Metabolic hubs in reproduction: The regulatory network of lipid droplets in gamete and embryo physiology (Review)

Lipid droplets (LDs) are dynamic organelles that extend beyond lipid storage to regulate diverse aspects of reproductive physiology. In both mammals and Caenorhabditis elegans, LDs support gamete maturation, fertilization, embryogenesis and steroidogenesis by modulating lipid mobilization, signaling pathways, protein quality control and hormone production. The present review highlights the roles of LDs in oocytes, sperm, Sertoli and granulosa cells, embryonic stem cells and early embryos. Key regulatory molecules, including perilipins, adipose triglyceride lipase, Hormone‑Sensitive Lipase (HSL), Diacylglycerol O‑acyltransferases and seipin, as well as lipophagy, are discussed in the context of reproductive cell function. C. elegans demonstrates conserved genetic pathways linking LD metabolism with gamete quality and embryonic viability. The present review aimed to discuss emerging technologies such as lipidomics, high‑resolution imaging, Clustered Regularly Interspaced Short Palindromic Repeats screening and single‑cell sequencing that enable deeper investigation into LD dynamics. Finally, the present review aimed to examine how LD dysfunction contributes to reproductive disorders including infertility, polycystic ovary syndrome and metabolic syndrome. Understanding LD biology offers promising avenues for improving reproductive health and gamete and embryonic developmental potential.