By Akari Miki
Researchers at Duke University had pregnant C. elegans worms and divided them into two groups. They fed one group a bacterial broth, which is the normal diet for worms. Meanwhile, they fed the other group a diluted version of the broth, starving the worms. After the worms gave birth, the scientists took care of the offspring of both groups without food for eight days. As expected, the scientists observed that all starved larvae grew slower than well-nourished larvae. However, the offspring of deprived mothers still grew faster than those of healthy mothers. Even after the famine, the former recovered better as well.
Two possible explanations could account for these observations. First, the starvation may have reduced the rate of ovulation, resulting into more time for the eggs to grow before fertilization. Therefore, the eggs were bigger and had more nutrients. Another explanation is that the famine caused modifications in the mothers’ gene expression, and the offspring inherited them. Either way, the mothers’ experience triggered a mechanism that equipped the larvae for future starvation.
The possibility that the mother’s diet during pregnancy could impact her offspring’s metabolism has been observed in humans as well. When the incidence of type 2 diabetes in Western countries rose dramatically twenty years ago, some scientists proposed the thrifty phenotype hypothesis: pregnant mothers who did not eat enough had children with “thrifty” metabolisms. These children’s bodies used nutrients frugally and stored fats well, but when they were well-fed, this ability became harmful and led to diabetes. In contrast, the experiments with worms may suggest that these “thrifty” metabolisms obtained prenatally is beneficial for coping with starvation.
Duke University. (2016, October 28). Underfed worms program their babies to cope with famine: Findings are consistent with decades-old hypothesis for humans. ScienceDaily. Retrieved November 6, 2016 from www.sciencedaily.com/releases/2016/10/161028114012.htm