Utilization of a particle gun DNA introduction system for the analysis of cis -regulatory elements controlling the spatial expression pattern of the arylsulfatase gene ( HpArs ) in sea urchin embryos

. We applied a particle gun method to introduce DNA into fertilized sea urchin eggs for the analysis of cis -regulatory elements responsible for spatial gene expression during development. We introduced HpArs (sea urchin arylsulfatase gene) –GFP and HpArs–LacZ fusion constructs into the fertilized eggs and obtained high expression levels of the fusion genes. Using this assay system, we demonstrated that a fragment of HpArs (–3,484 to +4,636) is sufficient for aboral ectoderm-specific expression, and that the region in the first intron from +406 to +1,993 contains the control elements responsible for the repression of the HpArs promoter activity in secondary mesenchyme cells.