© GRACE RUSSELL
In 2005, Mike Skinner’s group at Washington State University published a disturbing observation: pregnant rats exposed to high levels of a commonly used fungicide had sons with low sperm counts as adults. When the males did succeed in impregnating a female, they bore sons who also had fewer sperm, and the gametes were less viable. The problem perpetuated through multiple generations, as Skinner’s lab observed the rats over several years.1
“We sat on [the results] for four years because it was a major observation, so we wanted to get as much on the mechanism as possible,” Skinner says. He and his colleagues found that altered DNA methylation patterns in the germ line were to blame.
To see if other environmental chemicals could have the same ...
