A HORMONE FROM THE UTERUS OF THE TSETSE-FLY, GLOSSINA-MORSITANS, STIMULATES PARTURITION AND ABORTION

Unlike most insects, the tsetse female gives birth to a single, fully grown larva at the culmination of each pregnancy cycle, The expulsion of the larva is regulated by a hormone present in rich abundance withi n the female's uterus, The hormone elicits parturition when injected i nto neck-ligated females at late stages of pregnancy and abortion when injected at earlier stages, We refer to this highly active material ( 0.043 uterus equivalents stimulates parturition in 50% of the females) as parturition hormone, Injection of the active extract, which appear s to be a peptide or small protein, initiates the series of blood pres sure pulsations and uterine contractions normally associated with part urition, The discovery that a uterus extract from the flesh fly also e licits parturition in tsetse suggests that this hormone may be widely distributed in insects. (C) 1997 Elsevier Science Ltd. All rights rese rved.