PT  - JOURNAL ARTICLE
AU  - Marcus D. Kilwein
AU  - Matthew R. Johnson
AU  - Jonathon M. Thomalla
AU  - Anthony Mahowald
AU  - Michael A. Welte
TI  - Drosophila embryos spatially sort their nutrient stores to facilitate their utilization
AID  - 10.1101/2022.05.20.492771
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.05.20.492771
4099  - http://biorxiv.org/content/early/2022/05/20/2022.05.20.492771.1.short
4100  - http://biorxiv.org/content/early/2022/05/20/2022.05.20.492771.1.full
AB  - Animal embryos are provisioned by their mothers with a diverse nutrient supply critical for development. In Drosophila, the three most abundant nutrients (triglycerides, proteins, and glycogen) are sequestered in distinct storage structures, lipid droplets (LDs), yolk vesicles (YVs) and glycogen granules (GGs). Using transmission electron microscopy as well as live and fixed-sample fluorescence imaging, we find that all three storage structures are dispersed throughout the egg but are then spatially allocated to distinct tissues by gastrulation: LDs largely to the peripheral epithelium, YVs and GGs to the central yolk cell. To confound the embryo’s ability to sort its nutrients, we employ mutants in Jabba and Mauve to generate LD:GG or LD:YV compound structures. In these mutants, LDs are missorted to the yolk cell and their turnover is delayed. Our observations demonstrate dramatic spatial nutrient sorting in early embryos and provide the first evidence for its functional importance.Competing Interest StatementThe authors have declared no competing interest.