Ecdysteroid titres and location in developing eggs of Schistocerca gregaria

Scalia, Santo; Sbrenna-Micciarelli, A.; Sbrenna, G.; Morgan, E. David

doi:10.1016/0020-1790(87)90164-8

Cited by 30 publications

(24 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This may provide satisfactory Fig. 2; the formation of free ecdysteroid within the embryo of Schistocerca has been calculated from values given by Scalia et al, 1987. experimental evidence for validity of the reciprocal, high ecdysteroid -low metabolism metamorphosis rule in insect embryogenesis.…”

Section: Relations Between the Metabolic Depression And Ecdysteroid Pmentioning

confidence: 98%

“…This shows that the rule of inverse metabolic-ecdysteroid relationships (Sláma, 1982) can be applied to insect morphogenetic process in general. The eggs of Schistocerca are a very convenient model for ecdysteroid-metabolic interactions because the biosyn thesis and metabolism of ecdysteroids have been investi gated in this material by a number of authors Scalia et al, 1987;Tawfik et al, 1999; see also reviews by Hoffmann & Lageux, 1985;Steel & Vafopoulou, 1989;Sbrenna, 1991).…”

Section: Ecdysteroid-metabolic Relationships During Embryogenesismentioning

confidence: 99%

“…The eggs of Schistocerca have been selected because biosynthesis and metabolism of ecdysteroids have been intensively investi gated and are probably the best known (cf. Gande & Mor gan, 1979;Scalia et al, 1987;Tawfik etal., 1999).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Correlation between metabolic depression and ecdysteroid peak during embryogenesis of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Sláma¹

2000

Eur. J. Entomol.

View full text Add to dashboard Cite

Abstract. Respiratory metabolism of developing eggs of Schistocerca gregaria has been individually monitored by means of scan ning microrespirography. The freshly oviposited eggs consumed 7 nl of O2 /min./egg (50 pl 0 2 /g/h) while the pharate 1st instar larvae shortly before hatching consumed 141 nl of 02/min./egg (550 pl 0 2 /g/h), which shows 20-fold metabolic increase during the egg stage. The output of C 02 was also regular, without discontinuous bursts throughout the whole embryonic development. The amounts of C 02 produced were constantly close to R.Q. ratio of 0.7, suggesting that lipid was the main energetic source. The vermi form, pharate 1st instar larvae emerging from the eggs exhibited very high respiratory rates (up to 3,000 pl 0 2/g/h). During initial phases of the egg stage, 0 2 consumption steadily increased until day 6, which was associated with katatrepsis or blastokinesis stage of the embryo (61 nl of 0 2/egg/min. = 240 pl 0 2/g/h). Since blastokinesis, respiratory metabolism of the egg remained constant or decreased steadily until day 10, when it rose sharply again towards hatching. The temporary metabolic depression was closely corre lated with endogenous peak in ecdysteroid concentration within the embryo. These results corroborate validity of the reciprocal, high ecdysteroid -low metabolism rule previously known from insect metamorphosis. They extend its application into the period of embryogenesis. Practical implications of certain physiological, morphological and evolutionary consequences of these findings are discussed with special emphasis on the connecting links between embryogenesis and metamorphosis.

show abstract

Section: Relations Between the Metabolic Depression And Ecdysteroid Pmentioning

confidence: 98%

Section: Ecdysteroid-metabolic Relationships During Embryogenesismentioning

confidence: 99%

See 1 more Smart Citation

Correlation between metabolic depression and ecdysteroid peak during embryogenesis of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Sláma¹

2000

Eur. J. Entomol.

View full text Add to dashboard Cite

show abstract

“…The importance of active ecdysteroids in the developing embryo was also shown in the fruit fly Drosophila melanogaster, in which morphological disruptions were observed when the metabolic pathway for 20-hydroxyecdysone biosynthesis was deleted. In addition, active ecdysteroids are converted from ovary-derived ecdysteroid phosphates in other insects such as the desert locust Schistocerca gregaria (Scalia et al 1987), the oriental migratory locust Locusta migratoria (Lagueux et al 1977), the cockroach Blaberus craniifer (Bullière et al 1979), and the tobacco hornworm Manduca sexta ), suggesting that they play an important role in controlling early embryonic development. Thus, the importance of free ecdysteroids in the eggs and their conversion by EPPase is becoming widely recognized in insects.…”

mentioning

confidence: 99%

Ecdysteroids during Early Embryonic Development in Silkworm Bombyx mori: Metabolism and Functions

