Cloning of a putative juvenile hormone‐responsive storage protein gene from the tobacco budworm, Heliothis virescens

Abstract

A cDNA clone with 78% amino acid identity to a basic juvenile hormone (JH)-suppressible hemolymph protein from the cabbage looper, Trichoplusia ni, was isolated from the tobacco budworm, Heliothis virescens. This clone was obtained upon screening a cDNA library derived from larval fat body of a pesticide resistant strain of H. virescens with a cDNA probe for Drosophila melanogaster glutathione S-transferase. By comparison with other insect storage proteins, this clone was predicted to be part of an approximately 2,300 nucleotide (nt) cDNA, of which 691 nt were isolated and sequenced. The partial cDNA clone hybridizes to a RNA of approximately 2,370 nt in H. virescens. Treatment with a juvenoid (2-[1-methyl-2-(4-phenoxyphenoxy)ethoxy] pyridine; pyriproxifen) leads to a decrease in RNA levels of this putative hemolymph storage protein in early fifth stadium larvae of H. virescens, prior to commitment. In contrast, treatment in late fifth stadium (after commitment to pupal development) leads to an increase in the RNA level of this JH-responsive gene. This is the first report of both induction and suppression of storage protein RNA levels in the same stadium. We have given this gene the designation Hv-SP4 (H. virescens, storage protein 4; accession no. U48594). Genetic segregation analysis of restriction fragment length polymorphisms (RFLPs) defined by Hv-SP4 has shown that it is the product of a single-copy, Mendelian, autosomal gene.