So-called junk DNA plays critical role in mammalian development

Despite the prevalent view that some 98% of our genome is junk DNA, new research shows that one piece of junk DNA -- the promoter of a virus-based transposon -- plays a critical role in cell proliferation and timing of embryo implantation in mice. The group found virus-based promoters linked to genes involved in development in other mammals, including humans, suggesting that transposons have been broadly repurposed for important regulatory roles.