ptps-1::GFP transgenics with the shorter upstream sequence resembled the
cat-4 expression pattern, with expression in some epidermal cells, and a few serotonergic neurons. The
ptps-1 reporters, however, were also observed in additional cells (including anterior intestine, VC4, 5 (weak) and HSN, plus lateral seam cells), and were not expressed in other epidermal cells or in all 5HT and DA neurons, suggesting these reporters may lack important positive or negative regulatory elements.