Molecular characterization and distribution of CYCLE protein from Athalia rosae.

cDNA encoding CYCLE (CYC) from the coleseed sawfly, Athalia rosae (Hymenoptera, Symphyta), was amplified by PCR. This is a first determination of hymenopteran CYC structure. ArCYC had an overall identity of 66% with CYC of Anopheles gambiae and ca. 60% of Drosophila melanogaster. Structural investigation revealed that ArCYC contained characteristic motifs of: bHLH, PAS A, PAS B, PAC and BCTR. Detailed analysis indicated high conservation of these regions among insects. Northern blot analysis showed that the mRNA of ca. 3 kb was transcribed both in the head and in the rest of the body. Southern blot analysis suggested the presence of a single copy of the gene in the genome. Western blot indicates that the quantity of CYC protein does not fluctuate under LD 12:12 in either the head or the rest of the body. Immunocytochemical examination revealed CYC-like antigen in the pars intercerebralis, dorsolateral protocerebrum, dorsal optic tract, tritocerebrum of the brain and the subesophageal ganglion.