The
die-1 fosmid reporter is initially expressed very broadly throughout the developing embryo, including the hypodermis, where
die-1 acts to ensure ventral enclosure during gastrulation. Mirroring antibody staining, reporter expression of the fosmid reporter vanishes at approximately 460 min of embryonic development.
die-1 expression then reinitiates in many neurons,including both ASEL and ASER; shortly thereafter, expression in ASER becomes undetectable. ASEL-restricted expression is maintained throughout the embryonic, larval, and adult stages.
die-1 is also expressed in an asymmetric manner in the AWC olfactory neuron pair. Most adult animals show a strong bias of expression of
die-1 to either the left or right AWC neuron. This antisymmetric
die-1 expression is already evident in late embryos when the initial decision of AWC asymmetry control is made. ASEL-specific expression of
die-1can be observed before any AWC expression of
die-1 is observed. Expression of the
die-1 fosmid reporter correlates with the AWC OFF state.