Project description:Innate regeneration following digit tip amputation is one of the few examples of epimorphic regeneration in mammals. Digit tip regeneration is mediated by the blastema, the same structure invoked during limb regeneration in some lower vertebrates. By genetic lineage analyses in mice, the digit tip blastema has been defined as a population of heterogeneous, lineage restructed progenitor cells. These previous studies, however, do not comprehensively evaluate blastema heterogeneity or address lineage restruction of closely related cell types. Here we report single cell RNA sequencing of over 38,000 cells from mouse digit tip blastemas and unamputated control digit tips and generate an atlas of the cell types participating in digit tip regeneration.
Project description:Innate regeneration following digit tip amputation is one of the few examples of epimorphic regeneration in mammals. Digit tip regeneration is mediated by the blastema, the same structure invoked during limb regeneration in some lower vertebrates. By genetic lineage analyses in mice, the digit tip blastema has been defined as a population of heterogeneous, lineage restructed progenitor cells. These previous studies, however, do not comprehensively evaluate blastema heterogeneity or address lineage restruction of closely related cell types. Here we report one additional single cell RNA sequencing sample (28 days post-amputation) to add to our already published 38,000 cells from mouse digit tip blastemas and unamputated control digit tips used to generate an atlas of the cell types participating in digit tip regeneration.
Project description:Identification of targets of the protein disulfide reductase thioredoxin using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and thiol specific differential labeling with isotope-coded affinity tags (ICAT). Reduction of specific target disulfides is quantified by measuring ratios of cysteine residues labeled with the heavy (13C) and light (12C) ICAT reagents in peptides derived from tryptic digests of Trx-treated and non-treated samples. Keywords: protein, LC-MS/MS, ICAT
Project description:The ongoing SARS-CoV-2 pandemic and subsequent demand for viral testing worldwide has led to major issues in scaling the efforts of diagnostic labs and even in securing basic supplies for collection and processing of samples. This has in turn led to worldwide efforts by the scientific community to establish improved protocols that are cheaper, more scalable, and not as resource intensive. One such effort resulted in an assay called “Swab-Seq”, which was so named because it was originally developed to work with dry nasal swab samples, but is actually flexible in terms of the sample type it can accommodate for testing. The assay adapts the existing gold standard (RNA extracted from a nasopharyngeal (NP) swab that is subjected to quantitative reverse transcription polymerase chain reaction, “qRT-PCR”) to a next-generation sequencing readout. By pairing this modification with extraction-free sampling techniques it is possible to achieve high scalability at low cost per sample, and a reasonable turnaround time for reporting results. We evaluated the effectiveness of this assay both on samples collected from asymptomatic individuals using the traditional NP swab and using alternative extraction-free sampling techniques, including saliva and a saline mouth gargle protocol, and found the assay to be highly sensitive (comparable to the standard qRT-PCR assay), flexible (adaptable to saliva and gargle samples stored at room temperature up to a week), and scalable (easily accommodating hundreds of samples at a time). Continued development in the future will lead to more effective testing regimes that reduce the burden of transmissible respiratory infections on the global community.
Project description:Current understanding of oocyte quality and developmental potential maintains that stochastic or epigenetic processes modulate the action of determinants that are laid in the oocyte during oogenesis. These determinants are considered to be rather conserved across mice, leading different strains of mice to be used interchangeably. We challenged this assumption and studied the relationship between oocyte composition and developmental quality in four inbred strains of mice, namely 129Sv, C57Bl/6, C3H/HeN and DBA/2J. These oocytes showed large variability developmental competence and embryo quality irrespective of the developmental stimulus (fertilization, somatic cell nuclear transfer, parthenogenesis). To unravel the molecular basis of the observed phenotypes we applied state-of-the-art proteomics (SILAC LC-MS/MS) combined with transcriptomics (RNA deep sequencing). We quantified 1839 proteins and 20413 transcripts simultaneously in oocytes of all four strains. The proteome and the transcriptome had little correlation with each other, highlighting the importance of proteomic quantifications in embryology. We found that proteins that were most variably expressed between oocytes from different strains mainly relate to oocyte biology, ribosome and RNA biogenesis as well as embryo differentiation and chromatin remodelling. Thus, different strains of mice should not be used interchangeably in biology when tackling questions about oogenesis and early development.
Project description:To better examine the molecular mechanisms behind the virus infection, we conducted a correlation analysis of RNA-Seq and quantitative iTRAQ-LC-MS/MS in TuMV-infected and in healthy Chinese cabbage leaves.