Cloning and expression analysis of a 5HT7-like serotonin receptor cDNA from mosquito Aedes aegypti female excretory and respiratory systems

In the mosquito Aedes aegypti, 5-HT changes the endogenous rhythm of contra ctions in the female hindgut and increases fluid secretion in the larval Ma lpighian tubule. The role of 5-HT as a diuretic hormone in adults has been questioned. We cloned a cDNA encoding a serotonin receptor from a female A. aegypti Malpighian tubule library that is similar to the 5-HT7 receptor fr om Drosophila melanogaster. The transcript was localized in the tracheolar cells associated with the female Malpighian tubules but no signal was detec table in the tubule epithelium. Immunohistochemistry with specific antibodi es confirmed the receptor expression in tracheolar cells and hindgut, and w estern blots of these tissues showed the expected 50 kDa band. The results suggest a role for serotonin in respiration and that this receptor may coor dinate the tubule-hindgut response to serotonin during diuresis.