A new system for lineage ablation is based on transgenic expression of a diphtheria toxin receptor (DTR) in mouse cells and application of diphtheria toxin (DT). To streamline this approach, we generated Cre-inducible DTR transgenic mice (iDTR) in which Cre-mediated excision of a STOP cassette renders cells sensitive to DT. We tested the iDTR strain by crossing to the T cell- and B cell-specific CD4-Cre and CD19-Cre strains, respectively, and observed efficient ablation of T and B cells after exposure to DT. In MOGi-Cre/iDTR double transgenic mice expressing Cre recombinase in oligodendrocytes, we observed myelin loss after intraperitoneal DT injections. Thus, DT crosses the blood-brain barrier and promotes cell ablation in the central nervous system. Notably, we show that the developing DT-specific antibody response is weak and not neutralizing, and thus does not impede the efficacy of DT. Our results validate the use of iDTR mice as a tool for cell ablation in vivo.

It is generally assumed that new genes would arise by gene duplication mechanisms, because the signals for regulation and transcript processing would be unlikely to evolve in parallel with a new gene function. We have identified here a transcript in the house mouse (Mus musculus) that has arisen within the past 2.5-3.5 million years in a large intergenic region. The region is present in many mammals, including humans, allowing us to exclude the involvement of gene duplication, transposable elements, or other genome rearrangements, which are typically found for other cases of newly evolved genes. The gene has three exons, shows alternative splicing, and is specifically expressed in postmeiotic cells of the testis. The transcript is restricted to species within the genus Mus and its emergence correlates with indel mutations in the 5' regulatory region of the transcript. A recent selective sweep is associated with the transcript region in M. m. musculus populations. A knockout in the laboratory strain BL6 results in reduced sperm motility and reduced testis weight. Our results show that cryptic signals for transcript regulation and processing exist in intergenic regions and can become the basis for the evolution of a new functional gene.

Herein, we report ap re-synthetic pore environment design strategy to achieve stable methyl-functionalized metalorganic frameworks (MOFs) for preferential SO 2 binding and thus enhanced low (partial) pressure SO 2 adsorption and SO 2 / CO 2 separation. The enhanced sorption performance is for the first time attributed to an optimal pore sizeb yi ncreasing methyl group densities at the benzenedicarboxylate linker in [Ni 2 (BDC-X) 2 DABCO] (BDC-X = mono-, di-, and tetramethyl-1,4-benzenedicarboxylate/terephthalate;D ABCO = 1,4-diazabicyclo[2,2,2]octane). Monte Carlo simulations and first-principles density functional theory (DFT) calculations demonstrate the key role of methyl groups within the pore surface on the preferential SO 2 affinity over the parent MOF. The SO 2 separation potential by methyl-functionalized MOFs has been validated by gas sorption isotherms,i deal adsorbed solution theory calculations,s imulated and experimental breakthrough curves,and DFT calculations.

2), it was presumed that anti-IgD Abs targeted resting B cells, and due to a lack of costimulatory molecules, these B cells tolerized MBP-specific T cells. Similarly, it was shown that passive transfer of B cells expressing a myelin peptide prevented the induction of EAE (6 -8) or even EAE relapses (9). One explanation why B cells induce tolerance of naive but not memory T cells might be the need for expression of costimulatory molecules by the APC to activate naive T cells, specifically B7-1 and/or B7-2, but resting B cells do not express these molecules. On the other hand, memory T cells may not need costimulation and could therefore be activated by B cells. A problem of this hypothesis is that also activated B cells, which normally do express B7 molecules, can induce tolerance of T cells (10). It is therefore not clear whether it is indeed the absence of costimulation what causes B cells to induce tolerance.To study the role of B cells in tolerance induction we have generated mice that express an MHC class II-restricted immunodominant T cell epitope of myelin oligodendrocyte glycoprotein (MOG) specifically on B cells. These mice were found to be resistant to EAE induction. We could show that, following interaction of naive T cells with B cells presenting their specific Ag, T cells are partially activated, resulting in very marginal proliferation and up-regulation of coinhibitory molecules such as CTLA-4, B and T lymphocyte attenuator (BTLA), PD-1, and CD5. Subsequent in vivo activation of tolerized T cells leads to their deletion. Thus, we assessed that naive B cells induce peripheral tolerance by inducing expression of negative costimulatory molecules by Ag-specific T cells, followed by Ag-induced cell death (AICD) upon the next Ag encounter. Materials and Methods Generation of invariant chain (Ii) MOG miceThe targeting vector ROSA26STOP*IiMOG was constructed by introduction into the XbaI site of the vector ROSA26 -1 (11); a gift from P. Soriano (Fred Hutchinson Cancer Research Center, Seattle, WA) of a fragment comprising (5Ј to 3Ј): adenoviral splice acceptor, loxP, 2ϫ SV40 polyadenylation signal, FRT-flanked pGK-neo, a STOP cassette (12), loxP, mutant invariant chain (termed IiMOG), and bovine poly(A). The mutant invariant chain (IiMOG) was generated by assembly PCR on Ii template cDNA (derived from plasmid pcEX V3 mIi31, carrying the cDNA of the

