Biology subjects

Adelmann, J. A.

Publications and source records attributed to Adelmann, J. A..

3 recordsLinked to original sources

bioRxiv2026

Determinants of the Transition Zone Width of Morphogen Readouts

In tissue patterning, cell fate boundaries often form transition zones with mixed or gradual fates rather than sharp demarcations. Traditionally, such zones in morphogen-driven systems were attributed to fluctuations in morphogen concentrations, especially at low molecule numbers. Here, we present experimental data from the mouse neural tube, the precursor of the central nervous system, which challenges this view. Contrary to expectations, we find that the transition zone width (TZW) does not increase with distance from the morphogen source. By combining experiments, theory, and computational modelling, we identify key factors shaping the TZW. Our findings suggest that cellular readout noise, rather than morphogen fluctuations, determine the TZW. The inferred variability in the parameters defining morphogen dynamics and cellular readout remains within previously reported physiological ranges. This discovery adds to earlier findings that morphogen gradients maintain higher-than-expected patterning precision over long distances, offering new insights into the robustness of developmental processes.

developmental biology↗

bioRxiv2022

Patterning precision under non-linear morphogen decay and molecular noise

Morphogen gradients can instruct cells about their position in a patterned tissue. Non-linear morphogen decay has been suggested to increase gradient precision by reducing the sensitivity to variability in the morphogen source. Here, we use cell-based simulations to quantitatively compare the positional error of gradients for linear and non-linear morphogen decay. While we confirm that non-linear decay reduces the positional error close to the source, the reduction is very small for physiological noise levels. Far from the source, the positional error is much larger for non-linear decay in tissues that pose a flux barrier to the morphogen at the boundary. In light of this new data, a physiological role of morphogen decay dynamics in patterning precision appears unlikely.

developmental biology↗

bioRxiv2022

Impact of cell size on morphogen gradient precision

Tissue patterning during embryonic development is remarkably precise. We numerically determine the impact of the cell diameter, gradient length, and the morphogen source on the variability of morphogen gradients and show that the positional error increases with the gradient length relative to the size of the morphogen source, and with the square root of the cell diameter and the readout position. We provide theoretical explanations for these relationships, and show that they enable high patterning precision over developmental time for readouts that scale with expanding tissue domains, as observed in the Drosophila wing disc. Our analysis suggests that epithelial tissues generally achieve higher patterning precision with small cross-sectional cell areas. An extensive survey of measured apical cell areas shows that they are indeed small in developing tissues that are patterned by morphogen gradients. Enhanced precision may thus have led to the emergence of pseudostratification in epithelia, a phenomenon for which the evolutionary benefit had so far remained elusive.

developmental biology↗