. Using isogenic medaka strains we show that comparative 3D morphometrics of individuals permits identification of quantitative strain-specific traits. Thus, our pipeline enables high resolution morphological analysis as a basis for genotype-phenotype association studies of complex genetic traits in vertebrates

Movie1-medaka anterior gut

Aghaallaei-Gruhl et al-development-DEVELOP:2015:134098-movie

Data from: Identification, visualization and clonal analysis of intestinal stem cells in fish

Recently, a stochastic model of symmetrical stem cell division followed by neutral drift has been proposed for intestinal stem cells (ISCs). This division mode has been suggested to represent the predominant mode of stem cell progression in mammals. In contrast, stem cells in the retina of teleost fish show a preferential asymmetric division mode. To address whether the mode of stem cell division is following phylogenetic or ontogenetic routes we characterized and analysed the entire gastrointestinal system with a particular focus on ISCs in the teleost medaka (Oryzias latipes). We analysed the entire intestine in adult medaka by X-ray micro-computed tomography within the intact body and combined that analysis with the cellular and molecular composition of the intestinal system. This allowed correlating the 3D topography with functional domains of the intestinal system. Morphology and gene expression data consistently argue for a subdivision of the medaka intestine into a small and large intestine. Analysis of ISCs in proliferation assays and via genetically encoded lineage-tracing highlights a stem cell niche in the furrow between the long intestinal folds. This niche is functionally equivalent to the mammalian intestinal crypts and stem cells in this compartment are characterized by the expression of sox9, axin2 as well as lgr5, homologs of mammalian ISC markers, emphasizing the evolutionary conservation of the Wnt-pathway components in the stem cell niche of the intestine. Consistent with a preferential symmetric division mode of medaka ISCs, the stochastic, sparse initial labelling of ISCs ultimately resulted in extended labelled or unlabelled domains originating from single stem cells in the furrow niche contributing to both, homeostasis and growth. Thus different modes of stem cell division co-evolved within one organism, and in the absence of physical isolation in crypts, ISCs contribute to homeostatic growth

movie2-medaka-posterior gut

Aghaallaei-Gruhl et al-development-DEVELOP:2015:134098-movie-