Cosmic influences on the expression of a specific gene in the Colorado potato beetle: the diapause protein 1 gene

Abstract

Diapause protein 1 from the Colorado potato beetle, Leptinotarsa decemlineata, belongs to the family of insect storage hexamers. The protein accumulates in the hemolymph of last instar larvae and in adults reared under short-day (diapause-inducing) conditions. The protein disappears during metamorphosis, but remains in the hemolymph during diapause. The gene which encodes diapause protein 1 encompasses about 9 kb of chromosomal DNA and is composed of 5 exons, separated by 4 introns. The gene is expressed in last-instar larvae and in adults reared under short-day conditions. The messenger RNA for diapause protein 1 occurs only in the fat body. Gene expression is higher in the fat body from short-day adults than from last-instar larvae. Transcription is suppressed after topical application of pyriproxyfen, a JH-analog. The messenger RNA of the protein (approximately 2.3 kb) contains genetic information of a pre-protein of 702 amino acids, including a signal peptide of 17 amino acids and protein of 685 residues. The function of diapause protein 1 is unknown, but it is utilized during post-diapause development, probably for regeneration of the flight muscles.