Researchers at Brown University have found that male fruit flies can express a protein that lets them upregulate their X chromosome in order to compensate for "genetic shortcomings," reports LiveScience's Jennifer Welsh. In order for male Drosophila to survive, the researchers write in their study published in Nature, they have to regulate the imbalance created by having only one X chromosome, and they do it by expressing the male-specific lethal protein which doubles the gene expression on the X chromosome, Welsh says. "The finding, if it holds up in humans, could help scientists understand the basis of some X chromosome-linked diseases, which are much more frequent in men because they only have one copy of each X chromosome gene," she adds.