A study suggests that small molecules in sperm called "tRNA-derived small RNAs" (tsRNAs) may be involved in transmitting effects of maternal obesity across generations. Recent work has shown that maternal obesity in mice is associated with physiological and behavioral changes that affect up to three generations of offspring. Daria Peleg-Raibstein and colleagues found that levels of certain tsRNAs were significantly higher in sperm of males born to mothers fed a high-fat diet (HFD), compared with males from mothers fed a normal diet. The authors extracted sperm tsRNA from the offspring of HFD-fed and normal diet-fed mothers and injected it into normal mouse zygotes to generate HFD-tsRNA and control offspring, respectively. Compared with controls, offspring born through the HFD-tsRNA injection showed increased addictive-like behaviors, such as increased preference for and consumption of HFD, sucrose, and alcohol, and enhanced sensitivity to amphetamines. Additionally, HFD-tsRNA offspring developed obesity and impaired insulin sensitivity compared with controls, especially when given free access to HFD and sucrose. HFD-tsRNAs targeted several key genes involved in addiction and obesity, and both the HFD sperm donors and HFD-tsRNA offspring showed altered expression of these genes, compared with controls, in brain regions involved in reward. According to the authors, the results suggest that sperm tsRNAs contribute to the transgenerational transmission of addictive and obesity-causing traits induced by maternal HFD.
Article #18-20810: "Maternal overnutrition programs hedonic and metabolic phenotypes across generations through sperm tsRNAs," by Gitalee Sarker et al.
MEDIA CONTACT: Daria Peleg-Raibstein, ETH Zurich, SWITZERLAND; tel: +41-446557350; e-mail: daria-peleg@ethz.ch
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Proceedings of the National Academy of Sciences