Making an Impression
Until about 15 years ago, scientists thought that the two copies of genes from both the mother and father are expressed equally. Since then, researchers have discovered that while such holds true for about 99.9 percent of the genome, there are about 100 genes where the mother's or the father's copy is permanently silenced. The expression of a trait being dependent on which parent from which the genetic material came is known as genetic imprinting. One of those currently researching genetic imprinting is Shirley Tilghman, Howard Hughes Medical Institute investigator and a professor in the department of molecular biology at Princeton University. At a recent joint meeting of the Association for Women in Science (AWIS) Philadelphia and central New Jersey chapters, Tilghman discussed her lab's work regarding the mechanism of gene silencing as well as the role it plays in mammalian development. She spoke about the...