New Model Proposes Growth Rate-Dependent Feedback Controls Organ Size Without Direct Size Sensing
Researchers propose a new mechanism for how organs reach their proper size: through growth rate-dependent negative feedback rather than direct size sensing. The model, tested in Drosophila wing imaginal discs, suggests that the system corrects for changes in growth rate during early growth periods but not for pre-existing size differences. This challenges decades of assumptions about how organisms determine and maintain organ dimensions.
A new study published on bioRxiv presents an alternative model for organ size determination, proposing that organs regulate their final size through growth rate-dependent negative feedback mechanisms rather than by directly sensing their own dimensions. Using Drosophila imaginal discs—a standard model system for studying organ growth—the researchers demonstrate that the system responds to alterations in growth rate during the initial growth phase by triggering size-restoring feedback. Notably, the model indicates that size differences present before the growth period begins are not corrected for, suggesting the feedback mechanism operates on growth dynamics rather than absolute size measurements. This finding potentially resolves a long-standing puzzle in developmental biology about how organs achieve consistent sizes despite variable starting conditions.
What's missing
The study's own limitations and caveats are not detailed in the provided abstract, such as the scope of applicability beyond Drosophila, experimental sample sizes, or whether the model has been validated in other organ systems or organisms.
What different sources said
- bioRxivCenter
Determining organ size through growth rate dependent negative feedback without sensing size.
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