Do you take after your dad's RNA?

"Yin's team analyzed the molecules inside the exercising rodents' sperm and found tiny bits of RNA-dubbed microRNAs-that were present in higher amounts than in the sperm of their idle littermates. When the scientists injected those molecules into unrelated embryos, they got animals just as fit as those that were born to exercising fathers."

"Over the past two decades, studies in mice have detected microRNAs and other types of RNA fragments that surge and wane inside sperm cells in response to not just exercise or sloth but also fatty or sugary diets, daily stress, childhood trauma, heavy drinking and exposure to pesticides and other hazards."

"In step with these changes, researchers have documented developmental and metabolic changes and differing rates of depression in the males' offspring. And while it's difficult to study the effect in people, researchers also have documented fluctuations in RNA fragments in the sperm of men who do or don't exercise, smoke or e"

"The secret to their speediness isn't carried in their genes-the animals come from the same genetic stock as a group of control mice. And they haven't received any special training. Instead, their fitness seems to stem from their father's exercise habits before they were even conceived."

Mice born from fathers that exercised before conception show greater running endurance and lower lactic acid buildup than control littermates. The offspring share the same genetic stock and receive no special training, indicating the effect comes from paternal experience rather than inherited DNA sequence. Analysis of sperm from exercising males reveals higher levels of microRNAs. Introducing these microRNAs into unrelated embryos produces offspring with fitness comparable to those from exercising fathers. Across many mouse studies, sperm RNA fragments shift in response to exercise, diet, stress, trauma, alcohol use, and pesticide exposure. These molecular changes correlate with developmental and metabolic differences and altered depression rates in male offspring. Human studies also report sperm RNA fragment differences linked to exercise and smoking.

Read at Ars Technica