Ecdysteroids from developing eggs of <i>Pieris brassicae</i>

Beydon, Philippe; Permana, Agus-dana; Colardeau, Jacqueline; Morinière, Madeleine; Lafont, René

doi:10.1002/arch.940110102

“…The current study was undertaken to identify components of the CPB egg that might enhance larval development and that may be required by E. puttleri for adult development and emergence. Ecdysteroids have been reported to be present in insect eggs (Lagueux et al, 1979;Hoffmann et al, 1980;Dinan and Rees, 1981;Fournier and Radallah, 1988; Thompson et al, 1988;Beydon et al, 1989) and are likely candidates as molecules that are vital to wasp development. Amino acids have been shown to be essential nutrients for the growth and development of parasitic wasps and flies (Thompson, 1981(Thompson, , 1986Nettles, 1986;Rojas et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Ecdysteroid and free amino acid content of eggs of the Colorado potato beetle, Leptinotarsa decemlineata

Gelman¹,

Rojas²,

Kelly³

et al. 2000

Arch. Insect Biochem. Physiol.

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In order to identify components of the Colorado potato beetle (CPB) egg that may be required by Edovum puttleri, a parasitic wasp that parasitizes the CPB egg, to complete development, ecdysteroid and free amino acid content of CPB eggs were analyzed by reversed phase high pressure liquid chromatography followed by radioimmunoassay to identify ecdysteroids. Ecdysteroid titers were relatively low (<300 pg/egg) through day 2 post-oviposition and then increased sharply, reaching concentrations >2,500 pg/egg on day 3 post-oviposition. Ecdysone (E), 20-hydroxyecdysone (20E), and polar conjugates of E were prominent ecdysteroids present in eggs sampled on days 0 and 1 post-ecdysis, and E, 20E, three peaks containing more polar ecdysteroids (metabolic inactivation products), and polar conjugates of E were present in eggs sampled on day 2. Thus, at a time when parasitization of CPB eggs by E. puttleri is relatively high (0-48 h), physiologically-active ecdysteroids (20E and perhaps E are physiologically active) are present at concentrations between 50 and 200 pg/egg. Ecdysone and 20E reached their highest levels in day-3 eggs, indicating that ecdysteroid may direct physiological processes associated with the completion of CPB embryonic development. In day-4 eggs, the concentration of E and 20E fall dramatically and polar metabolites of E and/or 20E are now responsible for the high ecdysteroid content of the eggs. Interestingly, conjugates of E decrease to relatively low levels in day-3 eggs and are absent in day-4 eggs. Therefore, it is likely that the increase in E in day-3 eggs is due, in part, to the breakdown of polar conjugates of E. Nine amino acids were present in significant quantities in eggs sampled at various times between 0 and 48 h post-oviposition. These include histidine, glutamine, proline, asparagine, serine, glutamic acid, threonine, lysine, and tyrosine. The first three amino acids were present at concentrations that were approximately 2 to 6 times greater than the concentrations of the last six amino acids. Amounts of most of the free amino acids varied with the age of the eggs from which the extract was prepared, but in general, there was no correlation between the levels at times of maximum parasitization (0 and 30 h) and the levels at the less favored times of parasitization (16 and 48 h). This information should facilitate the development of diets for both parasites and predators of pest species of beetles. Arch. Insect Biochem. Physiol. 44:172-182, 2000. Published 2000 Wiley-Liss, Inc.

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“…Ecdysteroids have been reported to be present in insect eggs (Lagueux et al, 1979;Hoffmann et al, 1980;Dinan and Rees, 1981;Fournier and Radallah, 1988; Thompson et al, 1988;Beydon et al, 1989) and are likely candidates as molecules that are vital to wasp development. Amino acids have been shown to be essential nutrients for the growth and development of parasitic wasps and flies (Thompson, 1981(Thompson, , 1986Nettles, 1986;Rojas et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Ecdysteroid and free amino acid content of eggs of the Colorado potato beetle,Leptinotarsa decemlineata

Gelman¹,

Rojas

²

,

Kelly

³

et al. 2000

Arch. Insect Biochem. Physiol.

