Age-Associated Increases In Inter-Individual Gene Expression Variability Across Human Tissues
As we age, our bodies undergo many changes, and scientists are constantly working to understand the underlying biological processes. One key area of study is gene expression, which is essentially how our genes “turn on” or “off” to produce proteins and carry out cellular functions. Traditionally, research has focused on how the average level of gene activity changes with age across a population. However, a recent study sheds light on another important aspect: how the variability in gene activity between different individuals changes as they get older.
This research introduces a new way to look at gene activity, focusing on what are called “differentially variable genes.” Instead of just seeing if a gene becomes more or less active on average, this approach examines if its activity becomes more or less consistent among different people of the same age. By analyzing data from nearly a thousand individuals across 30 different tissue types, the study found that age-related increases in this inter-individual variability account for a significant portion of the overall differences in gene activity observed between people in the same tissue.
Interestingly, the genes that show increased variability with age affect different biological pathways compared to those genes that simply change their average expression levels. This suggests that aging involves more than just a uniform shift in gene activity; it also introduces a greater degree of individuality in how our genes function. Furthermore, the study revealed that this increased variability isn’t just random noise; it’s influenced by the complex networks that regulate gene activity. These findings suggest that the aging process involves both predictable, coordinated changes and an increase in the unpredictable, stochastic (random) nature of gene expression across individuals and even within cells.
Source: link to paper