Drosophila Hedgehog can act as a morphogen in the absence of regulated Ci processing

Abstract

a linear gradient of Hh-stimulated degradation, allowing derivation of a spatial profile of inhibition of processing of normal C-155 by Hh. The processing-resistant Ci variants were also significantly activated in the absence of Hh by elimination of Cos2, acting through association with the CORD domain of Ci, or PKA, revealing separate inhibitory roles of these two components in addition to their well-established roles in promoting Ci-155 processing.

Cascade versus Mechanism: The Diversity of Causal Structure in Science

“…An important feature of causal triggers is that they have significant control over their effects, often producing them with a high likelihood. Due to this, scientists claim that these causes have a "strong" influence and "kick-start" the causal process (Paine 1980;Little et al 2020). This leads causal triggers to take on significant causal responsibility-they are viewed as having more explanatory power and as being "better predictors" of the downstream outcome than other causes (Herren and McMahon 2018).…”