Biogenesis and function of tRNA fragments during sperm maturation and fertilization in mammals

TLDR

Paternal diet influences offspring metabolic phenotypes through sperm small RNAs, but the underlying epigenetic mechanisms remain unclear. The study aims to elucidate how parental exposure to diet affects progeny, with implications for human diet‑induced metabolic disorders. Researchers injected tRNA fragments from high‑fat‑diet males into normal oocytes to assess their impact. The experiments revealed that altered paternal diet changes sperm tRNA fragment levels, induces metabolic disorders and gene expression changes in offspring, and that these fragments arise during sperm maturation. Chen et al.; Sharma et al.; Science, this issue p.

Abstract

Offspring affected by sperm small RNAs Paternal dietary conditions in mammals influence the metabolic phenotypes of offspring. Although prior work suggests the involvement of epigenetic pathways, the mechanisms remains unclear. Two studies now show that altered paternal diet affects the level of small RNAs in mouse sperm. Chen et al. injected sperm transfer RNA (tRNA) fragments from males that had been kept on a high-fat diet into normal oocytes. The progeny displayed metabolic disorders and concomitant alteration of genes in metabolic pathways. Sharma et al. observed the biogenesis and function of small tRNA-derived fragments during sperm maturation. Further understanding of the mechanisms by which progeny are affected by parental exposure may affect human diseases such as diet-induced metabolic disorders. Science , this issue p. 397 , p. 391