Selenium's Role in Infertility Explained

Many proteins lead multiple lives, depending on environmental conditions or on the presence of particular partners. It's rare, however, for a protein to change its stripes completely, acting as a soluble enzyme under some circumstances and an insoluble structural component under others. But that's what new research suggests for a particular selenium-containing protein of sperm—a discovery that may help explain the long-standing mystery of why selenium deficiency in lab and domestic animals leads to male sterility.