Search bioRxiv⌕ Search

Biology subjects

Wind, M.

Publications and source records attributed to Wind, M..

4 recordsLinked to original sources

Early anteroposterior regionalisation of human neural crest is shaped by a pro-mesodermal factor

The neural crest (NC) is an important multipotent embryonic cell population and its impaired specification leads to various developmental defects, often in an anteroposterior (A-P) axial level-specific manner. The mechanisms underlying the correct A-P regionalisation of human NC cells remain elusive. Recent studies have indicated that trunk NC cells, the presumed precursors of the childhood tumour neuroblastoma, are derived from neuromesodermal-potent progenitors of the postcranial body (NMPs). Here we employ human embryonic stem cell differentiation to define how NMP-derived NC cells acquire a posterior axial identity. We show that TBXT, a pro-mesodermal transcription factor, mediates early posterior NC regionalisation together with WNT signalling effectors. This occurs by TBXT-driven chromatin remodelling via its binding in key enhancers within HOX gene clusters and other posterior regulator-associated loci. In contrast, posteriorisation of NMP-derived spinal cord cells is TBXT/WNT-independent and takes place under the influence of FGF signalling. Our work reveals a previously unknown role of TBXT in influencing posterior NC fate and points to the existence of temporally discrete, cell type-dependent modes of posterior axial identity control.

developmental biology↗

A realistic touch-transfer method reveals low risk of transmission for SARS-CoV-2 by contaminated coins and bank notes

The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a significant threat to global health. While respiratory aerosols or droplets are considered as the main route of human-to-human transmission, secretions expelled by infected individuals can also contaminate surfaces and objects, potentially creating the risk of fomite-based transmission. Consequently, frequently touched objects such as paper currency and coins have been suspected as a potential transmission vehicle. To assess the risk of SARS-CoV-2 transmission by banknotes and coins, we examined the stability of SARS-CoV-2 and bovine coronavirus (BCoV), as surrogate with lower biosafety restrictions, on these different means of payment and developed a touch transfer method to examine transfer efficiency from contaminated surfaces to skin. Although we observed prolonged virus stability, our results, including a novel touch transfer method, indicate that the transmission of SARS-CoV-2 via contaminated coins and banknotes is unlikely and requires high viral loads and a timely order of specific events.

microbiology↗

Defining the signalling determinants of a posterior ventral spinal cord identity in human neuromesodermal progenitor derivatives

The anteroposterior axial identity of motor neurons (MNs) determines their functionality and vulnerability to neurodegeneration. Thus it is a critical parameter in the design of strategies aiming to produce MNs from human pluripotent stem cells (hPSCs) for regenerative medicine and disease modelling applications. However, the in vitro generation of posterior spinal cord MNs has been challenging. Although the induction of cells resembling neuromesodermal progenitors (NMPs), the bona fide precursors of the mammalian spinal cord, offers a promising solution, the progressive specification of posterior MNs from these cells is not well-defined. Here we determine the signals guiding the transition of human NMP-like cells toward posterior ventral spinal cord neurectoderm. We show that combined WNT-FGF activities drive a posterior dorsal early neural state while suppression of TGFβ-BMP signalling pathways, combined with SHH stimulation, promotes a ventral identity. Based on these results, we define an optimised protocol for the generation of posterior MNs that can efficiently integrate within the neural tube of chick embryos. We expect that our findings will facilitate the functional comparison of hPSC-derived spinal cord cells of distinct axial identities.Competing Interest StatementThe authors have declared no competing interest.View Full Text

developmental biology↗

Human axial progenitors generate trunk neural crest cells

The neural crest (NC) is a multipotent embryonic cell population generating distinct cell types in an axial position-dependent manner. The production of NC cells from human pluripotent stem cells (hPSCs) is a valuable approach to study human NC biology. However, the origin of human trunk NC remains undefined and therefore current in vitro differentiation strategies induce only a modest yield of trunk NC cells. Here we show that hPSC-derived axial progenitors, the posteriorly-located drivers of embryonic axis elongation, give rise to trunk NC cells and their derivatives. Moreover, we define the molecular signatures associated with the emergence of human NC cells of distinct axial identities in vitro. Collectively, our findings indicate that there are two routes toward a human post-cranial NC state: the birth of cardiac and vagal NC is facilitated by retinoic acid-induced posteriorisation of an anterior precursor whereas trunk NC arises within a pool of posterior axial progenitors.

developmental biology↗