Utilizing Playdoh in the Classroom to Construct a 3D Model Depicting Cellular Movements and Tissue Remodeling during Human Gastrulation, Early Organogenesis, and Embryonic Folding

In classroom studies of mammalian embryology, students must fully grasp the cellular and tissue remodeling needed to initiate gastrulation to ensure comprehension of forthcoming developmental processes such as tissue specification and organogenesis. However, quickly and completely communicating three-dimensional concepts such as gastrulation, neurulation, and embryonic folding through common two-dimensional tools such as PowerPoint is challenging for students because this method lacks the spatial orientation needed to fully understand development.

Role of early management of hyperornithinaemia‐hyperammonaemia‐homocitrullinuria syndrome in pregnancy

Hyperornithinaemia-hyperammonaemia-homocitrullinuria (HHH) syndrome is a rare inherited metabolic disorder of the urea cycle. Few reports exist to guide practices during pregnancy and fetal delivery. Yet, with affected patients often surviving into reproductive age, appropriate management of the peripartum phase is essential to ensure positive maternal and fetal outcomes.Reassuringly, the vast majority of offspring of parturients with HHH syndrome have normal developmental outcomes; yet as seen here, fetal growth restriction does appear more frequently. Furthermore, in addition to the absent fetal corpus callosum observed in this case, other fetal cerebral abnormalities, including speech delay and intellectual impairment, have been recognised.Unregulated dietary intake is one proposed factor for the observed disruption in fetal growth and early cerebral development. These stipulations not only reinforce the importance of extensive planning and teamwork, but also demonstrate the importance of timely intervention by a metabolic dietician and dietary compliance in the early organogenesis stage of pregnancy.

Integrating central and peripheral neurons in elongating multi-lineage-organized gastruloids

Human stem cell technologies including self-assembling 3D tissue models provide unprecedented access to early neurodevelopment and enable fundamental insights into neuropathologies. Gastruloid models have yet to be used to investigate the developing nervous system. Here we generate elongating multi-lineage-organized (EMLO) gastruloids with trunk identity that co-develop central and peripheral nervous system (CNS, PNS) correlates. We track migrating neural crest cells that differentiate to form peripheral neurons integrated with an upstream spinal cord region. This follows initial EMLO polarization events, and is coordinated with primitive gut tube elongation and cardiomyocyte differentiation. By immunofluorescence of multi-lineage and functional biomarkers, we evaluate EMLOs over a twenty-two day period, and apply them to investigate the impact of mu opioid receptor modulation on neuronal activity. This comprehensive study demonstrates a novel combined CNS-PNS model of early organogenesis and integration events in the trunk to benefit human biomedical research.

High-Spatial-Resolution Multi-Omics Atlas Sequencing of Mouse Embryos via Deterministic Barcoding in Tissue

SUMMARYWe present DBiT-seq –Deterministic Barcoding in Tissue for spatial omics sequencing – for co-mapping of mRNAs and proteins in a formaldehyde-fixed tissue slide via NGS sequencing. Parallel microfluidic channels were used to deliver DNA barcodes to the surface of a tissue slide and crossflow of two sets of barcodes A1-50 and B1-50 followed by ligation in situ yielded a 2D mosaic of tissue pixels, each containing a unique full barcode AB. Application to mouse embryos revealed major tissue types in early organogenesis as well as fine features like microvasculature in a brain and pigmented epithelium in an eye field. Gene expression profiles in 10μm pixels conformed into the clusters of single-cell transcriptomes, allowing for rapid identification of cell types and spatial distributions. DBiT-seq can be adopted by researchers with no experience in microfluidics and may find applications in a range of fields including developmental biology, cancer biology, neuroscience, and clinical pathology.In BriefMicrofluidic deterministic barcoding of mRNAs and proteins in tissue slides followed by high-throughput sequencing enables the construction of a high-spatial-resolution multi-omics atlas at the genome scale. Application to mouse embryos (E10-12) identified major tissue types in early organogenesis and revealed fine tissue features such as retinal pigmented epithelium and endothelial microvasculature at the cellular level.HighlightsDeterministic barcoding in tissue enables NGS-based spatial multi-omics mapping.DBiT-seq identified spatial patterning of major tissue types in mouse embryos.DBiT-seq revealed fine features such as retinal pigmented epithelium and microvascular endothelium at the cellular level.Direct integration with scRNA-seq data allows for rapid cell type identification.

The protein repertoire in early vertebrate embryogenesis

SummaryWe present an unprecedentedly comprehensive characterization of protein dynamics across early development inXenopus laevis, available immediately via a convenient Web portal. This resource allows interrogation of the protein expression data in conjunction with other data modalities such as genome wide mRNA expression. This study provides detailed data for absolute levels of ∼14K uniqueXenopusproteins representing homologues of ∼9K unique human genes – a rich resource for developmental biologists. The purpose of this manuscript is limited to presenting and releasing the data browser.HighlightsRelative protein expression from stage IV oocyte, blastula, gastrula, neurula, and early organogenesisBiological triplicates with confidence intervals on protein expression reflect certainty in dynamic patternsConvenient time-series Web-browser integrated with the multi-media Xenbase portalGene-symbol search and multi-gene protein/mRNA juxtaposition capabilities