A transgene that includes only the
sid-1 promoter region fused to GFP (
sid-1 pro::GFP), is expressed in late embryos and continues to be detected in nearly all nonneuronal cell types through adulthood. The highest levels of GFP expression in the adult are in the cells and tissues in direct contact with the environment. These environment-exposed cells also show expression of a transgene construct in which GFP was fused to the COOH-terminus of full-length SID-1 (
sid-1::C-GFP). This construct was capable of rescuing
sid-1(
qt2) animals, suggesting that localization of this reporter is representative of SID-1 localization. Expression of SID-1::C-GFP was only seen in these environment exposed cells, perhaps because of the significantly lower expression of the translational reporter relative to the transcriptional reporter.