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Manning, C. S.

Publications and source records attributed to Manning, C. S..

5 recordsLinked to original sources

Domain-specific mechanisms of YAP1 variants in ocular coloboma revealed by in-vitro and organoid studies

The conserved transcriptional co-activator YAP1 is a central regulator of organ development and tissue homeostasis, integrating mechanical and biochemical cues to control cell proliferation and survival. YAP1 variants underlie a spectrum of congenital disorders, including autosomal dominant coloboma that can occur alone or with syndromic features. Despite this clinical significance, the functional role of YAP1 in human eye development, as well as the impact of disease-associated missense variants, remains poorly understood. Here we show YAP1 expression at the optic fissure in human embryos, a key structure involved in coloboma pathogenesis. We also identify a novel YAP1 variant in a proband with syndromic coloboma and investigate five previously reported coloboma-associated YAP1 variants. Using in silico prediction, cell-based assays, and fluorescence cross-correlation spectroscopy (FCCS) to directly quantify YAP1-TEAD binding, we demonstrate that the position of YAP1 missense variants dictates their functional changes. TEAD-binding domain mutations most strongly disrupted transcriptional activity in a luciferase assay, whereas all tested variants impaired induction of endogenous YAP1-TEAD target genes. Furthermore, mimicking reduced YAP1-TEAD binding using verteporfin small molecule in retinal organoids led to reduced progenitor proliferation and survival. These findings establish defective YAP1-dependent transcription as a mechanism driving congenital eye malformations and provide a framework for interpreting the pathogenicity of human YAP1 variants. More broadly, this study highlights the need for functional analyses to connect genetic variation with disease.

developmental biology↗

Oscillatory Co-expression of HES1 and HES5 Enables a Hybrid State in a Bistable Transcription Factor Regulatory Motif

Many cell fate decisions in the developing neural tube are directed by cross-repressive transcription factor (TF) motifs that generate bistability, enforcing expression of one dominant TF. However, evidence of hybrid states, where cells co-express opposing fate determinants, challenges this model. We hypothesised that oscillatory expression enables co-existence of cross-repressive TFs within single cells, allowing hybrid states in bistable motifs. To test this, we focused on HES1 and HES5, oscillatory, cross-repressive TFs that regulate neural progenitor maintenance and are expressed in adjacent dorsoventral domains in the developing spinal cord. Using live-cell imaging of fluorescent reporters and computational modelling, we show that HES1 and HES5 co-express and oscillate in-phase within single cells. Differences in protein stability result in distinct free-running periodicity, but co-expression results in entrainment and phase-locking. Modulating cross-repression strength and/or abundance shifts the system towards bistability and dominance of a single TF oscillator. Consistent with this, we observe progressive separation of the HES expression domains in vivo, through a decrease in oscillatory co-expression. Our findings provide a mechanism for hybrid states to emerge in a developmental bistable motif.

developmental biology↗

Inferring kinetic parameters of oscillatory gene regulation from single cell time series data

Gene expression dynamics, such as stochastic oscillations and aperiodic fluctuations, have been associated with cell fate changes in multiple contexts, including development and cancer. Single cell live imaging of protein expression with endogenous reporters is widely used to observe such gene expression dynamics. However, the experimental investigation of regulatory mechanisms underlying the observed dynamics is challenging, since these mechanisms include complex interactions of multiple processes, including transcription, translation, and protein degradation. Here, we present a Bayesian method to infer kinetic parameters of oscillatory gene expression regulation using an auto-negative feedback motif with delay. Specifically, we use a delay-adapted nonlinear Kalman filter within a Metropolis-adjusted Langevin algorithm to identify posterior probability distributions. Our method can be applied to time series data on gene expression from single cells and is able to infer multiple parameters simultaneously. We apply it to published data on murine neural progenitor cells and show that it outperforms alternative methods. We further analyse how parameter uncertainty depends on the duration and time resolution of an imaging experiment, to make experimental design recommendations. This work demonstrates the utility of parameter inference on time course data from single cells and enables new studies on cell fate changes and population heterogeneity.

developmental biology↗

A dynamic and spatially periodic micro-pattern of HES5 expression underlies the probability of neuronal differentiation in the mouse spinal cord

Ultradian oscillations of HES Transcription Factors (TFs) at the single cell level, enable cell state transitions. However, the tissue level organisation of HES5 dynamics in neurogenesis is unknown. Here, we analyse the expression of HES5 ex-vivo in the developing mouse ventral spinal cord and identify microclusters of 4-6 cells with positively correlated HES5 level and ultradian dynamics. These microclusters are spatially periodic along the dorsoventral axis and temporally dynamic, alternating between high and low expression with a supra-ultradian persistence time. We show that Notch signaling is required for temporal dynamics but not the spatial periodicity of HES5. Few Neurogenin-2 cells are observed per cluster, irrespective of high or low state, suggesting that the microcluster organization of HES5 enables the stable selection of differentiating cells. Computational modelling predicts that different cell coupling strengths underlie the HES5 spatial patterns and rate of differentiation, which is consistent with comparison between the motoneuron and interneuron progenitor domains. Our work shows a previously unrecognised spatiotemporal organisation of neurogenesis, emergent at the tissue level from the synthesis of single cell dynamics. SynopsisLive imaging of HES5 expression in the ventral mouse spinal cord together with computational modelling is used to identify and analyse spatially periodic HES5 micro-patterns that emerge from the synthesis of single cell dynamics. O_LIHES5 is expressed in spatially periodic microclusters along the dorsal-ventral axis in spinal cord that are dynamically maintained by Notch signalling. C_LIO_LIMicroclusters can arise, in part, from single cell oscillators that are synchronous and weakly coupled via Notch. C_LIO_LISpatial patterns are different between motorneuron and interneuron progenitor domains and the probability for progenitor differentiation is regulated by the coupling strength between cells. C_LIO_LINGN2 is also spatially periodic along the dorso-ventral axis and microclusters of HES5 may act to pick a single NGN2 high cell for differentiation. C_LI

developmental biology↗

Quantitative, real-time, single cell analysis in tissue reveals expression dynamics of neurogenesis

During embryogenesis cells make fate decisions within complex tissue environments. The levels and dynamics of transcription factor expression regulate these decisions. Here we use single cell live imaging of an endogenous HES5 reporter and absolute protein quantification to gain a dynamic view of neurogenesis in the embryonic mammalian spinal cord. We report that dividing neural progenitors show both aperiodic and periodic HES5 protein fluctuations. Mathematical modelling suggests that in progenitor cells the HES5 oscillator operates close to its bifurcation boundary where stochastic conversions between dynamics are possible. HES5 expression becomes more frequently periodic as cells transition to differentiation which, coupled with an overall decline in HES5 expression, creates a transient period of oscillations with higher fold expression change. This increases the decoding capacity of HES5 oscillations and correlates with interneuron versus motor neuron cell fate. Thus, HES5 undergoes complex changes in gene expression dynamics as cells differentiate.

developmental biology↗