Pheromonotropic activity in the gypsy moth Lymantria dispar: evidence for a neuropeptide

The pheromonal gland of Lymantria dispar: morphology and evidence for its innervation

The morphological features of the glandular epithelium that secretes pheromone in the polyphagous pest gypsy moth Lymantria dispar are described by light and electron microscopy. The monolayered gland cells are covered by the folded cuticle of the intersegmental membrane between the 8th and 9th abdominal segments showing neither sites of discontinuity nor distinct openings on its external surface. The cells bear a large, often irregularly shaped nucleus, and contain granules of variable amount and electron-density. These granules are mostly located in the basal compartment of the cytoplasm, in a labyrinthine zone laying on a basement membrane. The apical membrane of the gland cells bear microvilli and cell-cell contact is established by different junctional structures. Nerve fibers enwrapped in glia are found beneath the basement membrane, in close contact with the secretory cells. This latter finding represents the first evidence of the innervation of the pheromonal gland in L. dispar.

Isolation and identification of a pheromonotropic neuropeptide from the brain-suboesophageal ganglion complex of Lymantria dispar: a new member of the PBAN family

A pheromonotropic peptide was isolated from brain-suboesophageal ganglion complexes of the adult female gypsy moth, Lymantria dispar, using a 5-step HPLC purification protocol and an in vivo bioassay in Helicoverpa zea. The intact peptide was sequenced by automated Edman degradation. The L. dispar pheromone biosynthesis activating neuropeptide (Lyd-PBAN) is a C-terminally amidated 33-amino acid peptide with a molecular weight of 3881. The peptide was synthesized using Fmoc procedures. Lyd-PBAN has sequence homology with Hez-PBAN (81.8%) and Bom-PBAN-I (66.7%). All three PBANs share the C-terminal hexapeptide sequence, Tyr-Phe-Ser-Pro-Arg-Leu-NH2. In addition, the C-terminal pentapeptide sequences of Pseudaletia pheromonotropin (Pss-PT), Bombyx diapause hormone (Bom-DH), the locustamyotropins (Lom-MT) and leucopyrokinin (Lem-PK) are identical or have a high degree of homology to the C-terminus of PBANs.