2004

View full text Add to dashboard Cite

“…1) (4,5). It has been suggested that free ecdysteroids are liberated from maternal ecdysteroid-phosphates during embryonic development and participate in the secretion of serosal cuticle and/or the induction of embryonic cuticulogenesis (embryonic molt) in various insects, such as Locusta migratoria (6), Schistocerca greagaria (7), Blaberus craniifer (8), and Manduca sexta (9). Furthermore, the involvement of ecdysteroids in embryonic diapause has also been suggested in Lepidosphes ulmi (10), Bombyx mori (11), and L. migratoria (12).…”

mentioning

confidence: 99%

Purification, Kinetic Characterization, and Molecular Cloning of a Novel Enzyme Ecdysteroid-phosphate Phosphatase

Yamada

Sonobe

2003

Journal of Biological Chemistry

View full text Add to dashboard Cite

From eggs of the silkworm Bombyx mori, we isolated a novel enzyme that is involved in the conversion of physiologically inactive conjugated ecdysteroids, such as ecdysone 22-phosphate and 20-hydroxyecdysone 22-phosphate, to active free ecdysteroids. This enzyme, called ecdysteroid-phosphate phosphatase (EPPase), was located in the cytosol fraction and differed from nonspecific lysosomal acid phosphatases in various enzymic properties. EPPase was purified about 3,000-fold to homogeneity by seven steps of column chromatography. The cDNA clone encoding EPPase was isolated by reverse transcription polymerase chain reaction using degenerate primers on the basis of the partial amino acid sequence obtained from purified EPPase and by subsequent 3-and 5-rapid amplification of cDNA ends. The full-length cDNA of EPPase was found to be composed of 1620 bp with an open reading frame encoding a protein of 331 amino acid residues. A data base search showed that there was no functional protein with the amino acid sequence identical to that of EPPase. Northern blot analysis revealed that EPPase mRNA was expressed predominantly during gastrulation and organogenesis in nondiapause eggs but was not detected in diapause eggs whose development was arrested at the late gastrula stage. In nondiapause eggs, the developmental changes in the expression pattern of EPPase mRNA corresponded closely to changes in the enzyme activity and in the amounts of free ecdysteroids in eggs.In insects, ecdysteroids, which regulate development and reproduction, are synthesized in prothoracic glands. However, in many insect species, ecdysteroids have been demonstrated to be synthesized in ovaries as well, to accumulate in mature ovaries, and to be transferred to eggs (1-3). Most of these ecdysteroids are physiologically inactive phosphoric esters and synthesized by the enzyme, ATP:ecdysteroid-phosphotransferase (ecdysteroid kinase), which catalyzes phosphorylation of ecdysteroids ( Fig. 1) (4,5). It has been suggested that free ecdysteroids are liberated from maternal ecdysteroid-phosphates during embryonic development and participate in the secretion of serosal cuticle and/or the induction of embryonic cuticulogenesis (embryonic molt) in various insects, such as Locusta migratoria (6), Schistocerca greagaria (7), Blaberus craniifer (8), and Manduca sexta (9). Furthermore, the involvement of ecdysteroids in embryonic diapause has also been suggested in Lepidosphes ulmi (10), Bombyx mori (11), and L. migratoria (12).In B. mori, recently, it has been demonstrated that the continuous supply of 20-hydroxyecdysone (20E), 1 which has been demonstrated to be an active molecule in B. mori eggs (13), is required for embryonic development and that a deficiency of 20E induces embryonic diapause (13); that is, the cessation of embryonic development at the late gastrula stage (14,15). Furthermore, 20E was demonstrated to be formed by de novo synthesis (16 -18) and dephosphorylation of 20-hydroxyecdysone 22-phosphate (20E22P) and ecdysone 22-phosphate (E22P) (in the c...

show abstract

Ecdysteroid titres and location in developing eggs of Schistocerca gregaria

Cited by 30 publications

References 30 publications

Correlation between metabolic depression and ecdysteroid peak during embryogenesis of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Correlation between metabolic depression and ecdysteroid peak during embryogenesis of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Ecdysteroids during Early Embryonic Development in Silkworm Bombyx mori: Metabolism and Functions

Purification, Kinetic Characterization, and Molecular Cloning of a Novel Enzyme Ecdysteroid-phosphate Phosphatase

Contact Info

Product

Resources

About