Nachweis von Reflex-Bluten bei Lampyriden (Coleoptera) mit Hilfe der „Tracer”-Methode

Summary The very short time (5–9 min) between injection of radiophosphorous into the hemolymph of adult fireflies (Lampyridae) and outflow of radioactive droplets after irritation demonstrates with certainty that reflex-bleeding is involved. Labelling the secretions of dermal glands would require much more time (several h or even 1 day.

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Institut für Angewandte Zoologie der Universität Bonn. Die Untersuchungen wurden 1972 während eines Aufenthaltes vonW. J. Kloft als Visiting Professor an der University of Florida durchgeführt.     

DNA sequence organisation in relation to genome size in birds

Summary DNA sequence interspersion was investigated in pheasant and pelican nuclear DNA. As is typical for birds, these genomes are organized in a long period pattern. Altogether, 5 bird species with genome sizes between 1.6 and 1.9 pg DNA are compared with regard to the extent of repetitive and single copy sequence interspersion. The result indicates that the average length of interspersed repetitive sequences increases with genome size.Acknowledgment. This work was supported by the Deutsche Forschungsgemeinschaft. Mrs H. Tuczynski and Mr J. S. Jackson are thanked for editorial assistance.     

Effect of lesions of the locus coeruleus complex on the circadian rhythm of plasma corticosterone in the mouse

Summary An apparently transient elevation of basal morning (08.00 h) plasma corticosterone levels in male mice was found 48 h after bilateral electrolytic lesions of the brainstem locus coeruleus complex but was not observed 6 weeks after lesioning.Supported by Alfred P. Sloan Foundation research fellowships awarded to W.G. Luttge and S.F. Zornetzer.     

Comparison of the localization of several muscle proteins in relaxed and contracted myofibrils.

The localization of several muscle proteins in relaxed and contracted myofibrils is compared. The morphology of the myofibrils and the behavior of these proteins was also investigated under extraction conditions.     

Molt induction in lobsters (Homarus americanus) by intramuscular injection of ecdysterone triacetate

Summary The principal component of the successful, molt-inducing ecdysterone acetate mixture was established as ecdysterone triacetate and shown to have the same activity as the acetate mixture. The triacetate induced ecdysis in male lobsters collected in winter and summer and in female lobsters collected in winter. Intramuscular injections of triacetate in ethanol were as effective as those with oil emulsions.We thank Dr A. G. McInnes and D. Smith of the Atlantic Regional Laboratory, N. R. C., Halifax for obtaining the NMR-spectrum.