Egg maturation and ecdysiotropic activity in extracts of mosquito (Aedes aegypti) heads.
Blood-fed, decapitated female Aedes aegypti mosquitoes matured eggs when injected with an extract of heads, but non-blood-fed females did not. The response to head extract was optimal when the head was allowed to remain for 2 hr after feeding. A dose response to injected egg development neurosecretory hormone (EDNH) was observed in vivo that was similar to in vitro dose responses previously reported. Blood-fed decapitated females responded equally well to boiled or unboiled head extract. When blood-fed decapitated females were injected with head extract, ecdysteroid levels increased. Partial purification of head extract using high-pressure liquid chromatography yielded a fraction at 34% acetonitrile that showed egg maturation activity in vivo when injected into blood-fed decapitated females, and ecdysiotropic activity when incubated in vitro with ovaries. In addition, a fraction at 30% acetonitrile was found that showed activity in vivo but not in vitro and may be a precursor. Occasionally, the fraction at 37% acetonitrile showed activity in the in vitro assay but had little activity in vivo and may be a metabolite. These results suggest that the same hormone was being assayed in vivo and in vitro and is EDNH.
D000330:Aedes / Q000502:physiology*; D000818:Animals; D004440:Ecdysone / Q000032:analysis; D026461:Ecdysteroids; D005260:Female; D006257:Head; D007447:Invertebrate Hormones / Q000032:analysis / Q000502:physiology*; D010053:Ovary / Q000187:drug effects / Q000502:physiology*; D010063:Ovum / Q000187:drug effects / Q000502:physiology; D011863:Radioimmunoassay; D014020:Tissue Extracts / Q000494:pharmacology*
D026461:Ecdysteroids; D007447:Invertebrate Hormones; D014020:Tissue Extracts; D004440:Ecdysone