Activation of juvenile hormone synthesis in vitro by a corpus cardiacum factor from Locusta migratoria

Rembold, Heinz; Schlagintweit, B.; Ulrich, Gabriele M.

doi:10.1016/0022-1910(86)90161-7

Cited by 33 publications

(15 citation statements)

References 15 publications

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“…This system eliminates the problem that accidentally all highly active CA are placed in the experimental or in the control group. It is much preferable to the other if the stimulated activity is related to basal activity, that is, if both a highly active and a slightly active C4 increase the JH output by a similar factor in response to the agent [10,11,37]. In the present study we used both procedures.…”

Section: Discussionmentioning

confidence: 99%

Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Unni

Bhaskaran

Dahm

et al. 1991

Arch Insect Biochem Physiol

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Two analogues of a Manduca sexta allatotropin (Mas-AT) were synthesized. They correspond to the active fragment, amino acids 5-13, of the natural Mas-AT with substitution of norleucine for methionine. ATANA has the structure Val-Glu-Nle-Nle-Thr-Ala-Arg-Gly-Phe-NH2, ATAA is acetylated at the N-terminus. Allatotropic potency was evaluated by measuring the in vitro rates of juvenile hormone (JH) biosynthesis in corpora allata (CA) of M. Sexta. At a concentration of 20 nM, ATANA and ATAA increased JH production in day 0, day 1, and day 3 adult female CA by a factor of 3-8. Larval CA were not affected. These results correspond to activities reported for the natural Mas-At. ATANA did not stimulate pharate adult female CA to produce JH. Stimulation of female CA with ATANA was reversed when the CA were transferred to fresh medium while stimulation with ATAA under the same condition persisted. Exogenous farnesoate was converted to JH-III at a rate exceeding the highest ATANA-stimulated rate. ATANA in addition to farnesoate did not increase JH-III production, but increased JH-II production in addition to the already high production rate for JH-III. It is inferred that Mas-AT stimulates a rate-limiting enzyme in the biosynthesis of farnesoate and its homologues but does not affect epoxidation and methylation.

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Section: Discussionmentioning

confidence: 99%

Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Unni

Bhaskaran

Dahm

et al. 1991

Arch Insect Biochem Physiol

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“…The stability of crude methanol extracts to boiling for 5 min has been reported previously [8]. This stability suggests a small molecular mass for allatotropin I (variously estimated to be 700 to 2,000 daltons [8,12]), and in these two characteristics, locust allatotropin differs from the Manduca allatotropin [V.…”

Section: Discussionmentioning

confidence: 65%

Partial purification and characterization of locust allatotropin I

Gadot

Rafaeli

Applebaum

1987

Arch Insect Biochem Physiol

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Methanol extracts of locust brains, corpora cardiaca (CC), and suboesophageal ganglia (SOG) were separated by gradient and/or isocratic reverse-phase high-performance liquid chromatography (HPLC) and allatotropic activity monitored in the eluted fractions. A major peak of activity, separated by isocratic separation with 12% 2-propano1, designated allatotropin I, exhibited identical retention times in the three tissue extracts. Doseresponse curves of allatotropin I indicate similar content in brain and CCequivalents, whereas optic lobes, similarly separated by isocratic HPLC, contain only one-tenth of this amount of allatotropin. Allatotropin I is resistant to boiling and is susceptible to tryptic and chymotryptic digestion. Methanol extracts of thoracic muscle, Malpighian tubules, fat body or ovaries, similarly prepared and boiled, did not exhibit allatotropic activity at high doses of tissue equivalents. *Abbreviations: CA = corpora allata; CC = corpora cardiaca; EDs0 = effective dose eticiting 50% increase in activity; HPLC = high-performance liquid chromatography; JH-Ill = juvenile hormone Ill; k' = capacity factor; RP = reversed phase; SOG = suboesophageal ganglia; TFA = trifluoroacetic acid.

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“…Brain and corpus cardiacum extracts of adult L. migratoria also indicated the presence of peptides with an allatotropic effect. Two such peptides, one with a molecular weight of about 2 kD (Ferenz & Diehl, 1983) and another between 0.7 and 1.5 kD (Rembold et al, 1986) have been reported in this locust. As for insects with an inhibitory mode of gland control, a trypsinsensitive, heat stable substance, which depressed the rates of JH-biosynthesis was shown to occur in brain extracts of D. punctata (Rankin et al, 1986).…”

Section: The Chemical Nature Of Allatostatins and Allatotropinsmentioning

confidence: 79%

Brain‐controlled synthesis of juvenile hormone in adult insects

Khan

1988

Entomologia Exp Applicata

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Activation of juvenile hormone synthesis in vitro by a corpus cardiacum factor from Locusta migratoria

Cited by 33 publications

References 15 publications

Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Partial purification and characterization of locust allatotropin I

Brain‐controlled synthesis of juvenile hormone in adult insects

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