bioRxiv Science⌕ Search

bioRxiv · 10.1101/2023.08.23.554446

Primate-expressed EPIREGULIN promotes basal progenitor proliferation in the developing neocortex

Abstract

Neocortex expansion during evolution is linked to higher numbers of neurons thought to result from increased proliferative capacity and neurogenic potential of basal progenitor cells (BPs) during development. Here we show that EREG, encoding the growth factor EPIREGULIN, is expressed in the human developing neocortex and in gorilla organoids, but not in the mouse neocortex. Addition of EPIREGULIN to the mouse neocortex increases proliferation of BPs via EGFR-mediated signaling, whereas ablation of EREG in human cortical organoids reduces BP proliferation. Addition of EPIREGULIN to cortical organoids promotes a further increase in proliferation of gorilla but not human BPs. Finally, we identify putative cis-regulatory elements that may contribute to inter-species differences in EREG expression. Overall, our results suggest that species-specific expression of EPIREGULIN may contribute to increased neocortex size in primates by providing a pro-proliferative signal to BPs in the subventricular zone progenitor niche.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Cubillos, P., Ditzer, N., Kolodziejczyk, A., Schwenk, G., Hoffmann, J., Schütze, T. M., Derihaci, R. P., Birdir, C., Köllner, J. E. M., Petzold, A., Sarov, M., Martin, U., Long, K. R., Wimberger, P., Albert, M.. 2023-08-24. Primate-expressed EPIREGULIN promotes basal progenitor proliferation in the developing neocortex. https://doi.org/10.1101/2023.08.23.554446

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Hyaluronic acid dynamics are regulated by neural crest cells and NEDD4 in the developing cardiac outflow tract valves

The extracellular matrix (ECM) is essential for cardiac valve development, with hyaluronic acid (HA) playing a critical role in cardiac cushion formation. While HA is required for atrioventricular valve development, its role in semilunar valve formation remains poorly understood. The ubiquitin ligase NEDD4 is essential for cardiac outflow tract development, particularly within cardiac neural crest cells, however its role in semilunar valve development has been unexplored. Here, we demonstrate that neural crest-specific deletion of NEDD4 in mice disrupts outflow tract valve development, resulting in abnormal leaflet number and morphology. Analysis of valve ECM revealed a specific reduction in HA within the neural crest-derived valve mesenchyme, while other ECM components such as fibronectin and versican remained unaffected. In contrast, deletion of NEDD4 in endocardium-derived valve mesenchyme did not alter HA abundance. Using NEDD4-deficient neural crest cells, we further demonstrate a cell-autonomous requirement for NEDD4 in regulating HA abundance, with in vitro evidence supporting impaired HA synthesis rather than increased turnover of HA in the ECM. Our findings identify a previously unrecognised role for NEDD4 in regulating HA synthesis in cardiac neural crest cells, revealing a cell-type-specific mechanism governing semilunar valve development and highlighting distinct cellular requirements for ECM regulation across cardiac valve populations.

developmental biology↗

Endogenous Mechanical Reporters Encode the Global Mechanical Landscape of Morphogenesis

Developmental systems usually comprise multiple genetically programmed morphogenetic events within a mechanically continuous environment, yet how individual processes interact and contribute to the overall mechanical landscape remains unknown. Here, we introduce the concept of mechanical reporter: endogenous tissues function as in situ probes of the embedded mechanical landscape. We exemplified cephalic furrow (CF) migration as a mechanical reporter in gastrulating Drosophila. Using optogenetics and genetics, we revealed that CF displacement reflects the combined effect of both force and tissue mechanical properties. By incorporating condition-specific mechanical landscape into a continuum minimal-response model, we developed a framework to quantitatively predict the reporter dynamics. Using different genetic mutants, we successfully decoded changes in the mechanical landscape from CF dynamics in gastrulating Drosophila. Overall, we established a predictive framework that uses CF dynamics to infer changes in the global mechanical landscape. Beyond this, the concept of mechanical reporter provides a general strategy for systematically understanding and decoding complex mechanical environments in living systems.

developmental biology↗

Dissecting human embryonic patterning during organogenesis reveals a rostral midline progenitor population for mesoendoderm induction

Understanding how human organogenesis is accomplished via intricate spatiotemporal patterning of organ primordia requires spatial atlases at cellular resolution. However, existing human embryo spatial atlases are built using sequencing-based platforms such as Stereo-seq, which have limited spatial resolution and blurred anatomical boundaries, leading to misclassification across adjacent cells. Here, we integrate in situ imaging-based transcriptomics (Xenium) with transcriptome-wide spatial profiling (Visium-HD) of Carnegie stages 9-12 embryos to delineate the patterning of core embryonic tissues at single-cell resolution, including the brain, spinal cord, somites, neural crest, notochord, heart, and gut tube. A new finding enabled by spatial single-cell resolution is the identification of rostral midline progenitors (RMPs), a cell population co-expressing SOX2, TBXT, and OTX2. Transcriptionally, RMPs are distinct from both neuromesodermal progenitors (NMPs) and prechordal mesoderm, and in vivo clonal barcoding in mice indicates that RMPs share a common developmental origin with rostral neural ectoderm. To interrogate their functional significance, we leveraged our spatial transcriptome data to recapitulate RMP-like cells from human pluripotent stem cells and showed that these cells can induce epiblast-like cells to acquire mesendodermal and endodermal fates, while themselves adopting an ectodermal fate consistent with their in vivo counterparts. This work provides a 3D, stage-resolved molecular cell atlas of tissue patterning in human embryo that serves as a reference for in vitro models.

developmental biology↗