IDENTIFICATION OF THE CDNA, GENE AND PROMOTER FOR A MAJOR PROTEIN FROM FLEXIBLE CUTICLES OF THE GIANT SILKMOTH HYALOPHORA-CECROPIA

We have isolated and sequenced a cDNA and region of genomic DNA that e ncode HCCP12, a major protein found in flexible cuticles of all three metamorphic stages of the giant silkmoth, Hyalophora cecropia. The gen e for HCCP12 contains two introns with the first intron interrupting t he signal peptide, The 5' flanking region contains 478 base pairs (bp) with about 95% identity to the prototype of a common Cecropia inserti on element, The RACE procedure was used to produce cDNAs corresponding to the 5' ends of mRNAs for HCCP12 isolated from larval, pupal and ph arate adult epidermal cells. Sequences from 21 cloned cDNAs were almos t identical, It was thus concluded that a single gene and a single pro moter (as evidenced by a single transcriptional start site) for HCCP12 are used in all three metamorphic stages, Hence, neither stage-specif ic gene sets nor stage-specific promoters are essential for metamorphi c transitions of cuticular protein gene expression.