Comparable activities of left and right corpora allata consistent with humoral control of juvenile hormone biosynthesis in the cockroach

1979 ◽  
Vol 57 (2) ◽  
pp. 343-345 ◽  
Author(s):  
R. J. Weaver
Keyword(s):  
Juvenile Hormone ◽  
Periplaneta Americana ◽  
Corpora Allata ◽  
Endocrine Activity ◽  
Humoral Factors ◽  
Mature Adult ◽  
Juvenile Hormone Biosynthesis ◽  
Left And Right ◽  
Reproductive Cycles

The rates of juvenile hormone (JH) biosynthesis have been measured in vitro for individual members of the paired corpora allata (CA) in the cockroach Periplaneta americana during the first two reproductive cycles. A marked similarity of endocrine activity between left and right glands of the majority of animals was observed, even though total JH biosynthesis by the gland pairs can differ up to 200-fold during this period. In a small number of immature females only one gland in the pair had the capacity to synthesize hormone. These results support the use of 'split pairs' of CA from mature, adult female P. americana in short-term in vitro radioassay of potential exogenous and endogenous modulators of JH biosynthesis, such that each sample bioassayed has a valid control. Furthermore, the observations suggest that, after a short postecdysial period (up to 4 days), the CA of this species are controlled by one or more humoral factors.

scholarly journals The influence of substrate concentrations on the rate of insect juvenile hormone biosynthesis by corpora allata of the desert locust in vitro

1974 ◽  
Vol 144 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Stephen S. Tobe ◽  
Grahame E. Pratt
Keyword(s):  
Juvenile Hormone ◽  
Schistocerca Gregaria ◽  
Corpora Allata ◽  
Synthetic Activity ◽  
Methyl Farnesoate ◽  
Physiological Concentration ◽  
Juvenile Hormone Biosynthesis ◽  
Hormone Biosynthesis ◽  
Influence Of Substrate

The rate at which isolated corpora allata of adult female Schistocerca gregaria incorporate [3H]farnesenic acid and [14C]methionine into C16juvenile hormone in vitro was examined at different concentrations of farnesenic acid, methionine, O2 and H+ ions. Maximum juvenile hormone biosynthesis is obtained at a farnesenic acid concentration of 20μm. The range of optimum l-methionine concentrations (0.1–0.4mm) encompasses the physiological concentration of this substrate in the haemolymph. Hormone biosynthesis is dependent on O2, but is not stimulated by hyperbaric oxygen tension. The glands had a maximum synthetic activity at pH8.0, but their activity was more reproducible in the the physiological range pH7.0–7.5. At pH6.5 and less, the synthetic ability was considerably decreased. The relative incorporations of the labelled substrates into methyl farnesoate and C16 juvenile hormone indicate that [3H]farnesenic acid comes into isotopic equilibrium within the gland more rapidly than [14C]methionine. The incorporations into methyl farnesoate become stoicheiometric after 20min incubation and into C16 juvenile hormone after a further 10min. Labelled juvenile hormone is detectable after 10min incubation and the rate of incorporation is constant for up to 4h. It is proposed that the described method may be usefully employed to assess the physiological changes in the enzymic competence of the glands to effect the last two stages in C16 juvenile hormone biosynthesis.

scholarly journals Effects of Inhibitors on Juvenile Hormone III Biosynthesis in Corpora Allata of the Cockroach Periplaneta americana L., in Vitro

1984 ◽  
Vol 9 (4) ◽  
pp. 755-758 ◽  
Author(s):  
Gerald T. BROOKS ◽  
Grahame E. PRATT ◽  
Anthony P. OTTRIDGE ◽  
John A. COCKS
Keyword(s):  
Juvenile Hormone ◽  
Periplaneta Americana ◽  
Corpora Allata ◽  
Juvenile Hormone Iii

Juvenile hormone biosynthesis by the corpora allata of the male desert locust, Schistocerca gregaria, during sexual maturation

1978 ◽  
Vol 56 (10) ◽  
pp. 2097-2102 ◽  
Author(s):  
L. I. Avruch ◽  
S. S. Tobe
Keyword(s):  
Juvenile Hormone ◽  
Sexual Maturation ◽  
Time Course ◽  
Schistocerca Gregaria ◽  
Dry Weight ◽  
Corpora Allata ◽  
Gas Liquid Chromatography ◽  
Juvenile Hormone Biosynthesis ◽  
Hormone Biosynthesis

The time course of release of C16 juvenile hormone (JH III) from isolated corpora allata (CA) of male Schistocerca gregaria was followed at selected times during sexual maturation. The rates of JH release over an 8-h incubation period were observed to be directly related to the age of the animals: CA from younger animals showed low rates of release (days 5 and 8) whereas CA from older animals showed intermediate to high rates of release (days 12–13). The mean rate of JH release is linear for at least 4 h. The only biosynthesized JH which could be detected in the incubation medium by radio gas–liquid chromatography was C16JH.The dry weight of the accessory reproductive glands (ARG) was also followed during the period of sexual maturation. This increased rapidly between days 10 and 15 and leveled off thereafter. The biosynthesis of C16JH, as determined by a radiochemical assay in vitro, also increased during this period, suggesting a functional relationship between synthesis of ARG secretion and JH.

Stimulation of Juvenile Hormone Biosynthesis in vitro by Locust Allatotropin

1983 ◽  
Vol 38 (9-10) ◽  
pp. 856-858 ◽  
Author(s):  
Hans-Joerg Ferenz ◽  
Ingrid Diehl
Keyword(s):  
Juvenile Hormone ◽  
Locusta Migratoria ◽  
Corpus Allatum ◽  
Corpora Allata ◽  
Biosynthetic Activity ◽  
Hormone Synthesis ◽  
Heat Stable ◽  
Juvenile Hormone Biosynthesis ◽  
Hormone Biosynthesis

Abstract In Locusta migratoria the gonotrophic cycles are regulated by juvenile hormone. The cyclical changes of juvenile hormone synthesis in locust corpora allata seem to be regulated by a neuro-hormonal factor. Such an allatotropin could be extracted from corpora cardiaca and brains of Locusta migratoria. It is a small pronase-sensitive and heat-stable peptide. Extract of one corpus cardiacum stimulates corpus allatum biosynthetic activity in vitro 5 to 20-fold.

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