Jörg Eder

Elimination of the allatotropic activity in locusts by microsurgical and immunological methods: evidence for humoral control of the Corpora allata, hemolymph proteins, and ovary development

Transection of the nervous connections (NCC I) between the brain and the corpus cardiacum (group 1) and injection of anti-brain antibodies inhibited vitellogenin synthesis and ovary development in virgin Locusta migratoria females. Removal of the neurosecretory material by these methods changed the titer and the electrophoretic pattern of hemolymph proteins, including vitellogenin. Transection of NCC I at some distance from the brain resulted in bulbs with 30-200 micron diameter which were filled with stainable neurosecretory material (group 2). Oocyte maturation was delayed in group 2 but normal eggs were laid. The same happened if group 1 animals received daily injections of JH-III. It is concluded that a humoral factor is involved in the activation of JH-III biosynthesis. The factor is transported through the NCC I and is released into the hemolymph as allatotropin.

Partial Structure of Papiliochrome, the Yellow Wing Pigment of the Papilionid Butterflies

Abstract Papiliochrome II, one of the yellow wing pigments of the Papilionid butterfly, Papilio xuthus, can be split into ʟ-kynurenine and a catecholamine derivative, SN-1, by 10-3 n HCI. The latter is hydrolyzed by ɴ HCI into β-alanine and noradrenaline. The structure of SN-1 has been elucidated as N-(β-alanyl)-ʟ-noradrenaline by NMR and MS data as well as by synthesis. Preparation of the N-hydroxysuccinimide ester of benzyloxycarbonyl-β-alanine, its condensation with ʟ-noradrenaline to the corresponding benzyloxycarbonyl protected SN-1 and of N- (β-alanyl)-ʟ-noradrenaline by hydrogenolysis of the protecting group are described.

Correlation of cytochrome c titer and respiration in Apis mellifera: Adaptive response to caste determination defines workers, intercastes and queens

1. 1. In Apis mellifera, the structure of cytochrome c is identical in the larval and adult stages. No immunologically crossreactive precursors or isoenzymes are present in larvae. Total body cytochrome c of individual animals can thus be measured by viroimmunoassay. 2. 2. Cytochrome c was used as an indicator for the respiratory capacity of the mitochondrial mass. Its concentration is 2–3.5-fold higher in queen larvae than in workers, with a maximal difference in the spinning larval stage. Cytochrome c concentration and respiration are directly correlated. It is concluded that, as a response to caste determination, respiratory rates in larvae are regulated by adaptive concentration changes in respiratory chain enzymes, as postulated for long-term adaptations by the near equilibrium hypothesis. 3. 3. A mathematical relationship exists between O2-consumption (R), cytochrome c content (cyt. c) and and body weight (W), the product R·log cyt c being proportional to W. R·log cyt c being proportional to W. 4. 4. For queens and workers reared in the colony, this proportionality is caste-specific and permits the definition of a caste factor C = R·log cyt c/W. The resp. values found are Cqueen = 3.78 and Cworker = 0.62. 5. 5. The caste factor is a biochemical probe for queen determination. Larvae reared in vitro can be classified as workers, intercastes or queens according to their individual C-value.

Inhibition of allatotropic activity and ovary development in Locusta migratoria by anti-brain-antibodies.

Evidence for an immunogenic allatotropic factor in the brain of Locusta migratoria is presented. Antibodies to brain material from mature females were raised in rabbits. In vivo injection of these antibodies into young locusts inhibited ovary development and resulted in hypertrophic as well as necrotic corpora allata. Antibodies to brains without neurosecretory material were not able to block allatotropic or gonadotropic activity.

Immunoassay for honey bee cytochrome c in single animals with cytochrome c-coated bacteriophages: A sensitive tool for the study of caste formation in the honey bee, Apis Mellifera

The development of a sensitive viroimmunoassay for honey bee cytochrome c and its usage for early detection of caste differentiation is described. Pure honey bee cytochrome c was isolated from workers and used to produce antibodies in rabbits. Bacteriophage T4 was chemically modified by covalent attachment of honey bee cytochrome c using tolylene-2,4-diisocyanate as a cross-linking agent. The immunospecific inactivation of this bacteriophage-cytochrome c conjugate by anti-cytochrome c antibodies can be inhibited by free cytochrome c. In quantitative determinations, 50% inhibition is reproducibly achieved at a concentration of 6 ng/ml (5 pmol/ml) and as little as 0.3 ng/ml (0.25 pmol/ml) could be detected by this system. Cytochrome c concentrations were measured in individual animals and substantial differences corresponding larval stages of worker and queen bees are reported.

Zum Wirkungsmechanismus der Pteridindiuretica

Summary2,4-Diamino-6,7-dimethyl-pteridine is a potent diuretic agent, exhibiting a marked sodium excretion as well as a reduction of the potassium output. By means of a special analytical method for comparative chromatography, a complete metabolic transformation of this substance by rats could be shown. As main metabolic product 2,4-diamino-7-methyl-pteridine-carboxylic-acid-(6) was isolated from urine. Unequivocal evidence for the chemical structure of the excreted compound is presented by UV-, NMR-, and mass spectrometry, as well as by chemical synthesis. In addition to the appearance of this metabolite, a simultaneous strong decrease of normal uric acid excretion was found. The conversion of the diuretic agent into the excreted metabolite obviously implies a biological inactivation: the metabolite being administered to rats, no diuretic acitivity is observed and uric acid excretion is not affected.Zusammenfassung2,4-Diamino-6,7-dimethyl-pteridin ist ein sehr potentes Diureticum, das eine starke Natriumausscheidung bei gleichzeitiger Kaliumretention bewirkt. Mit Hilfe einer speziellen Methode für vergleichende analytische Chromatographie konnte gezeigt werden, daß diese Verbindung von der Ratte quantitativ umgewandelt wird. Als Hauptmetabolit erscheint 2,4-Diamino-7-methyl-pteridin-carbonsäure-(6) im Harn. Die Struktur der ausgeschiedenen Verbindung wurde durch UV-, NMR- und Massen spektren sowie durch Synthese bewiesen. Gleichzeitig mit dem Auftreten des Metaboliten sinkt die im Harn ausgeschiedene Harnsäuremenge drastisch ab. Eine Veränderung des Serumharnsäurespiegels konnte nicht festgestellt werden. Die beobachtete Wirkung bedeutet zugleich eine Inaktivierung des Diureticums: verfüttert man den Metaboliten, so findet man keine vergleichbare diuretische Wirkung und die Harnsäure ausscheidung der Ratte ändert sich nicht.

Immunochemical Characterization of Porphyridium cruentum B-Phycoerythrin: Proof of Cross-Reaction between Chromophore-Free Apoprotein and Holoprotein-Specific Antibodies

Abstract Antibodies against phycobilisom es of Porphyridium cruentum immunoreact with B-phycoerythrin from the same organism. A strong antigen-antibody complex is not only formed with the native B-phycoerythrin but also when the chromophore is chemically reduced, split or even degraded with chromic acid. Characteristics of precipitations and dissolutions in the presence of the chaotropic reagents urea and potassium rhodanide are discussed for the immunocomplex with native B-phycoerythrin. A sandwich-type immunoadsorbent column appropriate for antigen-isolation is described; its binding properties are investigated biochem ically and by electron microscopy.