New Model Proposes Growth Rate-Dependent Feedback Controls Organ Size Without Direct Size Sensing
Researchers have proposed a new mathematical model suggesting that organs determine their final size by monitoring and responding to their own growth rate, rather than directly sensing how large they are. The study uses Drosophila (fruit fly) imaginal discs — the standard model system for studying organ size — to test and support this framework. If validated, the model could reshape understanding of a longstanding open question in developmental biology: how organs reliably reach a consistent, species-typical size.
A new preprint posted to bioRxiv presents a model for organ size determination based on growth rate-dependent negative feedback, challenging the assumption that tissues must directly sense their own size to stop growing at the right time. Using Drosophila wing imaginal discs — a well-established experimental system in developmental biology — the authors argue that feedback triggered by the rate of growth, rather than absolute size, is sufficient to explain how organs reliably reach their final dimensions. A key prediction of the model is that size alterations imposed before the active growth period are not corrected, whereas perturbations to growth rate at the start of the growth period do trigger compensatory, size-restoring responses. This distinction offers a testable framework that could reconcile conflicting experimental observations in the field. The intrinsic mechanism of organ size control has remained elusive despite decades of genetic, cellular, and mechanical studies, making this a significant conceptual contribution, though as a preprint it has not yet undergone peer review.
What's missing
As a preprint, this work has not yet been peer-reviewed. The study does not detail the specific molecular or signaling pathways that would implement the proposed growth rate-sensing feedback mechanism in vivo, leaving the biochemical basis of the model unspecified. It is also unclear how well the model generalizes beyond Drosophila imaginal discs to vertebrate organ systems.
What different sources said
- bioRxivCenter
Determining organ size through growth rate dependent negative feedback without sensing size.
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