Immunoreactive ICD-1 is first detected as early as the two-cell stage and continues to be expressed widely throughout the lifespan of C. elegans. In post-embryonic development and adulthood, it is particularly highly expressed in the nerve ring and pre-anal ganglion, as well as in intestinal and germ cells of both hermaphrodites and males. The ventral nerve cord, epidermis and muscles contain smaller amounts of ICD-1, and expression in other cells (such as in the pharynx) is relatively weak.
Worms carrying the Ex-Y47H9 transgene had wild-type level broods (109 9 at 25C) in a spe-9(eb19) mutant background displayed no SPE-9 staining. Probably because of germline silencing.
EPG-9::GFP was ubiquitously expressed during embryogenesis. At postembryonic stages, epg-9 was widely expressed, including in pharyngeal muscles, neurons and intestinal cells.
GFP-tagged CED-9 is expressed broadly in pre-elongation embryos in a cytoplasmic lattice-like pattern, as has been reported for the CED-9 protein. CED-9::GFP is enriched in the gonadal region where germ cell apoptosis is observed.