cDNA sequence and gene expression of storage protein-2-a juvenile hormone-suppressible hexamerin from the fall webworm, Hyphantria cunea Drury

摘要

We isolated and sequenced a cDNA clone corresponding to storage protein-2 (SP-2) from the fall webworm Hyphantria cunea. The cDNA for SP-2 (2572 bp) codes for a 747-residue protein with a predicted molecular mass of 88.~ kDa. The calculated isoelectric point is 7.6. Multipte alignment analysis of amino acid sequence revealed that SP-2 i: most similar to BJHSP2 (74.3% identity). According to both the phylogenetic analyses and criteria for amino aci( composition, SP-2 belongs to the subfamily of moderately methionine-rich storage proteins (3.2% methionine, 11.80;1 aromatic amino acid). Topical application of the JH analog, methoprene, after head ligation of larvae, suppresse( transcription of the SP-2 gene, indicating hormonal effects at the transcriptional level. The SP-2 transcript was detecte( by Northern blot analysis in Malpighian tubules, in addition to the fat body where it was most abundant. The loca expression of SP-2 in Malpighian tubules suggests that it may have some function in that organ.