The smoking gun: Mothers could be harming their sons’ fertility
Researchers at the University of Newcastle in New South Wales, Australia looked at the male offspring of mice exposed to cigarette toxins during their time in the womb and lactation, until the male pups were weaned. Then they looked at the damage done to the DNA of cells involved in sperm production, and how well the sperm could swim. They also examined the offspring’s ability to have children of their own.
The study showed that the cigarette smoke exposure directly affected the stem cell population in the testes, resulting in fewer sperm which swam poorly and were abnormally shaped due to damage in the nuclei and mitochondria. These sperm had difficulty successfully binding to eggs as well.
Professor Eileen McLaughlin, Co-Director of the Priority Research Center in Chemical Biology, who led the team of researchers, said that "Consequently, when these pups reach adulthood they are sub-fertile or infertile."
And the damage to sperm DNA was permanent – even if the male offspring were not exposed to cigarette smoke again after weaning.
The team of researchers is now looking at the effects of cigarette smoke exposure in the sons and grandsons of the original male offspring. They are also looking at exposure effects on the fertility of female offspring, and will be examining subsequent generations of daughters and granddaughters in their future investigations.