Résumé
A fundamental question in biology is how gene expression is regulated to give rise to a phenotype. However, transcriptional variability is rarely considered although it could influence the relationship between genotype and phenotype. It is known in unicellular organisms that gene expression is often noisy rather than uniform, and this has been proposed to be beneficial when environmental conditions are unpredictable. However, little is known about inter‐individual transcriptional variability in multicellular organisms. Using transcriptomic approaches, we analysed gene expression variability between individual
Arabidopsis thaliana
plants growing in identical conditions over a 24‐h time course. We identified hundreds of genes that exhibit high inter‐individual variability and found that many are involved in environmental responses, with different classes of genes variable between the day and night. We also identified factors that might facilitate gene expression variability, such as gene length, the number of transcription factors regulating the genes and the chromatin environment. These results shed new light on the impact of transcriptional variability in gene expression regulation in plants.
Synopsis
RNA‐seq on individual seedlings is used to detect inter‐individual gene expression variability in
Arabidopsis thaliana
. 9% of the transcriptome is identified as highly variable for at least one time point during the day/night cycle.
Two sets of highly variable genes were identified, either mainly variable during the day or night.
Highly variable genes tend to be involved in the response to the environment.
Highly variable genes tend to be shorter, to be targeted by a higher number of transcription factors and to be characterised by a “closed” chromatin environment.
Gene expression variability for individual genes of interest can be viewed on
https://jlgroup.shinyapps.io/AraNoisy/
.
Graphical Abstract
RNA‐seq on individual seedlings is used to detect inter‐individual gene expression variability in
Arabidopsis thaliana
. 9% of the transcriptome is identified as highly variable for at least one time point during the day/night cycle.