6

0

View full text Add to dashboard Cite

In order to identify components of the Colorado potato beetle (CPB) egg that may be required by Edovum puttleri, a parasitic wasp that parasitizes the CPB egg, to complete development, ecdysteroid and free amino acid content of CPB eggs were analyzed by reversed phase high pressure liquid chromatography followed by radioimmunoassay to identify ecdysteroids. Ecdysteroid titers were relatively low (<300 pg/egg) through day 2 post-oviposition and then increased sharply, reaching concentrations >2,500 pg/egg on day 3 post-oviposition. Ecdysone (E), 20-hydroxyecdysone (20E), and polar conjugates of E were prominent ecdysteroids present in eggs sampled on days 0 and 1 post-ecdysis, and E, 20E, three peaks containing more polar ecdysteroids (metabolic inactivation products), and polar conjugates of E were present in eggs sampled on day 2. Thus, at a time when parasitization of CPB eggs by E. puttleri is relatively high (0-48 h), physiologically-active ecdysteroids (20E and perhaps E are physiologically active) are present at concentrations between 50 and 200 pg/egg. Ecdysone and 20E reached their highest levels in day-3 eggs, indicating that ecdysteroid may direct physiological processes associated with the completion of CPB embryonic development. In day-4 eggs, the concentration of E and 20E fall dramatically and polar metabolites of E and/or 20E are now responsible for the high ecdysteroid content of the eggs. Interestingly, conjugates of E decrease to relatively low levels in day-3 eggs and are absent in day-4 eggs. Therefore, it is likely that the increase in E in day-3 eggs is due, in part, to the breakdown of polar conjugates of E. Nine amino acids were present in significant quantities in eggs sampled at various times between 0 and 48 h post-oviposition. These include histidine, glutamine, proline, asparagine, serine, glutamic acid, threonine, lysine, and tyrosine. The first three amino acids were present at concentrations that were approximately 2 to 6 times greater than the concentrations of the last six amino acids. Amounts of most of the free amino acids varied with the age of the eggs from which the extract was prepared, but in general, there was no correlation between the levels at times of maximum parasitization (0 and 30 h) and the levels at the less favored times of parasitization (16 and 48 h). This information should facilitate the development of diets for both parasites and predators of pest species of beetles. Arch. Insect Biochem. Physiol. 44:172-182, 2000. Published 2000 Wiley-Liss, Inc.

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Metabolism of ecdysteroids by a chitin‐synthesizing insect cell line

Ward

¹

,

Beydon

²

,

Lafont

³

et al. 1990

Arch Insect Biochem Physiol

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A chitin-synthesizing cockroach cell line (UMBGE-4) previously shown to secrete ecdysteroids was analyzed for its ability to metabolize potential precursors of ecdysone (e.g., 2-deoxyecdysonet 2,22-dideoxyecdysone, 2,22,25-trideoxyecdysone, and cholesterol). All, except cholesterol, were actively metabolized by UMBGE-4 cells. However, all but 2-deoxyecdysone were converted to polar and hydrolyzable metabolites, and not to ecdysone. Labeling with cholesterol was unsuccessful. Labeling experiments with molting hormones, i.e., ecdysone and 20-hydroxyecdysone, confirmed that this cell line can metabolize ecdysteroids and allowed identification of some of the products. Molting hormones were converted into acetate conjugates and polar conjugates which were often double-conjugates, i.e., polar conjugates of acetate conjugates. Labeling experiments with ecdysone demonstrated that this cell line possesses a low ecdysone 20-hydroxylase activity. The capacity of UMBGE-2 cells, which do not synthesize chitin or ecdysteroids, was also examined. Neither ecdysone nor 20-hydroxyecdysone was significantly metabolized by UMBCE-2 cells. 2-Deoxyecdysone and 2,22-dideoxyecdysone were very slowly metabolized respectively to more polar compounds.

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Ecdysteroids from developing eggs of Pieris brassicae

Cited by 15 publications

References 21 publications

Ecdysteroid and free amino acid content of eggs of the Colorado potato beetle, Leptinotarsa decemlineata

Ecdysteroid and free amino acid content of eggs of the Colorado potato beetle, Leptinotarsa decemlineata

Ecdysteroid and free amino acid content of eggs of the Colorado potato beetle,Leptinotarsa decemlineata

Metabolism of ecdysteroids by a chitin‐synthesizing insect cell line

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