On the relative position of the centromere of chromosome 3 inDrosophila melanogaster

Zusammenfassung HomozygoteDrosophila-melanogaster-Weibchen, genetisch markiert mit scarlet (st), Kinked (Ki) und pink peach (P^p) wurden bestrahlt, um Compound-3-Chromosomen herzustellen. Es wurden ausschliesslich st/st- und P^p Ki/Ki(?) P^p-Compoundchromosomen gefunden. Dies zeigt, dass das Zentromer links der Markierung Kinked liegt.

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This work was supported by Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung.     

Dystrophic mutation (dy2J) affecting regulation of lactate dehydrogenase (LDH) and pyruvate kinase (PK) in C57BL/6J mice

Summary The genotype difference (dystrophic vs nondystrophic) in the LDH isozymes is observed in kidney. These differences are evident only at birth and at early developmental stages (before the expression of dystrophic symptoms). The tissue specific genotype differences for PK are limited to the thigh muscle (M form) and heart (L form), after the onset of the condition. These differences may reflect the pleiotropic effect of the dy^2J locus during the temporal regulation of these and other enzymes implicated in muscular dystrophy (MD).This research was financed by a Natural Sciences and Engineering Research Council Canada grant to S.M.S.     

The antennae and mating behaviour ofDrosophila females

Summary The females ofDrosophila bipectinata andD. malerkotliana are able to discriminate between their own and alien males in the absence of antennae. Thus mate recognition seems to depend on contact chemoreceptors in these 2 species.We are grateful to the Head of the Department of Zoology, B.H.U. for providing the necessary facilities. Thanks are due to the U.G.C., New Delhi, India for awarding a junior research fellowship to O.P.S.     

Lettuce seedling growth: Antagonism between gibberellic acid and Niacin

Zusammenfassung Gibberellin und Niacin sind Antagonisten, Niacin hemmt das Wurzelwachstum vonLactuca sativa, während Gibberellin diese Wirkung teilweise aufhob.     

Effect of hormones on adenyl cyclase activity of rabbit mammary gland in vitro

Ovarian hormones namely beta-estradiol and progesterone were observed to stimulate the activity of adenyl cyclase of the mammary gland from pregnant rabbit in vitro, unlike the lactating tissue where it was inhibited. On the other hand, non-ovarian hormones like hydrocortisone, prolactin and insulin did not have a similar effect on this enzyme.     

Mécanisme d'action du chloramphénicol dans l'inhibition de la production d'anticorps induite par de différents types d'antigènes

Summary Chloramphenicol (CAF) administered to rabbits during the whole period of immunization, is able to suppress almost completely the antibody response against horse serum albumin and globulins (HSA, HSG) andEscherichia coli: on the other hand, it does not inhibit antibody response to heterologous RBC. The possible mechanism of the inhibiting action of the CAF in antibody response to HSA, HSG andE. coli is discussed, and some hypotheses are put forward on the possible reasons for the different behaviour of CAF on the immune response induced by heterologous RBC.