Changes in gene expression are known to occur between closely related species, but it is not yet clear how many of these are due to random fixation of allelic variants or due to adaptive events. In a microarray survey between subspecies of the Mus musculus complex, we identified the mitogen-activated protein-kinase-kinase MKK7 as a candidate for change in gene expression. Quantitative PCR experiments with multiple individuals from each subspecies confirmed a specific and significant up-regulation in the testis of M. m. domesticus. Northern blot analysis shows that this is due to a new transcript that is not found in other tissues, nor in M. m. musculus. A cis-trans test via allele specific expression analysis of the MKK7 gene in F1 hybrids between domesticus and musculus shows that the expression change is mainly caused by a mutation located in cis. Nucleotide diversity was found to be significantly reduced in a window of at least 20 kb around the MKK7 locus in domesticus, indicative of a selective sweep. Because the MKK7 gene is involved in modulating a kinase signalling cascade in a stress response pathway, it seems a plausible target for adaptive differences between subspecies, although the functional role of the new testis-specific transcripts will need to be further studied

Iridium oxide (IrOx-NP) and palladium nanoparticles (Pd-NP) were supported on a 2,6-dicyanopyridine-based covalent-triazine framework (DCP-CTF) by energy-saving and sustainable microwave-assisted thermal decomposition reactions in propylene carbonate and in the ionic liquid [BMIm][NTf2]. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) confirm well-distributed NPs with sizes from 2 to 13 nm stabilized on the CTF particles. Metal contents between 10 and 41 wt% were determined by flame atomic absorption spectroscopy (AAS). Nitrogen sorption measurements of the metal-loaded CTFs revealed Brunauer–Emmett–Teller (BET) surface areas between 904 and 1353 m2 g−1. The composites show superior performance toward the hydrogen evolution reaction (HER) with low overpotentials from 47 to 325 mV and toward the oxygen reduction reaction (ORR) with high half-wave potentials between 810 and 872 mV. IrOx samples in particular show high performances toward HER while the Pd samples show better performance toward ORR. In both reactions, electrocatalysts can compete with the high performance of Pt/C. Exemplary cyclic voltammetry durability tests with 1000 cycles and subsequent TEM analyses show good long-term stability of the materials. The results demonstrate the promising synergistic effects of NP-decorated CTF materials, resulting in a high electrocatalytic activity and stability.

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Single‐cell RNA sequencing (scRNA‐seq) enables characterizing the cellular heterogeneity in human tissues. Recent technological advances have enabled the first population‐scale scRNA‐seq studies in hundreds of individuals, allowing to assay genetic effects with single‐cell resolution. However, existing strategies to analyze these data remain based on principles established for the genetic analysis of bulk RNA‐seq. In particular, current methods depend on a priori definitions of discrete cell types, and hence cannot assess allelic effects across subtle cell types and cell states. To address this, we propose the Cell Regulatory Map (CellRegMap), a statistical framework to test for and quantify genetic effects on gene expression in individual cells. CellRegMap provides a principled approach to identify and characterize genotype–context interactions of known eQTL variants using scRNA‐seq data. This model‐based approach resolves allelic effects across cellular contexts of different granularity, including genetic effects specific to cell subtypes and continuous cell transitions. We validate CellRegMap using simulated data and apply it to previously identified eQTL from two recent studies of differentiating iPSCs, where we uncover hundreds of eQTL displaying heterogeneity of genetic effects across cellular contexts. Finally, we identify fine‐grained genetic regulation in neuronal subtypes for eQTL that are colocalized with human disease variants.