Studies on the C-2 hydroxylation of 2-deoxyecdysone in Locusta migratoria

Kappler, Christine; Kabbouh, Mohamed; Durst, Francis; Hoffmann, Jules A.

doi:10.1016/0020-1790(86)90074-0

Cited by 45 publications

(6 citation statements)

References 10 publications

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“…Follicle cells of ovaries of Bornbyx mori produce 2-deoxyE as well [21]. Although 2-deoxyE has been shown to be a precursor or E and 20HE [9,21,22] our data, obtained under in vitro conditions, in which 2-10 times more [3H]E than the physiological titer of E in H . virescens testes [12] was added to the incubation mixture, do not indicate that this pathway was followed.…”

Section: Discussioncontrasting

confidence: 50%

Metabolism of ecdysteroid by testes of the tobacco budworm, Heliothis virescens

Loeb

Woods

1989

Arch Insect Biochem Physiol

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Testes from late last stage larvae of the tobacco budworm, Heliothis virescens, were incubated with [3H]ecdysone and [3H]cholesterol. 13HlEcdysone was converted to six other major ecdysteroids, identified by cochromatography in reverse-phase high-pressure liquid chromatography (RPHPLC); four of them were verified by normal-phase HPLC. A highly polar fraction, moderately polar ecdysteroids (20,26-dihydroxyecdysone, 3-epi-20-hydroxyecdysonef and 20-hydroxyecdysone) and low-polarity ecdysteroids, including 2-deoxyecdysone, were detected after incubation with 13H]ecdysone. Compounds that reacted positively to antibodies to progesterone and testosterone were detected in the low-polarity fractions. Testes were incubated in fractions corresponding to each of the major ecdysteroid peaks derived from [3H]ecdysone metabolism. Although most of the radioactive ecdysteroid fractions were further metabolized to high-and low-polarity endpoints, 88% of the [3H]20-hydroxyecdysone peak apparently remained unmetabolized. 20-Hydroxyecdysone may be the primary ecdysteroid product of testes of H. virescens. [3HlCholesterol was not metabolized to any appreciable extent.

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Section: Discussioncontrasting

confidence: 50%

Metabolism of ecdysteroid by testes of the tobacco budworm, Heliothis virescens

Loeb

Woods

1989

Arch Insect Biochem Physiol

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“…The isolation of the postulated intermediates from ovaries of L. migratoria meets criterium (1). Recent work on enzyme systems of Locusta (Kappler et al, 1986) also fulfills requirements of criterium (5). Nevertheless we are aware of the necessity also to satisfy the other criteria before the pathway of ecdysone biosynthesis via 5,8-ketodiol can be taken as demonstrated.…”

Section: Discussionmentioning

confidence: 86%

Conversion of a Radiolabelled Putative Ecdysone Precursor, 2,22,25-Trideoxyecdysone (5β-Ketodiol) in Larvae and Pupae ofCalliphora vicina

Meister

Brandtner

Koolman

et al. 1987

International Journal of Invertebrate Reproduction and Developm

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When a tritiated ecdysone precursor, 2,22,25-trideoxyecdysone (5,8-ketodiol) was injected into larvae and pupae of Calliphora vicina, it was efficiently converted into 20-hydroxyecdysone. Injections into the anterior and posterior compartments of neck-ligated larvae have shown that both parts can hydroxylate the 5,8-ketodiol at C-25, C-22 and C-2 to form ecdysone which was readily hydroxylated at C-20 to form 20-hydroxyecdysone. When incubated with larval brain-ring gland complexes, 5,8-ketodiol was converted to ecdysone as well as to other metabolites, such as 22,25-dideoxyecdysone and 2-deoxyecdysone. Other larval tissues, namely the fat body, Malpighian tubules, gut and carcass are also able to transform 5,8-ketodiol into ecdysone in vitro, which explains the conversion of the 5Q-ketodiol injected into the abdominal portions of neck-ligated larvae. The large tissue distribution of the enzyme systems involved in the terminal hydroxylations of ecdysteroid biosynthesis in discussed in view of the results obtained in this and other insect orders. ecdysone biosynthesis, ring gland, Calliphora, blowfly, radio-labelled 5,8-ketodiol 0168-8170/87/$03.50 1Cl1987 Balaban

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“…Biochemically mitochondria of Locusta migratoria have been shown to be capable of C2-hydroxylation (Kappler et al, 1986), the terminal enzymatic step in ecdysone biosynthesis in Manduca sexta prothoracic glands (Bollenbacher et al, 1977). Any changes in number or morphology of mitochondria could therefore be interpreted as morphological correlates of physiological changes.…”

Section: Discussionmentioning

confidence: 98%

Structure and function of the prothoracic gland in honey bee (Apis melliferaL.) development

Hartfelder¹

1993

Invertebrate Reproduction & Development

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The prothoracic gland of honey bee larvae was identified, and its developmental characteristics were assessed by a combination of histological and physiological methods. The reticulate gland is attached to the intestinal tract at the junction of the esophagus and midgut. Ultrastructurally prothoracic gland cells show the typical characteristics of ecdysteroid-producing cells, i.e., a deep plasma membrane reticular system and extensive smooth as well as rough endoplasmic reticulum. Small lipid vacuoles bounded by flattened SER sacs were found in considerable numbers shortly before commencement of ecdysteroid synthesis. An element apparently unique to prothoracic gland cells of honey bees are tracheoles, which penetrate deeply into the gland. Ecdysteroid production of isolated glands was monitored in vitro by RIA analysis of released products. Developmental profiles for hormone production in prothoracic glands of queen and worker larvae showed a high correlation to caste-specific differences in hemolymph ecdysteroid titer. Control tissue did not liberate significant amounts of RIA-active material during decisive developmental phases.

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Studies on the C-2 hydroxylation of 2-deoxyecdysone in Locusta migratoria

Cited by 45 publications

References 10 publications

Metabolism of ecdysteroid by testes of the tobacco budworm, Heliothis virescens

Metabolism of ecdysteroid by testes of the tobacco budworm, Heliothis virescens

Conversion of a Radiolabelled Putative Ecdysone Precursor, 2,22,25-Trideoxyecdysone (5β-Ketodiol) in Larvae and Pupae ofCalliphora vicina

Structure and function of the prothoracic gland in honey bee (Apis melliferaL.) development

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