Stochastic gene expression, an ordinary part of multicellular life

Stochasticity is an important feature of genes, allowing for variability in their abundance and activity prior to ‘fine-tuning’ at later periods of development. Kong et al. describe this feature in auxin responsive genes, attributing their ‘stochastic’- or inherently random expression – as an internal feature of cells, allowing for later canalization (development of robust expression) to inform points of organ outgrowth. Using a coordinate system, they showed that the variability of DR5 (an auxin responsive gene commonly used as a marker for auxin activity) expression was high at early stages, organizing later to form robust regions of signaling points in the flower primordia where the sepals would arise. This high variability at early stages is due to intrinsic molecular noise at a cellular level, across a limited number of cells. The authors found that the development of robust signaling regions where the sepals appear was due to averaging of this stochastic expression across a wider cell area at later stages of development. Other auxin responsive genes, however, were found to act differently, with similar levels of stochasticity but decreased noise in precise locations, indicating self-regulation. Given the differences between auxin responsive genes, this research highlights the opportunity to investigate promoter architecture as a means of precise genetic engineering, whilst also providing insight into how plants manage to balance complex, messy processes with coordinated development of structures. (Summary by Kes Maio) Nature Comms. 10.1038/s41467-025-59943-4