<i>grk-2</i> acts in parallel to <i>pdfr-1</i> and <i>tph-1</i> to control exploration.

(A) grk-2(gk268) and pdfr-1(ok3425) mutants have exploration defects. The double mutant grk-2(gk268); pdfr-1(ok3425) has a stronger phenotype than the single mutants suggesting that these genes act in parallel to control exploration behavior. Shown is the number of squares (out of 50) single animals covered in ~20 h. (****, Pgrk-2(gk268) mutant animals explore less and tph-1(mg280) more than WT animals. The double mutant tph-1(mg280); grk-2(gk268) has an intermediate phenotype suggesting that these genes act in parallel pathways to control exploration behavior. (****, P (PDF)