Storage proteins are present in the hemolymph from larvae and adults of the Colorado potato beetle

Abstract

The protein composition of larval and adult hemolymph from the Colorado potato beetle, Leptinotarsa decemlineata, was investigated and some abundant, high molecular weight proteins were identified and characterized. Diapause protein 1, which occurs in the hemolymph of last instar larvae and short-day adults, appeared to be a storage protein. This protein dissociated into two bands due to the high pH used in nondenaturing gels. Its quaternary structure was established by chemical crosslinking. It appeared to be a hexamer. Diapause protein 1 is composed of approximately 82,000 subunits. The amino acid composition and N-terminal sequence of this protein has been determined. Specific antibodies against diapause protein 1 have been developed. Topical application of 1 microgram pyriproxyfen, a juvenile hormone analog, to last instar larvae and short-day adults suppressed the appearance of this protein in the hemolymph. Pyriproxyfen prematurely induced vitellogenin, when applied to last instar larvae. A larval specific protein was also identified in the hemolymph. Its temporary appearance in the hemolymph of last instar larvae, its subunit composition (M(r) approximately 82,000) and its suppression by pyriproxyfen suggests that this protein is a storage protein as well.

An 86 kDa diapause protein 1‐like protein is a component of early‐staged encapsulation‐relating proteins in coleopteran insect, Tenebrio molitor larvae1

“…As shown in Fig. 2B, the sequence identity between the 86 kDa protein and diapause protein 1 was 43.3% [20], suggesting that the 86 kDa protein is a diapause protein 1‐like protein. This result indicated that diapause protein 1‐like protein is a component of early‐staged ERPs in T. molitor larvae.…”

“…There were three potential N ‐glycosylation sites (Asn‐Xaa‐Ser/Thr) (indicated as closed diamonds). We searched for sequence homology between the sequence of the 86 kDa ERP and those in the NCBI database, and found that the deduced amino acid sequence of the 86 kDa protein was in good coincidence with that of the well‐known diapause protein 1 [20]. As shown in Fig.…”

Population dependent effects of photoperiod on diapause related physiological traits in an invasive beetle (Leptinotarsa decemlineata)

“…A dose of 1 μg in 3 μl of acetone was applied once, at the age of 1 day after adult eclosion (Koopmanshap et al 1989). This dose was the smallest which successfully delayed or terminated diapause in L. decemlineata from a Dutch laboratory population reared in diapause inducing conditions in a previous study, and which incurred no mortality in treated beetles (Koopmanschap et al 1989(Koopmanschap et al , 1992. In contrast to increasing the JH titers, decreasing natural JH titers is more challenging and was in the present study attempted by using H17, an allatostatin mimic (kindly provided by Dr. Xingling Yang, China Agricultural University).…”

Regulation of JH titers: The relevance of degradative enzymes and binding proteins

“…Other evidence that higher levels of JH are required to elicit reproduction comes from experiments in which JH analogs (methoprene or pyriproxyfen) were topically applied to last instars. In addition to disrupting metamorphosis, the rather high concentrations used on larvae of L. migratorzu, Leptinotarsa decemlineata, and Leucophaea maderae also induced premature vitellogenin synthesis (Dhadialla and Wyatt, 1983;de Kort and Kooprnanschap, 1991;Koopmanschap et al, 1992;Don-Wheeler and Englemann, 1991).…”