Dicarbonyl/L-xylulose reductase (DCXR) producing xylitol regulates egg retention through osmolality control in .

To support life, the osmolality of the cellular fluid is tightly regulated by various means, including osmolyte control. Dicarbonyl/L-xylulose reductase (DCXR) is a highly conserved enzyme reducing L-xylulose to xylitol, which serves as an effective osmolyte in various mammalian and human tissues such as lung epithelium, sperm, and lens. DHS-21 is the only DCXR ortholog in , and DCXR null mutant worms accumulate eggs in the uterus.