Ageless athlete may not be far offPenn's research into a synthetic gene has wide implications for sports.By Frank FitzpatrickInquirer Staff WriterYou know all those steroid-laced sluggers, blood-doped swimmers, and hormonally enhanced weightlifters who people worry are ruining sports?They're just minor-league fears.The real nightmare is lurking inside tiny cages in a University of Pennsylvania basement.There, genetically engineered mice and rats, some of them the equivalent of 80-year-old humans, display rippling, well-toned muscles that neither aging nor a lack of exercise can diminish.Injected only once with a synthetic gene created by researchers in Penn's physiology department, these ripped rodents are as much...