Endogenous Expression of the E3 Ubiquitin Ligase EEL-1 in Caenorhabditis elegans

The conserved HECT E3 ubiquitin ligase EEL-1 (human HUWE1) coordinates DNA damage-induced apoptosis, neuronal architecture, and embryogenesis in Caenorhabditis elegans. However, its endogenous spatiotemporal distribution remains uncharacterized. Using CRISPR/Cas9 genome editing, we generated an endogenous EEL-1::GFP knock-in strain. Confocal microscopy reveals nuclear-enriched fluorescence across the germline syncytium, oocytes, and early embryonic blastomeres, alongside prominent expression in head neurons and the pharynx. These localization patterns visually substantiate genetic requirements for EEL-1 in checkpoint apoptosis, transcriptional regulation, and neurodevelopment, establishing an in vivo anatomical framework to identify conserved HUWE1/EEL-1 degradation substrates 11/10/2026 -Open Access