by Sanjeev Kulkarni
Econintersect: Jumping genes or Transposons which invaded the mammalian genome 100 million years ago “dramatically changed the way mammals reproduce — transforming the uterus in the ancestors of humans and other mammals from the production of eggs to a nurturing home for developing young, a new Yale University study has found.” The title of the Yale Daily Bulletin article sounds rather sensational: “Invasion of Genomic Parasites Triggered Modern Mammalian Pregnancy,” rivaling the impact of “Invasion of the Body Snatchers.” Transposons are DNA elements that can transpose from one place to another in a gene much like “cut” and paste operation in text editor.These jumping genes are are known to cause evolutionary changes and have also been implicated in cancer.
Transposons, or “jumping genes,” make up roughly half of the human genome. Geneticists previously estimated that they replicate and insert themselves into new locations roughly one in every 20 live births.
New results, published in the June 25, 2010 issue of Cell, suggest that every newborn is likely to have a new transposon somewhere in his or her genome.
“Now it looks like every person might have a new insertion somewhere,” says senior author Scott Devine, PhD, associate professor of medicine at the University of Maryland School of Medicine’s Institute for Genome Sciences. “This is an under-appreciated mechanism for continuing mutation of the human genome.”
The research was initiated at Emory University School of Medicine, where Devine was in the Department of Biochemistry. First author Rebecca Iskow, PhD (now a postdoctoral fellow at Brigham & Women’s Hospital in Boston) was a graduate student at Emory. Two other papers on human transposons appear in the same issue of Cell.