Though our DNA is fixed, the expression of genes is not. Some genes stay dormant for our entire lives, some are always ‘on’, others are active at some points, and inactive at others. We are only at the beginning of understanding what causes this ‘toggling’ of our genes, but a recent study suggests gender may be an important factor.
A new technique developed at Stamford University School of Medicine, allows researchers to work with real cells in real time, gathered from a living person, rather than using cells grown from other cells in a lab.
In a study published July 29 in the new journal Cell Systems “Individuality and Variation of Personal Regulomes in Primary Human T Cells”, lead investigator Howard Chang describes how his team took ordinary blood samples from 12 healthy volunteers, and isolated their T cells, an important component of the immune system. They measured the way certain genes in the cells are switched on and off, and how that measure varied from individual to individual. Chang’s team also looked at how much change occurred at different times in the same volunteers.
They found that the single greatest predictor for certain genes’ tendency to turn on and off was the sex of the person.
Across the 12 volunteers, 7 percent of the genes were switched on in different patterns from person to person. For each person, these patterns persisted over time, like a unique fingerprint. “But the single greatest predictor for genes’ tendency to turn on and off was the sex of the person. In terms of significance,” said Chang, “sex was far more important than all the other things we looked at, perhaps even combined.”
When the team measured gene activity levels from 30 of the top 500 genes the researchers expected would show gender-influenced activity, they found that 20 of the 30 genes showed significant differential activity between men and women. Research like this may help to explain the much higher incidence in women of autoimmune diseases such as scleroderma, lupus and rheumatoid arthritis.