The expression and projection patterns and body fluid secretion function of DH44 and DH31-expressing cells and their receptors in adult Drosophila. DH44 + PI neurons project along the esophagus to innervate the crop. DH44-R1 and DH31 receptors are expressed in CRZ neurons located in the lateral part of the brain. DH31-expressing enteroendocrine (DH31 + EE) cells are located around the posterior midgut. DH44-R2 and DH31-R are expressed in the midgut and the principal cells of the Malpighian tubules. DH44-R2 and DH31-R are expressed on the principal cells of the Malpighian tubules, where they work together to increase the concentration of cAMP, activating V-type ATPase and playing a role in body fluid secretion. DH44 + PI, diuretic hormone 44 expressing neurons located in the pars intercerebralis of the brain; DH44 + VNC, diuretic hormone 44 expressing neurons located in the ventral nerve cord; DH31, diuretic hormone 31 expressing cells; DH44-R1, diuretic hormone 44 receptor 1 expressing neurons; DH44-R2, diuretic hormone 44 receptor 2 expressing cells; DH31, diuretic hormone 31 expressing cells; DH31-R, diuretic hormone 31 receptor-expressing cells; CRZ, corazonin; PV, proventriculus; CC, corpora cardiaca; HCG, hypocerebral ganglion; VNC, ventral nerve cord; cAMP, cyclic adenosine monophosphate.
