This 2015 roundworm study showed one possible way that epigenetic DNA changes could pass from one generation to the next generation:
- The researchers caused nerve cells to transmit double-stranded RNA to germline cells.
- The RNA changed the germline cells, and
- The changes were passed down to the next 25 generations.
This was a new direction that had several known limitations ahead. The researchers didn’t show that this transmission mechanism worked in nature. Also, more complex species don’t retain most epigenetic changes between generations.
- Treating the father’s symptoms of an inherited disease can epigenetically treat the son provided evidence of one mechanism in a rodent study, and
- Are stress-induced epigenetic changes to DNA inherited across generations? showed another transmission method.
http://www.pnas.org/content/112/7/2133.full “Double-stranded RNA made in C. elegans neurons can enter the germline and cause transgenerational gene silencing”