Project description:The spine is a remarkably specialized skeletal structure, exhibiting distinct anatomical phenotypes across different spinal regions. With this understanding in mind, we hypothesized that skeletal stem cells (mSSCs) originating from various spinal regions (cervical, thoracic, and lumbar) might display varying genotypic signatures that may dictate their skeletal tissue formation and shape. We also analyzed femur SSCs as an additional control.
Project description:Over expression of MHC Class l protein in skeletal muscle causes myositis. Phenotype after expression in young mice is more severe. We performed gene expression profiling on young and adult mice after over expression of self MHC class l protein in skeletal muscle
Project description:Over expression of MHC Class l protein in skeletal muscle causes myositis. Phenotype after expression in young mice is more severe. We performed gene expression profiling on young and adult mice after over expression of self MHC class l protein in skeletal muscle Muscle from young ( early) , adult (Late) and cntrol (control) mice , n=3 each group, was used for gene expression profiling
Project description:Pathogenic variants of NOTCH2 that lead to a gain or loss of function are associated with serious clinical consequences. A recently reported novel NOTCH2 4006G>C variant was associated with decreased Notch signaling and skeletal fragility in humans and mouse (Notch2em1Ecan) lines. In the present study, we analyze the transcriptome of femoral bones from mature control and Notch2em1Ecan mice following the exclusion of hematological cells. Single cells were analyzed following microfluidic partitioning on a Chromium X instrument using a 3' gene expression library. Uniform manifold approximation and projection (UMAP) for non-linear dimensional reduction defined 15 different cell clusters comprised of macrophages, red blood cells, endothelial, vascular and smooth and striated muscle cells and cells of the osteoblast lineage. Notch2 and Hes1 were the prevalent Notch receptor and target gene in most clusters. Independent clustering analysis of transcriptomes from control and Notch2em1Ecan femurs revealed a 35 – 45% decrease in cells forming the osteogenic and a 50 – 55% decrease in cells comprising the vascular cluster in Notch2em1Ecan femurs. Expression of Hes1 was decreased in Notch2em1Ecan cells. Analysis of nascent transcripts (intron/exon sequences) using the scVelo pipeline revealed suppressed velocity in vascular and osteogenic clusters from Notch2em1Ecan cells implying decreased transcription of genes constituting these clusters. In conclusion, a novel NOTCH2 deleterious variant associated with skeletal fragility alters the osteogenic and vascular transcriptome in femurs from adult mice.
Project description:Sea urchins (echinoids) are common model organisms for research in developmental biology and for their transition from a bilateral larva into their post-metamorphic adult with pentaradial body symmetry. The adult also has a calcareous endoskeleton with a multimetameric pattern of continuously added elements, among them the namesake of this phylum, spines. Nearly all echinoids have both large primary spines, and an associated set of smaller secondary spines.We hypothesize that the secondary spines of the tropical variegated urchin species, Lytechinus variegatus, are morphologically and molecularly distinct structures from primary spines and not just small spines. To test this premise, we examined both spine types using light microscopy, micro-CT imaging, lectin labeling, transcriptomics, and fluorescent in situ hybridization (FISH). Our findings reveal basic similarities between the two types in mineral and cellular anatomy, but with clear differences in growth patterns, genes expressed, and in the location of gene expression within the two types of spines. In particular, secondary spines have non-overlapping, longitudinally concentrated growth bands that lead to a blunt and straight profile, and a distinct transcriptome involving the upregulation in many genes in comparison to the primary spines. Neural, ciliary, and extracellular matrix interacting factors are implicated in the differentially expressed gene (DEG) dataset, including two genes - ONECUT2 and an uncharacterized discoidin- and thrombospondin-containing protein - that show spine type- specific localizations in FISH, and may be of interest to ongoing work in urchin spine patterning.These results demonstrate that primary and secondary spines have overlapping but distinct molecular and biomineralized characteristics, suggesting unique developmental and regenerative mechanisms, and devotion to this spiny dermal phylum.
Project description:Aging animals undergo a variety of changes in molecular processes. Among these, the cellular circadian clock has been shown to change as animals age. Moreover, there is evidence that also core circadian clock proteins could influence the ageing behavior of vertebrates. To investigate the interplay between aging and the circadian clock, we studied circadian mRNA expression in skeletal muscles from young (8 weeks) and aged (80 weeks) mice. In order to detect differences in circadian patterns, we used microarray-based transcriptome-wide time series of mRNA expression, containing 16 independent measurements for both young and aged animals. Each individual time point consists of total RNA from hind limb skeletal muscles from 3 different animals. Young and aged mice where entrained to 12 hr/12 hr light-dark conditions. From these mice, hind limb skeletal muscles were extracted at different times of day, in order to measure circadian mRNA expression patterns.