Like all organs, the thymus grows in size and function rapidly during development, but this growth comes to a halt after birth. However, the molecular mechanisms behind such a transition in the thymus remain obscure. Using single-cell RNA sequencing (scRNA-seq) of the murine thymic stroma, we identified that major transcriptomic changes occur in the endothelium and mesenchyme across the transition to homeostasis.
View Article and Find Full Text PDFSingle-cell multiplex imaging (scMI) measures cell locations and phenotypes within a tissue and can be used to understand the tumor microenvironment. In scMI studies, it is often of interest to quantify spatial co-localization of immune cells and its association with clinical outcomes; however, it remains unknown which of the many available spatial indices have adequate power to detect spatial within-sample co-localization and its association with patient outcomes, such as survival. In this study, the performance of six frequentist metrics of spatial co-localization used in scMI studies were evaluated.
View Article and Find Full Text PDFVariation in body size has important implications for physical performance and fitness. For insects, adult size and morphology are determined by larval growth and metamorphosis. Female blue orchard bees, Osmia lignaria, (Say) provision a finite quantity of food to their offspring.
View Article and Find Full Text PDFSingle-cell RNA sequencing (scRNA-seq) resolves heterogenous cell populations in tissues and helps to reveal single-cell level function and dynamics. In neuroscience, the rarity of brain tissue is the bottleneck for such study. Evidence shows that, mouse and human share similar cell type gene markers.
View Article and Find Full Text PDFGenes (Basel)
August 2019
Rhabdomyosarcoma is subclassified by the presence or absence of a recurrent chromosome translocation that fuses the and or genes. The fusion protein (FOXO1-PAX3/7) retains both binding domains and becomes a novel and potent transcriptional regulator in rhabdomyosarcoma subtypes. Many studies have characterized and integrated genomic, transcriptomic, and epigenomic differences among rhabdomyosarcoma subtypes that contain the gene fusion and those that do not; however, few investigations have investigated how gene co-expression networks are altered by .
View Article and Find Full Text PDFTo fully utilize the power of single-cell RNA sequencing (scRNA-seq) technologies for identifying cell lineages and bona fide transcriptional signals, it is necessary to combine data from multiple experiments. We present BERMUDA (Batch Effect ReMoval Using Deep Autoencoders), a novel transfer-learning-based method for batch effect correction in scRNA-seq data. BERMUDA effectively combines different batches of scRNA-seq data with vastly different cell population compositions and amplifies biological signals by transferring information among batches.
View Article and Find Full Text PDFArthropod Struct Dev
September 2018
Insect metamorphosis involves a complex change in form and function. In this study, we examined the development of the solitary bee, Megachile rotundata, using micro-computed tomography (μCT) and volume analysis. We describe volumetric changes of brain, tracheae, flight muscles, gut, and fat bodies in prepupal, pupal, and adult M.
View Article and Find Full Text PDFStructures such as nests and burrows are an essential component of many organisms' life-cycle and require a complex sequence of behaviours. Because behaviours can vary consistently among individuals and be correlated with one another, we hypothesized that these structures would (1) show evidence of among-individual variation, (2) be organized into distinct functional modules and (3) show evidence of trade-offs among functional modules due to limits on energy budgets. We tested these hypotheses using the alfalfa leafcutting bee, Megachile rotundata, a solitary bee and important crop pollinator.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2017
Body size is an important phenotypic trait that correlates with performance and fitness. For determinate growing insects, body size variation is determined by growth rate and the mechanisms that stop growth at the end of juvenile growth. Endocrine mechanisms regulate growth cessation, and their relative timing along development shapes phenotypic variation in body size and development time.
View Article and Find Full Text PDFSpecies-specific biochemistry, morphology, and function of the Dufour's gland have been investigated for social bees and some non-social bee families. Most of the solitary bees previously examined are ground-nesting bees that use Dufour's gland secretions to line brood chambers. This study examines the chemistry of the cuticle and Dufour's gland of cavity-nesting Megachile rotundata and Osmia lignaria, which are species managed for crop pollination.
View Article and Find Full Text PDFIn holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diets are often complex and may interact with one another, necessitating the use of a geometric framework for elucidating nutritional effects. In the honey bee, , nurse bees provision food to developing larvae, directly moderating growth rates and caste development.
View Article and Find Full Text PDFJ Insect Physiol
July 2015
Insect metamorphosis is a complex developmental transition determined and coordinated by hormonal signaling that begins at a critical weight late in the larval phase of life. Even though this hormonal signaling is well understood in insects, the internal factors that are assessed at the critical weight and that drive commitment to metamorphosis have remained unresolved in most species. The critical weight may represent either an autonomous decision by the neuroendocrine system without input from other developing larval tissues, or an assessment of developmental thresholds occurring throughout the body that are then integrated by the neuroendocrine tissues.
View Article and Find Full Text PDFThe scaling laws governing metabolism suggest that we can predict metabolic rates across taxonomic scales that span large differences in mass. Yet, scaling relationships can vary with development, body region, and environment. Within species, there is variation in metabolic rate that is independent of mass and which may be explained by genetic variation, the environment or their interaction (i.
View Article and Find Full Text PDFJ Exp Biol
December 2013
Organisms must accommodate oxygen delivery to developing tissues as body mass increases during growth. In insects, the growth of the respiratory system has been assumed to occur only during molts, whereas body mass and volume increase during the larval stages between molts. This decouples whole-body growth from the growth of the oxygen supply system.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
November 2011
In some group-living organisms, labor is divided among individuals. This allocation to particular tasks is frequently stable and predicted by individual physiology. Social insects are excellent model organisms in which to investigate the interplay between physiology and individual behavior, as division of labor is an important feature within colonies, and individual physiology varies among the highly related individuals of the colony.
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