Characters and expression of the gene encoding DH, PBAN and other FXPRLamide family neuropeptides in Antheraea pernyi

Abstract

AbstractThe full‐length cDNA encoding diapause hormone (DH) and pheromone biosynthesis activating neuropeptide (PBAN) in Antheraea pernyi (Anp‐DH‐PBAN) were cloned and sequenced by rapid amplification of cDNA ends methods. The Anp‐DH‐PBAN cDNA encodes a 196‐amino acid (aa) prehormone that contains a 24‐aa DH‐like peptide, a 33‐aa PBAN and three other neuropeptides, all of which share a common C‐terminal pentapeptide motif FXPR/KL (X = G, T, S). The Anp‐DH‐PBAN shows highest homology (82%) to that of Samia cynthia ricini at amino acid level. Northern blots demonstrate the presence of a 0.8‐kb transcript in the brain and suboesophageal ganglion (SG) complex. During the early pupal stages, the Anp‐DH‐PBAN mRNA contents increase consistently in both diapause‐ and non‐diapause‐destined pupae. From day 7, mRNA in diapause pupae dropped promptly and maintained a lower level than that in the non‐diapause type. The Anp‐DH‐PBAN mRNA was expressed mainly in SG, at much lower levels in brain and thoracic ganglia (TG), but not in non‐neural tissues. FXPRLamide (Phe‐X‐Pro‐Arg‐Leu) peptide immunoreactivity was detected in the SG, TG and terminal abdominal ganglion of A. pernyi by whole‐mount immunocytochemistry. The titres of FXPRLamide peptides in the haemolymph in diapause type are consistently lower than in non‐diapause insects. In non‐diapause individuals, there are two peaks of FXPRLamide titres, day 2 in the wandering stage and day‐5 in the pupal stage respectively.