Démonstration du caractère géographique de la parthénogénèse deSaga pedo Pallas et de sa polyploïdie,par comparaison avec les espèces bisexuéesS. ephippigera Fisch. etS. gracilipes Uvar

Summary The males of two species of Palestine,Saga ephippigera Fisch. andS. gracilipes Uvar have respectively 33 and 31 chromosomes in the diploid state.S. pedo Pallas, a parthenogenetic thelytoc species largely distributed in Europe, has 68 chromosomes and probably represents a tetraploid. The cells of the three species have identical dimensions and the polyploidS. pedo is even the smallest in size.     

La formule chromosomique deSorex minutus L. (Mammalia-Insectivora)

Summary The chromosome complement ofSorex minutus L. has been determined. The caryotype is characterized by a diploid number of 42 and by aNF (fundamental number) of 56. The sex-chromosomes are of theX−Y type usual in mammals. The origin and the evolution of the chromosome set ofS. minutus, S. unguiculatus, andS. araneus have been discussed.      

Association of DNA replication with nuclear membrane in larvae ofChironomus thummi

Summary In the larvae ofChironomus thummi, the newly replicating DNA has been found to be associated with the nuclear membrane, as evidenced by the isolation of DNA nuclear membrane complexes (M-band) of³H-thymidine labelled larvae.Acknowledgment. The authors thank Dr D. S. Pradhan for discussions and encouragement.     

IAA oxidase activity in relation to adventitious root formation on stem cuttings of some forest tree species

Summary IAA oxixase activity was very high in stem cuttings ofSalix tetrasperma andPopulus robusta, which rooted profusely, less in stem cuttings ofHibiscus rosa sinensis which rooted less, and insignificant in those ofEucalyptus citriodora which did not root at all. Protein(s) extracted from the stem cuttings ofE. citriodora inhibited the activity of IAA oxidase as well as root formation on hypocotyl cuttings ofPhaseolus mungo. The possibility of involvement of IAA oxidase activity in the process of adventitious root formation is discussed.The research has been financed by a grant from U.S. Department of Agriculture.     

In situ hybridization of rDNA on chromosomes of the honeybee,Apis mellifera L.

DNA probes containing the repeated rDNA region ofDrosophila melanogaster (coding for e.g. 28S and 18S rRNA) hybridized in situ to distinct regions of two heterologous mitotic chromosomes of the honeybee, identifying the nucleolus organizing regions (NORs). The method allows a rapid establishment of a physical map ofApis mellifera using other DNA probes ofDrosophila. This is the first report on well-defined chromosomal markers in the honeybee.     

Effect of genome size andrrn gene copy numbers of PCR amplification products of 16S rRNA genes from mixed bacterial species

Results and conclusion As determined by image analysis of SYBR green-stained amplification products the experimentally determined ratio corresponded well with the expected ratio calculated from the number ofrrn genes per equimolar amount of DNA in mixtures containing DNA ofEscherichia coli and Thermus thermophilus and DNA ofPseudomonas aeruginosa and T. thermophilus. The values for the pairBacillus subtilis and T. thermophilus showed higher deviation from the predicted value. The dependence of the amount of 16S rDNA amplification products on these two parameters makes it impossible to quantify the number of species present in 16S rDNA clone library of an environmental sample, as long as these two parameters are unknown for these species.     

Polymorphisme des lipoprotéines et des glycoprotéines sériques chez la Truite

Summary It is shown that there are important differences among the serum proteins of 3 different species of trout. We stress that these genetic variations concern the lipoproteins as well as the glycoproteins. Furthermore, 3 serum proteins ofEsox lucius have antigenic determinants common with the serum proteins ofS. gairdneri; they are an ₂-lipoprotein, an ₂-glycoprotein and a -globulin.     

ZNS-aktive Phenylpropylamine vonCatha edulis FORSK. (Celastraceae) kenyanischer Herkunft

Summary The phenylpropylamine fraction ofCatha edulis FORSK. grown in Kenya has been investigated. The major components have been found to be (S)-(–)--aminopropiophenone (1), (+)-norpseudoephedrine (2) and(–)-norephedrine (3). Quantitative ratios of1, 2, 3 in tissues of different age are discussed.

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ZNS-aktive Phenylpropylamine vonCatha edulis FORSK. (Celastraceae) kenyanischer Herkunft

     

Comparative effect of silver ion and gibberellic acid on the induction of male flowers on femaleCannabis plants

Summary Silver ion applied as AgNO₃ to the shoot tip of female plants ofCannabis induces male flowers. It is more effective than gibberellic acid (GA₃) in maintaining the induced state.Acknowledgment. G.S. thanks the Council of Scientific and Industrial Research, New Delhi, India, for the award of a Junior Research Fellowship.     

Interphase differential sensitivity to protein synthesis inhibition

Summary The effect of protein synthesis inhibition during interphase ofAllium cepa L. root meristem cells was studied. Anisomycin and cycloheximide were used in intermittent treatments during interphase of a synchronous cell subpopulation labelled as binucleate by caffeine, and the delays in reaching prophase were recorded. High sensitivity to protein synthesis inhibition was detected in G₁ and in the S/G₂ boundary, while protein synthesis in most of the S and G₂ phase was not required for the normal timing of next prophase.