CCK and Anxiety: In order to compare the expression patterns of anxiety and appetite related genes of WT, npy2r+/+ and npy2r+/− medaka, we measured the mRNA expression levels of genes associated with anxiety behavior (th1, th2, gr1, gr2, mr), appetitive genes (agrp, npy), and anorexigenic factors (pomc, cck) by qRT-PCR.