Project description:Human limbs emerge during the fourth post-conception week as mesenchymal buds, which develop into fully formed limbs over the subsequent months. This process is orchestrated by numerous temporally and spatially restricted gene expression programmes, making congenital alterations in phenotype common. Decades of work with model organisms have defined the fundamental mechanisms underlying vertebrate limb development, but an in-depth characterization of this process in humans has yet to be performed. Here we detail human embryonic limb development across space and time using single-cell and spatial transcriptomics. We demonstrate extensive diversification of cells from a few multipotent progenitors to myriad differentiated cell states, including several novel cell populations. We uncover two waves of human muscle development, each characterized by different cell states regulated by separate gene expression programmes, and identify musculin (MSC) as a key transcriptional repressor maintaining muscle stem cell identity. Through assembly of multiple anatomically continuous spatial transcriptomic samples using VisiumStitcher, we map cells across a sagittal section of a whole fetal hindlimb. We reveal a clear anatomical segregation between genes linked to brachydactyly and polysyndactyly, and uncover transcriptionally and spatially distinct populations of the mesenchyme in the autopod. Finally, we perform single-cell RNA sequencing on mouse embryonic limbs to facilitate cross-species developmental comparison, finding substantial homology between the two species.
Project description:To investigate into the evolutionary conversation of the single-cell transcriptome of human fetal limbs, especially the principles of forelimb and hindlimb specification and proximal-distal axis establishment, we collected the forelimbs and hindlimbs of mouse embryos matching human samples. We dissected the limbs to separate proximal, middle and distal parts and generated single-cell RNA-seq data of more than 70,000 cells. Combining this dataset with our human data, we are able to see highly conserved limb cell types and limb axis drivers. Several samples from already published studies GSM4227224, GSM4227225, GSM4227226, GSM4227227 (GSE142425) and GSM4498677, GSM4498678 (GSE149368) have been reused in data analyses and the corresponding processed data are also included with this submission.
Project description:We report here high-throughput RNA sequencing (RNA-seq) to characterise the transcriptional landscape of the embryonic chicken Müllerian duct during development.
Project description:Pancreas organogenesis is a highly dynamic process where neighbouring tissue interactions lead to dynamic changes in gene regulatory networks that orchestrates endocrine, exocrine and ductal lineage formation. To understand the spatio-temporal regulatory logic we have used the Forkhead transcription factor Foxa2-Venus fusion (FVF) knock-in reporter mouse to separate the FVF+ pancreatic epithelium from the FVF- surrounding mesenchyme and blood vessels to perform a whole genome-wide mRNA expression profiling at embryonic day (E)12.5-15.5. This allowed us to annotate genes and molecular processes differentially regulated in these cell types and compartments of the pancreas to generate a dynamic transcriptional landscape. Time-resolved profiling across four embryonic development days. Pancreata were FAC sorted by Foxa2-Venus Fusion (FVF) for each day with each 2-3 biological replicates.