MOLECULAR-CLONING OF 3 DISTINCT CDNAS, EACH ENCODING A DIFFERENT ADIPOKINETIC HORMONE PRECURSOR, OF THE MIGRATORY LOCUST, LOCUSTA-MIGRATORIA - DIFFERENTIAL EXPRESSION OF THE DISTINCT ADIPOKINETIC HORMONE PRECURSOR GENES DURING FLIGHT ACTIVITY

Three distinct cDNAs encoding the preproadipokinetic hormones I, II, a nd III (prepro AKH I, II, and III), respectively, of Locusta migratori a have been isolated and sequenced. The three L. migratoria AKH precur sors have an overall architecture similar to that of other precursors of the AKH/red pigment-concentrating hormone (RPCH) family identified so far. The AKH I and LT precursors of L. migratoria are highly homolo gous to the Schistocerca gregaria and Schistocerca nitans AKH precurso rs. Although the L. migratoria AKH LII precursor appears to be the lea st homologous to the Manduca sexta, Drosophila melanogaster, and Carci nus maenas AKH/RPCH precursors, we favor the opinion that the L. migra toria AKH III precursor is evolutionary more related to the M. sexta, D. melanogaster, and C. maenas AKH/RPCH precursors than to the AKH I a nd II precursors of S. gregaria, S. nitans, or L. migratoria. In situ hybridization showed signals for the different AKH mRNAs to be co-loca lized in cell bodies of the glandular lobes of the corpora cardiaca. N orthern blot analysis revealed the presence of single mRNA species enc oding the AKH I precursor (similar to 570 bases), AKH II precursor (si milar to 600 bases), and AHA III precursor (similar to 670 bases), res pectively. Interestingly, flight activity increased steady-state level s of the AKH I and II mRNAs (similar to 2.0 times each) and the AHA II I mRNA (similar to 4.2 times) in the corpora cardiaca.