Project description:We analyzed scRNA-seq data in human pluripotent stem cells derived neural tube models. This in vitro system recapitulates some key aspects of neural patterning in the entire neural tube, including both brain and SC regions, along both rostral-caudal and dorsal-ventral axes
Project description:Studies in animal models have been fundamental for understanding brain development but only a fraction of these findings have been validated in a human context. Here, we tissue-engineered a model (MiSTR) of human neural tube regionalization based on human embryonic stem cells (hESCs) and microfluidic cell culturing. By exposing differentiating hESCs to a WNT signalling gradient we mimicked early rostro-caudal neural patterning, and with >80% reproducibility generated a coherent tissue with progressive caudalization from forebrain over midbrain to hindbrain, including formation of isthmic organiser characteristics. Single-cell transcriptomics revealed that rostro-caudal organization was established already at 24 hours of differentiation, before expression of neural markers. Moreover, the transcriptomic hallmarks of rostro-caudal MiSTR organization accurately recapitulated gene expression patterns of the early rostro-caudal neural plate in mouse embryos. MiSTR thereby represents a novel in vitro model of human neurodevelopment to deconstruct and systematically analyze factors responsible for rostro-caudal neural tube patterning.
Project description:Maternal diabetes is a teratogen that can lead to neural tube closure defects in the offspring. We therefore sought to compare gene expression profiles at the site of neural tube closure between stage-matched embryos from normal dams, and embryos from diabetic dams. Neurulation-stage mouse embryos at 8.5 days of gestation were used to prepare neural tissue at the anterior aspect of neural tube closure site 1. Tissue was procured from the open neural tube immediately anterior of the closure site, and from the closed neural tube immediately posterior to the closure site by laser microdissection. For each sample, 10 sections were pooled, total RNA was extracted, and 7 ng of total RNA were used for expression profiling by Tag sequencing using an Applied Biosystems SolidSAGE kit for library construction, and an AB SOLiD 5500 XL instrument for sequencing. Sequence reads were mapped to RefSeq RNA, and count data per gene were obtained using a modified version of the Applied Biosystems SOLiDâ?¢ SAGEâ?¢ Analysis Software. diabetic dam - closed neural tube // diabetic dam - open neural tube // normal dam - closed neural tube // normal dam - open neural tube
Project description:At an incidence of approximately 1/1000 births, neural tube defects (NTDs) comprise one of the most common and devastating congenital disorders. In an attempt to enhance and expand our understanding of neural tube closure, we undertook a high-throughput gene expression analysis of the neural tube as it was forming in the mouse embryo. Open and closed sections of the developing neural tube were micro-dissected from mouse embryos, and hybridized to Affymetrix mouse expression arrays. Clustering of genes differentially regulated in open and closed sections of the developing neural tube highlighted molecular processes previously recognized to be involved in neural tube closure and neurogenesis. Analysis of the genes in these categories identified potential candidates underlying neural tube closure. In addition, we identified approximately 25 novel genes, of unknown function, that were significantly up-regulated in the closed neural tube. Based on their expression patterns in the developing neural tube, five novel genes are proposed as interesting candidates for involvement in neurogenesis. The high-throughput expression analysis of the neural tube as it forms allows for better characterization of pathways involved in neural tube closure and neurogenesis, and hopefully will strengthen the foundation for further research along the pathways dictating neural tube development.
Project description:The post-implantation embryo is subject to extensive growth, morphogenetic changes and lineage decisions that take place in utero and are therefore difficult to deconstruct in vivo. A robust in vitro culture system that mimics post-implantation mouse development would pave the path towards understanding the dynamics of these processes and how they are coupled. Small aggregates of mouse embryonic stem cells (mESCs) can undergo gastrulation-like events and elongation in vitro, resulting in aggregates with gene expression domains that reflect the post-occipital embryo (gastruloids1–3). However, these ordered patterns of gene expression do not correlate with embryo-like morphogenesis. Here we show that mechano-chemical manipulation of the aggregates results in Trunk-Like-Structures (TLS) with a high level of organization of the embryonic tissue layers, including the formation of a neural tube and somites. Comparative single-cell RNA-Seq (scRNA-Seq) of TLS and embryos demonstrated the molecular complexity of TLS, confirmed embryo-like gene-regulatory programs, and unveiled the presence of primordial germ cell like cells (PGCLCs). Finally, Tbx6-/- TLS formed ectopic neural tubes, recapitulating the in vivo phenotype. These results suggest that TLS are a powerful platform to study the morphogenetic changes and lineage decisions during post-implantation development in space and time.