ALLATOSTATINS IN THE HEMOLYMPH OF DIPLOPTERA-PUNCTATA AND THEIR EFFECT IN-VIVO

Adult female Diploptera punctata haemolymph extract was separated by h igh-pressure liquid chromatography, and fractions that coeluted with a llatostatins I-V inhibited juvenile hormone synthesis by corpora allat a in vitro. Saline extract of haemolymph was heated to 100 degrees C, purified by reverse-phase C-18 solid phase extraction and then by high -pressure liquid chromatography separation on a reverse-phase C-18 col umn. Fractions corresponding to the elution times of allatostatins I-I V and allatostatin V were collected from each chromatographic separati on. Similar fractions were combined and reapplied to the same column. Inhibition was found in fractions with elution times corresponding to allatostatins IV, I-III and V. Percent inhibition in these fractions f rom haemolymph of 13-14-day mated females was 44 +/- 7 57 +/- 3 and 55 +/- 3 and 70 +/- 3, respectively (similar to 1.2ml haemolymph equival ents/CA). To determine whether allatostatins in the haemolymph can inh ibit the corpora allata, D. punctata allatostatins I and V and a relat ed active peptide, callatostatin 5 from Calliphora vomitoria, were inj ected into mated females on days 1-3 after ecdysis at 12 h intervals. As controls, luteinizing hormone releasing hormone, truncated allatost atin I (N-terminal 1-7, unamidated) and water were injected. On day 4, length of basal oocytes and/or juvenile hormone synthesis by the corp ora allata were significantly lower in animals injected with active al latostatins compared with water-injected controls, whereas, they were not affected by injection of inactive peptides.